Merge trunk

75 files changed, 4113 insertions, 2213 deletions

diff --git a/doc/Tcl.n b/doc/Tcl.n
index 8b17f93..c7fa9f6 100644
--- a/doc/Tcl.n
+++ b/doc/Tcl.n
@@ -108,8 +108,8 @@ Variable substitution may take any of the following forms:
 \fIName\fR is the name of a scalar variable;  the name is a sequence
 of one or more characters that are a letter, digit, underscore,
 or namespace separators (two or more colons).
-Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\-\fB9\fR,
-\fBA\fR\-\fBZ\fR and \fBa\fR\-\fBz\fR).
+Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\(en\fB9\fR,
+\fBA\fR\(en\fBZ\fR and \fBa\fR\(en\fBz\fR).
 .TP 15
 \fB$\fIname\fB(\fIindex\fB)\fR
 .
@@ -117,8 +117,8 @@ Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\-\fB9\fR,
 the name of an element within that array.
 \fIName\fR must contain only letters, digits, underscores, and
 namespace separators, and may be an empty string.
-Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\-\fB9\fR,
-\fBA\fR\-\fBZ\fR and \fBa\fR\-\fBz\fR).
+Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\(en\fB9\fR,
+\fBA\fR\(en\fBZ\fR and \fBa\fR\(en\fBz\fR).
 Command substitutions, variable substitutions, and backslash
 substitutions are performed on the characters of \fIindex\fR.
 .TP 15
@@ -158,25 +158,25 @@ handled specially, along with the value that replaces each sequence.
 .RS
 .TP 7
 \e\fBa\fR
-Audible alert (bell) (0x7).
+Audible alert (bell) (Unicode U+000007).
 .TP 7
 \e\fBb\fR
-Backspace (0x8).
+Backspace (Unicode U+000008).
 .TP 7
 \e\fBf\fR
-Form feed (0xc).
+Form feed (Unicode U+00000C).
 .TP 7
 \e\fBn\fR
-Newline (0xa).
+Newline (Unicode U+00000A).
 .TP 7
 \e\fBr\fR
-Carriage-return (0xd).
+Carriage-return (Unicode U+00000D).
 .TP 7
 \e\fBt\fR
-Tab (0x9).
+Tab (Unicode U+000009).
 .TP 7
 \e\fBv\fR
-Vertical tab (0xb).
+Vertical tab (Unicode U+00000B).
 .TP 7
 \e\fB<newline>\fIwhiteSpace\fR
 .
@@ -194,8 +194,9 @@ Backslash
 \e\fIooo\fR 
 .
 The digits \fIooo\fR (one, two, or three of them) give a eight-bit octal 
-value for the Unicode character that will be inserted, in the range \fI000\fR
-- \fI377\fR.  The parser will stop just before this range overflows, or when
+value for the Unicode character that will be inserted, in the range
+\fI000\fR\(en\fI377\fR (i.e., the range U+000000\(enU+0000FF).
+The parser will stop just before this range overflows, or when
 the maximum of three digits is reached.  The upper bits of the Unicode
 character will be 0.
 .TP 7
@@ -203,23 +204,27 @@ character will be 0.
 .
 The hexadecimal digits \fIhh\fR (one or two of them) give an eight-bit
 hexadecimal value for the Unicode character that will be inserted.  The upper
-bits of the Unicode character will be 0.
+bits of the Unicode character will be 0 (i.e., the character will be in the
+range U+000000\(enU+0000FF).
 .TP 7
 \e\fBu\fIhhhh\fR 
 .
 The hexadecimal digits \fIhhhh\fR (one, two, three, or four of them) give a
 sixteen-bit hexadecimal value for the Unicode character that will be
-inserted.  The upper bits of the Unicode character will be 0.
+inserted.  The upper bits of the Unicode character will be 0 (i.e., the
+character will be in the range U+000000\(enU+00FFFF).
 .TP 7
 \e\fBU\fIhhhhhhhh\fR 
 .
 The hexadecimal digits \fIhhhhhhhh\fR (one up to eight of them) give a
 twenty-one-bit hexadecimal value for the Unicode character that will be
-inserted, in the range U+0000..U+10FFFF.  The parser will stop just
+inserted, in the range U+000000\(enU+10FFFF.  The parser will stop just
 before this range overflows, or when the maximum of eight digits
 is reached.  The upper bits of the Unicode character will be 0.
+.RS
 .PP
-The range U+010000..U+10FFFD is reserved for the future.
+The range U+010000\(enU+10FFFD is reserved for the future.
+.RE
 .PP
 Backslash substitution is not performed on words enclosed in braces,
 except for backslash-newline as described above.
diff --git a/doc/encoding.n b/doc/encoding.n
index be1dc3f..5782199 100644
--- a/doc/encoding.n
+++ b/doc/encoding.n
@@ -14,10 +14,21 @@ encoding \- Manipulate encodings
 .BE
 .SH INTRODUCTION
 .PP
-Strings in Tcl are encoded using 16-bit Unicode characters.  Different
-operating system interfaces or applications may generate strings in
-other encodings such as Shift-JIS.  The \fBencoding\fR command helps
-to bridge the gap between Unicode and these other formats.
+Strings in Tcl are logically a sequence of 16-bit Unicode characters.
+These strings are represented in memory as a sequence of bytes that
+may be in one of several encodings: modified UTF\-8 (which uses 1 to 3
+bytes per character), 16-bit
+.QW Unicode
+(which uses 2 bytes per character, with an endianness that is
+dependent on the host architecture), and binary (which uses a single
+byte per character but only handles a restricted range of characters).
+Tcl does not guarantee to always use the same encoding for the same
+string.
+.PP
+Different operating system interfaces or applications may generate
+strings in other encodings such as Shift\-JIS.  The \fBencoding\fR
+command helps to bridge the gap between Unicode and these other
+formats.
 .SH DESCRIPTION
 .PP
 Performs one of several encoding related operations, depending on
@@ -37,8 +48,9 @@ system encoding is used.
 Convert \fIstring\fR from Unicode to the specified \fIencoding\fR.
 The result is a sequence of bytes that represents the converted
 string.  Each byte is stored in the lower 8-bits of a Unicode
-character.  If \fIencoding\fR is not specified, the current
-system encoding is used.
+character (indeed, the resulting string is a binary string as far as
+Tcl is concerned, at least initially).  If \fIencoding\fR is not
+specified, the current system encoding is used.
 .TP
 \fBencoding dirs\fR ?\fIdirectoryList\fR?
 .
@@ -56,6 +68,11 @@ searchable directory, that element is ignored.
 .
 Returns a list containing the names of all of the encodings that are
 currently available. 
+The encodings
+.QW utf-8
+and
+.QW iso8859-1
+are guaranteed to be present in the list.
 .TP
 \fBencoding system\fR ?\fIencoding\fR?
 .
@@ -73,7 +90,7 @@ However, because the \fBsource\fR command always reads files using the
 current system encoding, Tcl will only source such files correctly
 when the encoding used to write the file is the same.  This tends not
 to be true in an internationalized setting.  For example, if such a
-file was sourced in North America (where the ISO8859-1 is normally
+file was sourced in North America (where the ISO8859\-1 is normally
 used), each byte in the file would be treated as a separate character
 that maps to the 00 page in Unicode.  The resulting Tcl strings will
 not contain the expected Japanese characters.  Instead, they will
@@ -93,3 +110,6 @@ which is the Hiragana letter HA.
 Tcl_GetEncoding(3)
 .SH KEYWORDS
 encoding, unicode
+.\" Local Variables:
+.\" mode: nroff
+.\" End:
diff --git a/doc/string.n b/doc/string.n
index 76005fc..163abdd 100644
--- a/doc/string.n
+++ b/doc/string.n
@@ -343,10 +343,13 @@ misleading.
 \fBstring bytelength \fIstring\fR
 .
 Returns a decimal string giving the number of bytes used to represent
-\fIstring\fR in memory.  Because UTF\-8 uses one to three bytes to
-represent Unicode characters, the byte length will not be the same as
-the character length in general.  The cases where a script cares about
-the byte length are rare.
+\fIstring\fR in memory when encoded as Tcl's internal modified UTF\-8;
+Tcl may use other encodings for \fIstring\fR as well, and does not
+guarantee to only use a single encoding for a particular \fIstring\fR.
+Because UTF\-8 uses a variable number of bytes to represent Unicode
+characters, the byte length will not be the same as the character
+length in general.  The cases where a script cares about the byte
+length are rare.
 .RS
 .PP
 In almost all cases, you should use the
@@ -354,10 +357,27 @@ In almost all cases, you should use the
 Tcl byte array value).  Refer to the \fBTcl_NumUtfChars\fR manual
 entry for more details on the UTF\-8 representation.
 .PP
+Formally, the \fBstring bytelength\fR operation returns the content of
+the \fIlength\fR field of the \fBTcl_Obj\fR structure, after calling
+\fBTcl_GetString\fR to ensure that the \fIbytes\fR field is populated.
+This is highly unlikely to be useful to Tcl scripts, as Tcl's internal
+encoding is not strict UTF\-8, but rather a modified CESU\-8 with a
+denormalized NUL (identical to that used in a number of places by
+Java's serialization mechanism) to enable basic processing with
+non-Unicode-aware C functions.  As this representation should only
+ever be used by Tcl's implementation, the number of bytes used to
+store the representation is of very low value (except to C extension
+code, which has direct access for the purpose of memory management,
+etc.)
+.PP
 \fICompatibility note:\fR it is likely that this subcommand will be
 withdrawn in a future version of Tcl. It is better to use the
 \fBencoding convertto\fR command to convert a string to a known
 encoding and then apply \fBstring length\fR to that.
+.PP
+.CS
+\fBstring length\fR [encoding convertto utf-8 $theString]
+.CE
 .RE
 .TP
 \fBstring wordend \fIstring charIndex\fR
diff --git a/doc/tclvars.n b/doc/tclvars.n
index 2fec222..9d7a4ce 100644
--- a/doc/tclvars.n
+++ b/doc/tclvars.n
@@ -10,7 +10,7 @@
 .BS
 '\" Note:  do not modify the .SH NAME line immediately below!
 .SH NAME
-argc, argv, argv0, auto_path, env, errorCode, errorInfo, tcl_interactive, tcl_library, tcl_nonwordchars, tcl_patchLevel, tcl_pkgPath, tcl_platform, tcl_precision, tcl_rcFileName, tcl_traceCompile, tcl_traceEval, tcl_wordchars, tcl_version \- Variables used by Tcl
+argc, argv, argv0, auto_path, env, errorCode, errorInfo, tcl_interactive, tcl_library, tcl_nonwordchars, tcl_patchLevel, tcl_pkgPath, tcl_platform, tcl_precision, tcl_rcFileName, tcl_traceCompile, tcl_traceExec, tcl_wordchars, tcl_version \- Variables used by Tcl
 .BE
 .SH DESCRIPTION
 .PP
diff --git a/generic/tcl.h b/generic/tcl.h
index ab54078..b93b3ac 100644
--- a/generic/tcl.h
+++ b/generic/tcl.h
@@ -67,15 +67,12 @@ extern "C" {
  * We use this method because there is no autoconf equivalent.
  */
 
-#ifndef __WIN32__
-#   if defined(_WIN32) || defined(WIN32) || defined(__MINGW32__) || defined(__BORLANDC__) || (defined(__WATCOMC__) && defined(__WINDOWS_386__))
+#ifdef _WIN32
+#   ifndef __WIN32__
 #	define __WIN32__
-#	ifndef WIN32
-#	    define WIN32
-#	endif
-#	ifndef _WIN32
-#	    define _WIN32
-#	endif
+#   endif
+#   ifndef WIN32
+#	define WIN32
 #   endif
 #endif
 
@@ -83,11 +80,11 @@ extern "C" {
  * STRICT: See MSDN Article Q83456
  */
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #   ifndef STRICT
 #	define STRICT
 #   endif
-#endif /* __WIN32__ */
+#endif /* _WIN32 */
 
 /*
  * Utility macros: STRINGIFY takes an argument and wraps it in "" (double
@@ -191,7 +188,7 @@ extern "C" {
  *       MSVCRT.
  */
 
-#if (defined(__WIN32__) && (defined(_MSC_VER) || (__BORLANDC__ >= 0x0550) || defined(__LCC__) || defined(__WATCOMC__) || (defined(__GNUC__) && defined(__declspec))))
+#if (defined(_WIN32) && (defined(_MSC_VER) || (defined(__BORLANDC__) && (__BORLANDC__ >= 0x0550)) || defined(__LCC__) || defined(__WATCOMC__) || (defined(__GNUC__) && defined(__declspec))))
 #   define HAVE_DECLSPEC 1
 #   ifdef STATIC_BUILD
 #       define DLLIMPORT
@@ -315,14 +312,14 @@ extern "C" {
  * VOID. This block is skipped under Cygwin and Mingw.
  */
 
-#if defined(__WIN32__) && !defined(HAVE_WINNT_IGNORE_VOID)
+#if defined(_WIN32) && !defined(HAVE_WINNT_IGNORE_VOID)
 #ifndef VOID
 #define VOID void
 typedef char CHAR;
 typedef short SHORT;
 typedef long LONG;
 #endif
-#endif /* __WIN32__ && !HAVE_WINNT_IGNORE_VOID */
+#endif /* _WIN32 && !HAVE_WINNT_IGNORE_VOID */
 
 /*
  * Macro to use instead of "void" for arguments that must have type "void *"
@@ -390,7 +387,7 @@ typedef long LONG;
  */
 
 #if !defined(TCL_WIDE_INT_TYPE)&&!defined(TCL_WIDE_INT_IS_LONG)
-#   if defined(__WIN32__)
+#   if defined(_WIN32)
 #      define TCL_WIDE_INT_TYPE __int64
 #      ifdef __BORLANDC__
 #         define TCL_LL_MODIFIER	"L"
@@ -400,7 +397,7 @@ typedef long LONG;
 #   elif defined(__GNUC__)
 #      define TCL_WIDE_INT_TYPE long long
 #      define TCL_LL_MODIFIER	"ll"
-#   else /* ! __WIN32__ && ! __GNUC__ */
+#   else /* ! _WIN32 && ! __GNUC__ */
 /*
  * Don't know what platform it is and configure hasn't discovered what is
  * going on for us. Try to guess...
@@ -415,7 +412,7 @@ typedef long LONG;
 #	     define TCL_WIDE_INT_TYPE long long
 #         endif
 #      endif /* NO_LIMITS_H */
-#   endif /* __WIN32__ */
+#   endif /* _WIN32 */
 #endif /* !TCL_WIDE_INT_TYPE & !TCL_WIDE_INT_IS_LONG */
 #ifdef TCL_WIDE_INT_IS_LONG
 #   undef TCL_WIDE_INT_TYPE
@@ -447,7 +444,7 @@ typedef unsigned TCL_WIDE_INT_TYPE	Tcl_WideUInt;
 #   define Tcl_DoubleAsWide(val)	((Tcl_WideInt)((double)(val)))
 #endif /* TCL_WIDE_INT_IS_LONG */
 
-#if defined(__WIN32__)
+#if defined(_WIN32)
 #   ifdef __BORLANDC__
 	typedef struct stati64 Tcl_StatBuf;
 #   elif defined(_WIN64)
@@ -458,7 +455,7 @@ typedef unsigned TCL_WIDE_INT_TYPE	Tcl_WideUInt;
 	typedef struct _stat32i64 Tcl_StatBuf;
 #   endif /* _MSC_VER < 1400 */
 #elif defined(__CYGWIN__)
-    typedef struct _stat32i64 {
+    typedef struct {
 	dev_t st_dev;
 	unsigned short st_ino;
 	unsigned short st_mode;
@@ -562,7 +559,7 @@ typedef struct Tcl_ZLibStream_ *Tcl_ZlibStream;
  * will be called as the main fuction of the new thread created by that call.
  */
 
-#if defined __WIN32__
+#if defined _WIN32
 typedef unsigned (__stdcall Tcl_ThreadCreateProc) (ClientData clientData);
 #else
 typedef void (Tcl_ThreadCreateProc) (ClientData clientData);
@@ -574,7 +571,7 @@ typedef void (Tcl_ThreadCreateProc) (ClientData clientData);
  * in generic/tclThreadTest.c for it's usage.
  */
 
-#if defined __WIN32__
+#if defined _WIN32
 #   define Tcl_ThreadCreateType		unsigned __stdcall
 #   define TCL_THREAD_CREATE_RETURN	return 0
 #else
diff --git a/generic/tclAssembly.c b/generic/tclAssembly.c
index fc51457..d1866c8 100644
--- a/generic/tclAssembly.c
+++ b/generic/tclAssembly.c
@@ -26,6 +26,7 @@
  *-   jumpTable testing
  *-   syntax (?)
  *-   returnCodeBranch
+ *-   tclooNext, tclooNextClass
  */
 
 #include "tclInt.h"
@@ -49,7 +50,7 @@ typedef enum BasicBlockCatchState {
     BBCS_UNKNOWN = 0,		/* Catch context has not yet been identified */
     BBCS_NONE,			/* Block is outside of any catch */
     BBCS_INCATCH,		/* Block is within a catch context */
-    BBCS_CAUGHT,		/* Block is within a catch context and
+    BBCS_CAUGHT 		/* Block is within a catch context and
 				 * may be executed after an exception fires */
 } BasicBlockCatchState;
 
@@ -120,7 +121,7 @@ enum BasicBlockFlags {
 				 * marking it as the start of a 'catch'
 				 * sequence. The 'jumpTarget' is the exception
 				 * exit from the catch block. */
-    BB_ENDCATCH = (1 << 5),	/* Block ends with an 'endCatch' instruction,
+    BB_ENDCATCH = (1 << 5)	/* Block ends with an 'endCatch' instruction,
 				 * unwinding the catch from the exception
 				 * stack. */
 };
@@ -183,7 +184,7 @@ typedef enum TalInstType {
 				 * produces N */
     ASSEM_SINT1,		/* One 1-byte signed-integer operand
 				 * (INCR_STK_IMM) */
-    ASSEM_SINT4_LVT4,		/* Signed 4-byte integer operand followed by
+    ASSEM_SINT4_LVT4		/* Signed 4-byte integer operand followed by
 				 * LVT entry.  Fixed arity */
 } TalInstType;
 
@@ -246,8 +247,6 @@ static void		BBEmitInstInt4(AssemblyEnv* assemEnvPtr, int tblIdx,
 			    int opnd, int count);
 static void		BBEmitInst1or4(AssemblyEnv* assemEnvPtr, int tblIdx,
 			    int param, int count);
-static void		BBEmitInvoke1or4(AssemblyEnv* assemEnvPtr, int tblIdx,
-			    int param, int count);
 static void		BBEmitOpcode(AssemblyEnv* assemEnvPtr, int tblIdx,
 			    int count);
 static int		BuildExceptionRanges(AssemblyEnv* assemEnvPtr);
@@ -351,7 +350,8 @@ static const TalInstDesc TalInstructionTable[] = {
     {"bitnot",		ASSEM_1BYTE,	INST_BITNOT,		1,	1},
     {"bitor",		ASSEM_1BYTE,	INST_BITOR,		2,	1},
     {"bitxor",		ASSEM_1BYTE,	INST_BITXOR,		2,	1},
-    {"concat",		ASSEM_CONCAT1,	INST_CONCAT1,		INT_MIN,1},
+    {"concat",		ASSEM_CONCAT1,	INST_STR_CONCAT1,	INT_MIN,1},
+    {"concatStk",	ASSEM_LIST,	INST_CONCAT_STK,	INT_MIN,1},
     {"coroName",	ASSEM_1BYTE,	INST_COROUTINE_NAME,	0,	1},
     {"currentNamespace",ASSEM_1BYTE,	INST_NS_CURRENT,	0,	1},
     {"dictAppend",	ASSEM_LVT4,	INST_DICT_APPEND,	2,	1},
@@ -438,6 +438,8 @@ static const TalInstDesc TalInstructionTable[] = {
     {"nop",		ASSEM_1BYTE,	INST_NOP,		0,	0},
     {"not",		ASSEM_1BYTE,	INST_LNOT,		1,	1},
     {"nsupvar",		ASSEM_LVT4,	INST_NSUPVAR,		2,	1},
+    {"numericType",	ASSEM_1BYTE,	INST_NUM_TYPE,		1,	1},
+    {"originCmd",	ASSEM_1BYTE,	INST_ORIGIN_COMMAND,	1,	1},
     {"over",		ASSEM_OVER,	INST_OVER,		INT_MIN,-1-1},
     {"pop",		ASSEM_1BYTE,	INST_POP,		1,	0},
     {"pushReturnCode",	ASSEM_1BYTE,	INST_PUSH_RETURN_CODE,	0,	1},
@@ -454,7 +456,11 @@ static const TalInstDesc TalInstructionTable[] = {
 					 | INST_STORE_ARRAY4),	2,	1},
     {"storeArrayStk",	ASSEM_1BYTE,	INST_STORE_ARRAY_STK,	3,	1},
     {"storeStk",	ASSEM_1BYTE,	INST_STORE_STK,		2,	1},
+    {"strcaseLower",	ASSEM_1BYTE,	INST_STR_LOWER,		1,	1},
+    {"strcaseTitle",	ASSEM_1BYTE,	INST_STR_TITLE,		1,	1},
+    {"strcaseUpper",	ASSEM_1BYTE,	INST_STR_UPPER,		1,	1},
     {"strcmp",		ASSEM_1BYTE,	INST_STR_CMP,		2,	1},
+    {"strcat",		ASSEM_CONCAT1,	INST_STR_CONCAT1,	INT_MIN,1},
     {"streq",		ASSEM_1BYTE,	INST_STR_EQ,		2,	1},
     {"strfind",		ASSEM_1BYTE,	INST_STR_FIND,		2,	1},
     {"strindex",	ASSEM_1BYTE,	INST_STR_INDEX,		2,	1},
@@ -463,12 +469,17 @@ static const TalInstDesc TalInstructionTable[] = {
     {"strmatch",	ASSEM_BOOL,	INST_STR_MATCH,		2,	1},
     {"strneq",		ASSEM_1BYTE,	INST_STR_NEQ,		2,	1},
     {"strrange",	ASSEM_1BYTE,	INST_STR_RANGE,		3,	1},
+    {"strreplace",	ASSEM_1BYTE,	INST_STR_REPLACE,	4,	1},
     {"strrfind",	ASSEM_1BYTE,	INST_STR_FIND_LAST,	2,	1},
+    {"strtrim",		ASSEM_1BYTE,	INST_STR_TRIM,		2,	1},
+    {"strtrimLeft",	ASSEM_1BYTE,	INST_STR_TRIM_LEFT,	2,	1},
+    {"strtrimRight",	ASSEM_1BYTE,	INST_STR_TRIM_RIGHT,	2,	1},
     {"sub",		ASSEM_1BYTE,	INST_SUB,		2,	1},
     {"tclooClass",	ASSEM_1BYTE,	INST_TCLOO_CLASS,	1,	1},
     {"tclooIsObject",	ASSEM_1BYTE,	INST_TCLOO_IS_OBJECT,	1,	1},
     {"tclooNamespace",	ASSEM_1BYTE,	INST_TCLOO_NS,		1,	1},
     {"tclooSelf",	ASSEM_1BYTE,	INST_TCLOO_SELF,	0,	1},
+    {"tryCvtToBoolean",	ASSEM_1BYTE,	INST_TRY_CVT_TO_BOOLEAN,1,	2},
     {"tryCvtToNumeric",	ASSEM_1BYTE,	INST_TRY_CVT_TO_NUMERIC,1,	1},
     {"uminus",		ASSEM_1BYTE,	INST_UMINUS,		1,	1},
     {"unset",		ASSEM_BOOL_LVT4,INST_UNSET_SCALAR,	0,	0},
@@ -495,6 +506,7 @@ static const unsigned char NonThrowingByteCodes[] = {
     INST_PUSH1, INST_PUSH4, INST_POP, INST_DUP,			/* 1-4 */
     INST_JUMP1, INST_JUMP4,					/* 34-35 */
     INST_END_CATCH, INST_PUSH_RESULT, INST_PUSH_RETURN_CODE,	/* 70-72 */
+    INST_LIST,							/* 79 */
     INST_OVER,							/* 95 */
     INST_PUSH_RETURN_OPTIONS,					/* 108 */
     INST_REVERSE,						/* 126 */
@@ -504,7 +516,11 @@ static const unsigned char NonThrowingByteCodes[] = {
     INST_COROUTINE_NAME,					/* 149 */
     INST_NS_CURRENT,						/* 151 */
     INST_INFO_LEVEL_NUM,					/* 152 */
-    INST_RESOLVE_COMMAND					/* 154 */
+    INST_RESOLVE_COMMAND,					/* 154 */
+    INST_STR_TRIM, INST_STR_TRIM_LEFT, INST_STR_TRIM_RIGHT,	/* 166-168 */
+    INST_CONCAT_STK,						/* 169 */
+    INST_STR_UPPER, INST_STR_LOWER, INST_STR_TITLE,		/* 170-172 */
+    INST_NUM_TYPE						/* 180 */
 };
 
 /*
@@ -681,13 +697,10 @@ BBEmitInstInt4(
 /*
  *-----------------------------------------------------------------------------
  *
- * BBEmitInst1or4, BBEmitInvoke1or4 --
+ * BBEmitInst1or4 --
  *
  *	Emits a 1- or 4-byte operation according to the magnitude of the
- *	operand. The Invoke variant generates wrapping stack-balance
- *	management if necessary (which is not normally required in assembled
- *	code, as loop exception ranges, expansions, breaks and continues can't
- *	be issued currently).
+ *	operand.
  *
  *-----------------------------------------------------------------------------
  */
@@ -719,29 +732,6 @@ BBEmitInst1or4(
     TclUpdateAtCmdStart(op, envPtr);
     BBUpdateStackReqs(bbPtr, tblIdx, count);
 }
-
-static void
-BBEmitInvoke1or4(
-    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
-    int tblIdx,			/* Index in TalInstructionTable of op */
-    int param,			/* Variable-length parameter */
-    int count)			/* Arity if variadic */
-{
-    CompileEnv* envPtr = assemEnvPtr->envPtr;
-				/* Compilation environment */
-    BasicBlock* bbPtr = assemEnvPtr->curr_bb;
-				/* Current basic block */
-    int op = TalInstructionTable[tblIdx].tclInstCode;
-
-    if (param <= 0xff) {
-	op >>= 8;
-    } else {
-	op &= 0xff;
-    }
-    TclEmitInvoke(envPtr, op, param);
-    TclUpdateAtCmdStart(op, envPtr);
-    BBUpdateStackReqs(bbPtr, tblIdx, count);
-}
 
 /*
  *-----------------------------------------------------------------------------
@@ -1478,7 +1468,7 @@ AssembleOneLine(
 	    goto cleanup;
 	}
 
-	BBEmitInvoke1or4(assemEnvPtr, tblIdx, opnd, opnd);
+	BBEmitInst1or4(assemEnvPtr, tblIdx, opnd, opnd);
 	break;
 
     case ASSEM_JUMP:
diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index a41351e..2a334c4 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -211,7 +211,7 @@ static const CmdInfo builtInCmds[] = {
     {"case",		Tcl_CaseObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
 #endif
     {"catch",		Tcl_CatchObjCmd,	TclCompileCatchCmd,	TclNRCatchObjCmd,	CMD_IS_SAFE},
-    {"concat",		Tcl_ConcatObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"concat",		Tcl_ConcatObjCmd,	TclCompileConcatCmd,	NULL,	CMD_IS_SAFE},
     {"continue",	Tcl_ContinueObjCmd,	TclCompileContinueCmd,	NULL,	CMD_IS_SAFE},
     {"coroutine",	NULL,			NULL,			TclNRCoroutineObjCmd,	CMD_IS_SAFE},
     {"error",		Tcl_ErrorObjCmd,	TclCompileErrorCmd,	NULL,	CMD_IS_SAFE},
@@ -227,7 +227,7 @@ static const CmdInfo builtInCmds[] = {
     {"lappend",		Tcl_LappendObjCmd,	TclCompileLappendCmd,	NULL,	CMD_IS_SAFE},
     {"lassign",		Tcl_LassignObjCmd,	TclCompileLassignCmd,	NULL,	CMD_IS_SAFE},
     {"lindex",		Tcl_LindexObjCmd,	TclCompileLindexCmd,	NULL,	CMD_IS_SAFE},
-    {"linsert",		Tcl_LinsertObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"linsert",		Tcl_LinsertObjCmd,	TclCompileLinsertCmd,	NULL,	CMD_IS_SAFE},
     {"list",		Tcl_ListObjCmd,		TclCompileListCmd,	NULL,	CMD_IS_SAFE|CMD_COMPILES_EXPANDED},
     {"llength",		Tcl_LlengthObjCmd,	TclCompileLlengthCmd,	NULL,	CMD_IS_SAFE},
     {"lmap",		Tcl_LmapObjCmd,		TclCompileLmapCmd,	TclNRLmapCmd,	CMD_IS_SAFE},
@@ -259,7 +259,7 @@ static const CmdInfo builtInCmds[] = {
     {"variable",	Tcl_VariableObjCmd,	TclCompileVariableCmd,	NULL,	CMD_IS_SAFE},
     {"while",		Tcl_WhileObjCmd,	TclCompileWhileCmd,	TclNRWhileObjCmd,	CMD_IS_SAFE},
     {"yield",		NULL,			TclCompileYieldCmd,	TclNRYieldObjCmd,	CMD_IS_SAFE},
-    {"yieldto",		NULL,			NULL,			TclNRYieldToObjCmd,	CMD_IS_SAFE},
+    {"yieldto",		NULL,			TclCompileYieldToCmd,	TclNRYieldToObjCmd,	CMD_IS_SAFE},
 
     /*
      * Commands in the OS-interface. Note that many of these are unsafe.
@@ -526,6 +526,9 @@ Tcl_CreateInterp(void)
     iPtr->hiddenCmdTablePtr = NULL;
     iPtr->interpInfo = NULL;
 
+    TCL_CT_ASSERT(sizeof(iPtr->extra) <= sizeof(Tcl_HashTable));
+    iPtr->extra.optimizer = TclOptimizeBytecode;
+
     iPtr->numLevels = 0;
     iPtr->maxNestingDepth = MAX_NESTING_DEPTH;
     iPtr->framePtr = NULL;	/* Initialise as soon as :: is available */
@@ -2082,10 +2085,19 @@ Tcl_CreateCommand(
 	 */
 
 	cmdPtr = Tcl_GetHashValue(hPtr);
-	oldRefPtr = cmdPtr->importRefPtr;
-	cmdPtr->importRefPtr = NULL;
+	cmdPtr->refCount++;
+	if (cmdPtr->importRefPtr) {
+	    cmdPtr->flags |= CMD_REDEF_IN_PROGRESS;
+	}
 
 	Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
+
+	if (cmdPtr->flags & CMD_REDEF_IN_PROGRESS) {
+	    oldRefPtr = cmdPtr->importRefPtr;
+	    cmdPtr->importRefPtr = NULL;
+	}
+	TclCleanupCommandMacro(cmdPtr);
+
 	hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, tail, &isNew);
 	if (!isNew) {
 	    /*
@@ -2269,10 +2281,19 @@ Tcl_CreateObjCommand(
 	 * intact.
 	 */
 
-	oldRefPtr = cmdPtr->importRefPtr;
-	cmdPtr->importRefPtr = NULL;
+	cmdPtr->refCount++;
+	if (cmdPtr->importRefPtr) {
+	    cmdPtr->flags |= CMD_REDEF_IN_PROGRESS;
+	}
 
 	Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
+
+	if (cmdPtr->flags & CMD_REDEF_IN_PROGRESS) {
+	    oldRefPtr = cmdPtr->importRefPtr;
+	    cmdPtr->importRefPtr = NULL;
+	}
+	TclCleanupCommandMacro(cmdPtr);
+
 	hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, tail, &isNew);
 	if (!isNew) {
 	    /*
@@ -3114,12 +3135,13 @@ Tcl_DeleteCommandFromToken(
      * commands were created that refer back to this command. Delete these
      * imported commands now.
      */
-
-    for (refPtr = cmdPtr->importRefPtr; refPtr != NULL;
-	    refPtr = nextRefPtr) {
-	nextRefPtr = refPtr->nextPtr;
-	importCmd = (Tcl_Command) refPtr->importedCmdPtr;
-	Tcl_DeleteCommandFromToken(interp, importCmd);
+    if (!(cmdPtr->flags & CMD_REDEF_IN_PROGRESS)) {
+	for (refPtr = cmdPtr->importRefPtr; refPtr != NULL;
+		refPtr = nextRefPtr) {
+	    nextRefPtr = refPtr->nextPtr;
+	    importCmd = (Tcl_Command) refPtr->importedCmdPtr;
+	    Tcl_DeleteCommandFromToken(interp, importCmd);
+	}
     }
 
     /*
@@ -8413,8 +8435,7 @@ TclNRYieldToObjCmd(
 {
     CoroutineData *corPtr = iPtr->execEnvPtr->corPtr;
     Tcl_Obj *listPtr, *nsObjPtr;
-    Tcl_Namespace *nsPtr = (Tcl_Namespace *) iPtr->varFramePtr->nsPtr;
-    Tcl_Namespace *ns1Ptr;
+    Tcl_Namespace *nsPtr = TclGetCurrentNamespace(interp);
 
     if (objc < 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "command ?arg ...?");
@@ -8428,11 +8449,13 @@ TclNRYieldToObjCmd(
 	return TCL_ERROR;
     }
 
-    /*
-     * Add the tailcall in the caller env, then just yield.
-     *
-     * This is essentially code from TclNRTailcallObjCmd
-     */
+    if (((Namespace *) nsPtr)->flags & NS_DYING) {
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"yieldto called in deleted namespace", -1));
+        Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "YIELDTO_IN_DELETED",
+		NULL);
+        return TCL_ERROR;
+    }
 
     /*
      * Add the tailcall in the caller env, then just yield.
@@ -8441,15 +8464,9 @@ TclNRYieldToObjCmd(
      */
 
     listPtr = Tcl_NewListObj(objc, objv);
-
     nsObjPtr = Tcl_NewStringObj(nsPtr->fullName, -1);
-    if ((TCL_OK != TclGetNamespaceFromObj(interp, nsObjPtr, &ns1Ptr))
-	    || (nsPtr != ns1Ptr)) {
-	Tcl_Panic("yieldto failed to find the proper namespace");
-    }
     TclListObjSetElement(interp, listPtr, 0, nsObjPtr);
 
-
     /*
      * Add the callback in the caller's env, then instruct TEBC to yield.
      */
diff --git a/generic/tclBinary.c b/generic/tclBinary.c
index 4e977f2..981f174 100644
--- a/generic/tclBinary.c
+++ b/generic/tclBinary.c
@@ -610,9 +610,7 @@ UpdateStringOfByteArray(
  *
  *	This function appends an array of bytes to a byte array object. Note
  *	that the object *must* be unshared, and the array of bytes *must not*
- *	refer to the object being appended to.  Also the caller must have
- *	already checked that the final length of the bytearray after the
- *	append operations is complete will not overflow the int range.
+ *	refer to the object being appended to.
  *
  * Results:
  *	None.
@@ -631,6 +629,7 @@ TclAppendBytesToByteArray(
     int len)
 {
     ByteArray *byteArrayPtr;
+    int needed;
 
     if (Tcl_IsShared(objPtr)) {
 	Tcl_Panic("%s called with shared object","TclAppendBytesToByteArray");
@@ -639,64 +638,57 @@ TclAppendBytesToByteArray(
 	Tcl_Panic("%s must be called with definite number of bytes to append",
 		"TclAppendBytesToByteArray");
     }
+    if (len == 0) {
+	/* Append zero bytes is a no-op. */
+	return;
+    }
     if (objPtr->typePtr != &tclByteArrayType) {
 	SetByteArrayFromAny(NULL, objPtr);
     }
     byteArrayPtr = GET_BYTEARRAY(objPtr);
 
+    if (len > INT_MAX - byteArrayPtr->used) {
+	Tcl_Panic("max size for a Tcl value (%d bytes) exceeded", INT_MAX);
+    }
+
+    needed = byteArrayPtr->used + len;
     /*
      * If we need to, resize the allocated space in the byte array.
      */
 
-    if (byteArrayPtr->used + len > byteArrayPtr->allocated) {
-	unsigned int attempt, used = byteArrayPtr->used;
-	ByteArray *tmpByteArrayPtr = NULL;
+    if (needed > byteArrayPtr->allocated) {
+	ByteArray *ptr = NULL;
+	int attempt;
 
-	attempt = byteArrayPtr->allocated;
-	if (attempt < 1) {
-	    /*
-	     * No allocated bytes, so must be none used too. We use this
-	     * method to calculate how many bytes to allocate because we can
-	     * end up with a zero-length buffer otherwise, when doubling can
-	     * cause trouble. [Bug 3067036]
-	     */
-
-	    attempt = len + 1;
-	} else {
-	    do {
-		attempt *= 2;
-	    } while (attempt < used+len);
+	if (needed <= INT_MAX/2) {
+	    /* Try to allocate double the total space that is needed. */
+	    attempt = 2 * needed;
+	    ptr = attemptckrealloc(byteArrayPtr, BYTEARRAY_SIZE(attempt));
 	}
+	if (ptr == NULL) {
+	    /* Try to allocate double the increment that is needed (plus). */
+	    unsigned int limit = INT_MAX - needed;
+	    unsigned int extra = len + TCL_MIN_GROWTH;
+	    int growth = (int) ((extra > limit) ? limit : extra);
 
-	if (BYTEARRAY_SIZE(attempt) > BYTEARRAY_SIZE(used)) {
-	    tmpByteArrayPtr = attemptckrealloc(byteArrayPtr,
-		    BYTEARRAY_SIZE(attempt));
+	    attempt = needed + growth;
+	    ptr = attemptckrealloc(byteArrayPtr, BYTEARRAY_SIZE(attempt));
 	}
-
-	if (tmpByteArrayPtr == NULL) {
-	    attempt = used + len;
-	    if (BYTEARRAY_SIZE(attempt) < BYTEARRAY_SIZE(used)) {
-		Tcl_Panic("attempt to allocate a bigger buffer than we can handle");
-	    }
-	    tmpByteArrayPtr = ckrealloc(byteArrayPtr,
-		    BYTEARRAY_SIZE(attempt));
+	if (ptr == NULL) {
+	    /* Last chance: Try to allocate exactly what is needed. */
+	    attempt = needed;
+	    ptr = ckrealloc(byteArrayPtr, BYTEARRAY_SIZE(attempt));
 	}
-
-	byteArrayPtr = tmpByteArrayPtr;
+	byteArrayPtr = ptr;
 	byteArrayPtr->allocated = attempt;
-	byteArrayPtr->used = used;
 	SET_BYTEARRAY(objPtr, byteArrayPtr);
     }
 
-    /*
-     * Do the append if there's any point.
-     */
-
-    if (len > 0) {
+    if (bytes) {
 	memcpy(byteArrayPtr->bytes + byteArrayPtr->used, bytes, len);
-	byteArrayPtr->used += len;
-	TclInvalidateStringRep(objPtr);
     }
+    byteArrayPtr->used += len;
+    TclInvalidateStringRep(objPtr);
 }
 
 /*
diff --git a/generic/tclClock.c b/generic/tclClock.c
index 6d2976d..50d480c 100644
--- a/generic/tclClock.c
+++ b/generic/tclClock.c
@@ -19,7 +19,7 @@
  * Windows has mktime. The configurators do not check.
  */
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #define HAVE_MKTIME 1
 #endif
 
diff --git a/generic/tclCmdAH.c b/generic/tclCmdAH.c
index f90819a..d90a747 100644
--- a/generic/tclCmdAH.c
+++ b/generic/tclCmdAH.c
@@ -1590,7 +1590,7 @@ FileAttrIsOwnedCmd(
 	 * test for equivalence to the current user.
 	 */
 
-#if defined(__WIN32__) || defined(__CYGWIN__)
+#if defined(_WIN32) || defined(__CYGWIN__)
 	value = 1;
 #else
 	value = (geteuid() == buf.st_uid);
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c
index fa4ead4..41c1eb6 100644
--- a/generic/tclCmdIL.c
+++ b/generic/tclCmdIL.c
@@ -1147,41 +1147,38 @@ InfoFrameCmd(
     Tcl_Obj *const objv[])	/* Argument objects. */
 {
     Interp *iPtr = (Interp *) interp;
-    int level, topLevel, code = TCL_OK;
-    CmdFrame *runPtr, *framePtr;
+    int level, code = TCL_OK;
+    CmdFrame *framePtr, **cmdFramePtrPtr = &iPtr->cmdFramePtr;
     CoroutineData *corPtr = iPtr->execEnvPtr->corPtr;
+    int topLevel = 0;
 
     if (objc > 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "?number?");
 	return TCL_ERROR;
     }
 
-    topLevel = ((iPtr->cmdFramePtr == NULL)
-	    ? 0
-	    : iPtr->cmdFramePtr->level);
-
-    if (corPtr) {
-	/*
-	 * A coroutine: must fix the level computations AND the cmdFrame chain,
-	 * which is interrupted at the base.
-	 */
-
-	CmdFrame *lastPtr = NULL;
-
-	runPtr = iPtr->cmdFramePtr;
+    while (corPtr) {
+	while (*cmdFramePtrPtr) {
+	    topLevel++;
+	    cmdFramePtrPtr = &((*cmdFramePtrPtr)->nextPtr);
+	}
+	if (corPtr->caller.cmdFramePtr) {
+	    *cmdFramePtrPtr = corPtr->caller.cmdFramePtr;
+	}
+	corPtr = corPtr->callerEEPtr->corPtr;
+    }
+    topLevel += (*cmdFramePtrPtr)->level;
 
-	/* TODO - deal with overflow */
-	topLevel += corPtr->caller.cmdFramePtr->level;
-	while (runPtr) {
-	    runPtr->level += corPtr->caller.cmdFramePtr->level;
-	    lastPtr = runPtr;
-	    runPtr = runPtr->nextPtr;
+    if (topLevel != iPtr->cmdFramePtr->level) {
+	framePtr = iPtr->cmdFramePtr;
+	while (framePtr) {
+	    framePtr->level = topLevel--;
+	    framePtr = framePtr->nextPtr;
 	}
-	if (lastPtr) {
-	    lastPtr->nextPtr = corPtr->caller.cmdFramePtr;
-	} else {
-	    iPtr->cmdFramePtr = corPtr->caller.cmdFramePtr;
+	if (topLevel) {
+	    Tcl_Panic("Broken frame level calculation");
 	}
+	topLevel = iPtr->cmdFramePtr->level;
     }
 
     if (objc == 1) {
@@ -1231,20 +1228,27 @@ InfoFrameCmd(
     Tcl_SetObjResult(interp, TclInfoFrame(interp, framePtr));
 
   done:
-    if (corPtr) {
+    cmdFramePtrPtr = &iPtr->cmdFramePtr;
+    corPtr = iPtr->execEnvPtr->corPtr;
+    while (corPtr) {
+	CmdFrame *endPtr = corPtr->caller.cmdFramePtr;
+
+	if (endPtr) {
+	    if (*cmdFramePtrPtr == endPtr) {
+		*cmdFramePtrPtr = NULL;
+	    } else {
+		CmdFrame *runPtr = *cmdFramePtrPtr;
 
-	if (iPtr->cmdFramePtr == corPtr->caller.cmdFramePtr) {
-	    iPtr->cmdFramePtr = NULL;
-	} else {
-	    runPtr = iPtr->cmdFramePtr;
-	    while (runPtr->nextPtr != corPtr->caller.cmdFramePtr) {
-	    	runPtr->level -= corPtr->caller.cmdFramePtr->level;
-		runPtr = runPtr->nextPtr;
+		while (runPtr->nextPtr != endPtr) {
+		    runPtr->level -= endPtr->level;
+		    runPtr = runPtr->nextPtr;
+		}
+		runPtr->level = 1;
+		runPtr->nextPtr = NULL;
 	    }
-	    runPtr->level = 1;
-	    runPtr->nextPtr = NULL;
+	    cmdFramePtrPtr = &corPtr->caller.cmdFramePtr;
 	}
-
+	corPtr = corPtr->callerEEPtr->corPtr;
     }
     return code;
 }
diff --git a/generic/tclCmdMZ.c b/generic/tclCmdMZ.c
index 5087fbb..00c9f2f 100644
--- a/generic/tclCmdMZ.c
+++ b/generic/tclCmdMZ.c
@@ -18,6 +18,7 @@
 
 #include "tclInt.h"
 #include "tclRegexp.h"
+#include "tclStringTrim.h"
 
 static inline Tcl_Obj *	During(Tcl_Interp *interp, int resultCode,
 			    Tcl_Obj *oldOptions, Tcl_Obj *errorInfo);
@@ -37,32 +38,33 @@ static int		UniCharIsHexDigit(int character);
  * UTF-8 literal string containing all Unicode space characters [TIP #413]
  */
 
-#define DEFAULT_TRIM_SET \
-	"\x09\x0a\x0b\x0c\x0d " /* ASCII */\
-	"\xc0\x80" /*     nul (U+0000) */\
-	"\xc2\x85" /*     next line (U+0085) */\
-	"\xc2\xa0" /*     non-breaking space (U+00a0) */\
-	"\xe1\x9a\x80" /* ogham space mark (U+1680) */ \
-	"\xe1\xa0\x8e" /* mongolian vowel separator (U+180e) */\
-	"\xe2\x80\x80" /* en quad (U+2000) */\
-	"\xe2\x80\x81" /* em quad (U+2001) */\
-	"\xe2\x80\x82" /* en space (U+2002) */\
-	"\xe2\x80\x83" /* em space (U+2003) */\
-	"\xe2\x80\x84" /* three-per-em space (U+2004) */\
-	"\xe2\x80\x85" /* four-per-em space (U+2005) */\
-	"\xe2\x80\x86" /* six-per-em space (U+2006) */\
-	"\xe2\x80\x87" /* figure space (U+2007) */\
-	"\xe2\x80\x88" /* punctuation space (U+2008) */\
-	"\xe2\x80\x89" /* thin space (U+2009) */\
-	"\xe2\x80\x8a" /* hair space (U+200a) */\
-	"\xe2\x80\x8b" /* zero width space (U+200b) */\
-	"\xe2\x80\xa8" /* line separator (U+2028) */\
-	"\xe2\x80\xa9" /* paragraph separator (U+2029) */\
-	"\xe2\x80\xaf" /* narrow no-break space (U+202f) */\
-	"\xe2\x81\x9f" /* medium mathematical space (U+205f) */\
-	"\xe2\x81\xa0" /* word joiner (U+2060) */\
-	"\xe3\x80\x80" /* ideographic space (U+3000) */\
+const char tclDefaultTrimSet[] = 
+	"\x09\x0a\x0b\x0c\x0d " /* ASCII */
+	"\xc0\x80" /*     nul (U+0000) */
+	"\xc2\x85" /*     next line (U+0085) */
+	"\xc2\xa0" /*     non-breaking space (U+00a0) */
+	"\xe1\x9a\x80" /* ogham space mark (U+1680) */
+	"\xe1\xa0\x8e" /* mongolian vowel separator (U+180e) */
+	"\xe2\x80\x80" /* en quad (U+2000) */
+	"\xe2\x80\x81" /* em quad (U+2001) */
+	"\xe2\x80\x82" /* en space (U+2002) */
+	"\xe2\x80\x83" /* em space (U+2003) */
+	"\xe2\x80\x84" /* three-per-em space (U+2004) */
+	"\xe2\x80\x85" /* four-per-em space (U+2005) */
+	"\xe2\x80\x86" /* six-per-em space (U+2006) */
+	"\xe2\x80\x87" /* figure space (U+2007) */
+	"\xe2\x80\x88" /* punctuation space (U+2008) */
+	"\xe2\x80\x89" /* thin space (U+2009) */
+	"\xe2\x80\x8a" /* hair space (U+200a) */
+	"\xe2\x80\x8b" /* zero width space (U+200b) */
+	"\xe2\x80\xa8" /* line separator (U+2028) */
+	"\xe2\x80\xa9" /* paragraph separator (U+2029) */
+	"\xe2\x80\xaf" /* narrow no-break space (U+202f) */
+	"\xe2\x81\x9f" /* medium mathematical space (U+205f) */
+	"\xe2\x81\xa0" /* word joiner (U+2060) */
+	"\xe3\x80\x80" /* ideographic space (U+3000) */
 	"\xef\xbb\xbf" /* zero width no-break space (U+feff) */
+;
 
 /*
  *----------------------------------------------------------------------
@@ -3189,8 +3191,8 @@ StringTrimCmd(
     if (objc == 3) {
 	string2 = TclGetStringFromObj(objv[2], &length2);
     } else if (objc == 2) {
-	string2 = DEFAULT_TRIM_SET;
-	length2 = strlen(DEFAULT_TRIM_SET);
+	string2 = tclDefaultTrimSet;
+	length2 = strlen(tclDefaultTrimSet);
     } else {
 	Tcl_WrongNumArgs(interp, 1, objv, "string ?chars?");
 	return TCL_ERROR;
@@ -3237,8 +3239,8 @@ StringTrimLCmd(
     if (objc == 3) {
 	string2 = TclGetStringFromObj(objv[2], &length2);
     } else if (objc == 2) {
-	string2 = DEFAULT_TRIM_SET;
-	length2 = strlen(DEFAULT_TRIM_SET);
+	string2 = tclDefaultTrimSet;
+	length2 = strlen(tclDefaultTrimSet);
     } else {
 	Tcl_WrongNumArgs(interp, 1, objv, "string ?chars?");
 	return TCL_ERROR;
@@ -3283,8 +3285,8 @@ StringTrimRCmd(
     if (objc == 3) {
 	string2 = TclGetStringFromObj(objv[2], &length2);
     } else if (objc == 2) {
-	string2 = DEFAULT_TRIM_SET;
-	length2 = strlen(DEFAULT_TRIM_SET);
+	string2 = tclDefaultTrimSet;
+	length2 = strlen(tclDefaultTrimSet);
     } else {
 	Tcl_WrongNumArgs(interp, 1, objv, "string ?chars?");
 	return TCL_ERROR;
@@ -3330,21 +3332,21 @@ TclInitStringCmd(
 	{"equal",	StringEqualCmd,	TclCompileStringEqualCmd, NULL, NULL, 0},
 	{"first",	StringFirstCmd,	TclCompileStringFirstCmd, NULL, NULL, 0},
 	{"index",	StringIndexCmd,	TclCompileStringIndexCmd, NULL, NULL, 0},
-	{"is",		StringIsCmd,	NULL, NULL, NULL, 0},
+	{"is",		StringIsCmd,	TclCompileStringIsCmd, NULL, NULL, 0},
 	{"last",	StringLastCmd,	TclCompileStringLastCmd, NULL, NULL, 0},
 	{"length",	StringLenCmd,	TclCompileStringLenCmd, NULL, NULL, 0},
 	{"map",		StringMapCmd,	TclCompileStringMapCmd, NULL, NULL, 0},
 	{"match",	StringMatchCmd,	TclCompileStringMatchCmd, NULL, NULL, 0},
 	{"range",	StringRangeCmd,	TclCompileStringRangeCmd, NULL, NULL, 0},
 	{"repeat",	StringReptCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},
-	{"replace",	StringRplcCmd,	NULL, NULL, NULL, 0},
+	{"replace",	StringRplcCmd,	TclCompileStringReplaceCmd, NULL, NULL, 0},
 	{"reverse",	StringRevCmd,	TclCompileBasic1ArgCmd, NULL, NULL, 0},
-	{"tolower",	StringLowerCmd,	TclCompileBasic1To3ArgCmd, NULL, NULL, 0},
-	{"toupper",	StringUpperCmd,	TclCompileBasic1To3ArgCmd, NULL, NULL, 0},
-	{"totitle",	StringTitleCmd,	TclCompileBasic1To3ArgCmd, NULL, NULL, 0},
-	{"trim",	StringTrimCmd,	TclCompileBasic1Or2ArgCmd, NULL, NULL, 0},
-	{"trimleft",	StringTrimLCmd,	TclCompileBasic1Or2ArgCmd, NULL, NULL, 0},
-	{"trimright",	StringTrimRCmd,	TclCompileBasic1Or2ArgCmd, NULL, NULL, 0},
+	{"tolower",	StringLowerCmd,	TclCompileStringToLowerCmd, NULL, NULL, 0},
+	{"toupper",	StringUpperCmd,	TclCompileStringToUpperCmd, NULL, NULL, 0},
+	{"totitle",	StringTitleCmd,	TclCompileStringToTitleCmd, NULL, NULL, 0},
+	{"trim",	StringTrimCmd,	TclCompileStringTrimCmd, NULL, NULL, 0},
+	{"trimleft",	StringTrimLCmd,	TclCompileStringTrimLCmd, NULL, NULL, 0},
+	{"trimright",	StringTrimRCmd,	TclCompileStringTrimRCmd, NULL, NULL, 0},
 	{"wordend",	StringEndCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},
 	{"wordstart",	StringStartCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},
 	{NULL, NULL, NULL, NULL, NULL, 0}
diff --git a/generic/tclCompCmds.c b/generic/tclCompCmds.c
index 9c43bfe..d1d7a80 100644
--- a/generic/tclCompCmds.c
+++ b/generic/tclCompCmds.c
@@ -31,6 +31,9 @@ static void		FreeForeachInfo(ClientData clientData);
 static void		PrintForeachInfo(ClientData clientData,
 			    Tcl_Obj *appendObj, ByteCode *codePtr,
 			    unsigned int pcOffset);
+static void		PrintNewForeachInfo(ClientData clientData,
+			    Tcl_Obj *appendObj, ByteCode *codePtr,
+			    unsigned int pcOffset);
 static int		CompileEachloopCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    CompileEnv *envPtr, int collect);
@@ -49,6 +52,13 @@ const AuxDataType tclForeachInfoType = {
     PrintForeachInfo		/* printProc */
 };
 
+const AuxDataType tclNewForeachInfoType = {
+    "NewForeachInfo",		/* name */
+    DupForeachInfo,		/* dupProc */
+    FreeForeachInfo,		/* freeProc */
+    PrintNewForeachInfo		/* printProc */
+};
+
 const AuxDataType tclDictUpdateInfoType = {
     "DictUpdateInfo",		/* name */
     DupDictUpdateInfo,		/* dupProc */
@@ -245,8 +255,8 @@ TclCompileArraySetCmd(
     Tcl_Token *varTokenPtr, *dataTokenPtr;
     int isScalar, localIndex, code = TCL_OK;
     int isDataLiteral, isDataValid, isDataEven, len;
-    int dataVar, iterVar, keyVar, valVar, infoIndex;
-    int back, fwd, offsetBack, offsetFwd;
+    int keyVar, valVar, infoIndex;
+    int fwd, offsetBack, offsetFwd;
     Tcl_Obj *literalObj;
     ForeachInfo *infoPtr;
 
@@ -268,7 +278,7 @@ TclCompileArraySetCmd(
 
     if (isDataValid && !isDataEven) {
 	PushStringLiteral(envPtr, "list must have an even number of elements");
-	PushStringLiteral(envPtr, "-errorCode {TCL ARGUMENT FORMAT}");
+	PushStringLiteral(envPtr, "-errorcode {TCL ARGUMENT FORMAT}");
 	TclEmitInstInt4(INST_RETURN_IMM, TCL_ERROR,		envPtr);
 	TclEmitInt4(		0,				envPtr);
 	goto done;
@@ -290,6 +300,7 @@ TclCompileArraySetCmd(
 	code = TCL_ERROR;
 	goto done;
     }
+
     /*
      * Special case: literal empty value argument is just an "ensure array"
      * operation.
@@ -314,20 +325,29 @@ TclCompileArraySetCmd(
 	goto done;
     }
 
+    if (localIndex < 0) {
+	/*
+	 * a non-local variable: upvar from a local one! This consumes the
+	 * variable name that was left at stacktop.
+	 */
+	
+	localIndex = AnonymousLocal(envPtr);
+	PushStringLiteral(envPtr, "0");
+	TclEmitInstInt4(INST_REVERSE, 2,        		envPtr);
+	TclEmitInstInt4(INST_UPVAR, localIndex, 		envPtr);
+	TclEmitOpcode(INST_POP,          			envPtr);
+    }
+    
     /*
      * Prepare for the internal foreach.
      */
 
-    dataVar = AnonymousLocal(envPtr);
-    iterVar = AnonymousLocal(envPtr);
     keyVar = AnonymousLocal(envPtr);
     valVar = AnonymousLocal(envPtr);
 
-    infoPtr = ckalloc(sizeof(ForeachInfo) + sizeof(ForeachVarList *));
+    infoPtr = ckalloc(sizeof(ForeachInfo));
     infoPtr->numLists = 1;
-    infoPtr->firstValueTemp = dataVar;
-    infoPtr->loopCtTemp = iterVar;
-    infoPtr->varLists[0] = ckalloc(sizeof(ForeachVarList) * 2*sizeof(int));
+    infoPtr->varLists[0] = ckalloc(sizeof(ForeachVarList) + sizeof(int));
     infoPtr->varLists[0]->numVars = 2;
     infoPtr->varLists[0]->varIndexes[0] = keyVar;
     infoPtr->varLists[0]->varIndexes[1] = valVar;
@@ -353,61 +373,30 @@ TclCompileArraySetCmd(
 	offsetFwd = CurrentOffset(envPtr);
 	TclEmitInstInt1(INST_JUMP_FALSE1, 0,			envPtr);
 	PushStringLiteral(envPtr, "list must have an even number of elements");
-	PushStringLiteral(envPtr, "-errorCode {TCL ARGUMENT FORMAT}");
+	PushStringLiteral(envPtr, "-errorcode {TCL ARGUMENT FORMAT}");
 	TclEmitInstInt4(INST_RETURN_IMM, TCL_ERROR,		envPtr);
 	TclEmitInt4(		0,				envPtr);
 	TclAdjustStackDepth(-1, envPtr);
 	fwd = CurrentOffset(envPtr) - offsetFwd;
 	TclStoreInt1AtPtr(fwd, envPtr->codeStart+offsetFwd+1);
     }
-    Emit14Inst(		INST_STORE_SCALAR, dataVar,		envPtr);
-    TclEmitOpcode(	INST_POP,				envPtr);
 
-    if (localIndex >= 0) {
-	TclEmitInstInt4(INST_ARRAY_EXISTS_IMM, localIndex,	envPtr);
-	TclEmitInstInt1(INST_JUMP_TRUE1, 7,			envPtr);
-	TclEmitInstInt4(INST_ARRAY_MAKE_IMM, localIndex,	envPtr);
-	TclEmitInstInt4(INST_FOREACH_START4, infoIndex,		envPtr);
-	offsetBack = CurrentOffset(envPtr);
-	TclEmitInstInt4(INST_FOREACH_STEP4, infoIndex,		envPtr);
-	offsetFwd = CurrentOffset(envPtr);
-	TclEmitInstInt1(INST_JUMP_FALSE1, 0,			envPtr);
-	Emit14Inst(	INST_LOAD_SCALAR, keyVar,		envPtr);
-	Emit14Inst(	INST_LOAD_SCALAR, valVar,		envPtr);
-	Emit14Inst(	INST_STORE_ARRAY, localIndex,		envPtr);
-	TclEmitOpcode(	INST_POP,				envPtr);
-	back = offsetBack - CurrentOffset(envPtr);
-	TclEmitInstInt1(INST_JUMP1, back,			envPtr);
-	fwd = CurrentOffset(envPtr) - offsetFwd;
-	TclStoreInt1AtPtr(fwd, envPtr->codeStart+offsetFwd+1);
-    } else {
-	TclEmitOpcode(	INST_DUP,				envPtr);
-	TclEmitOpcode(	INST_ARRAY_EXISTS_STK,			envPtr);
-	TclEmitInstInt1(INST_JUMP_TRUE1, 4,			envPtr);
-	TclEmitOpcode(	INST_DUP,				envPtr);
-	TclEmitOpcode(	INST_ARRAY_MAKE_STK,			envPtr);
-	TclEmitInstInt4(INST_FOREACH_START4, infoIndex,		envPtr);
-	offsetBack = CurrentOffset(envPtr);
-	TclEmitInstInt4(INST_FOREACH_STEP4, infoIndex,		envPtr);
-	offsetFwd = CurrentOffset(envPtr);
-	TclEmitInstInt1(INST_JUMP_FALSE1, 0,			envPtr);
-	TclEmitOpcode(	INST_DUP,				envPtr);
-	Emit14Inst(	INST_LOAD_SCALAR, keyVar,		envPtr);
-	Emit14Inst(	INST_LOAD_SCALAR, valVar,		envPtr);
-	TclEmitOpcode(	INST_STORE_ARRAY_STK,			envPtr);
-	TclEmitOpcode(	INST_POP,				envPtr);
-	back = offsetBack - CurrentOffset(envPtr);
-	TclEmitInstInt1(INST_JUMP1, back,			envPtr);
-	fwd = CurrentOffset(envPtr) - offsetFwd;
-	TclStoreInt1AtPtr(fwd, envPtr->codeStart+offsetFwd+1);
-	TclEmitOpcode(	INST_POP,				envPtr);
-    }
-    if (!isDataLiteral) {
-	TclEmitInstInt1(INST_UNSET_SCALAR, 0,			envPtr);
-	TclEmitInt4(		dataVar,			envPtr);
-    }
+    TclEmitInstInt4(INST_ARRAY_EXISTS_IMM, localIndex,	envPtr);
+    TclEmitInstInt1(INST_JUMP_TRUE1, 7,			envPtr);
+    TclEmitInstInt4(INST_ARRAY_MAKE_IMM, localIndex,	envPtr);
+    TclEmitInstInt4(INST_FOREACH_START, infoIndex,	envPtr);
+    offsetBack = CurrentOffset(envPtr);
+    Emit14Inst(	INST_LOAD_SCALAR, keyVar,		envPtr);
+    Emit14Inst(	INST_LOAD_SCALAR, valVar,		envPtr);
+    Emit14Inst(	INST_STORE_ARRAY, localIndex,		envPtr);
+    TclEmitOpcode(	INST_POP,			envPtr);
+    infoPtr->loopCtTemp = offsetBack - CurrentOffset(envPtr); /*misuse */
+    TclEmitOpcode( INST_FOREACH_STEP,			envPtr);
+    TclEmitOpcode( INST_FOREACH_END,			envPtr);
+    TclAdjustStackDepth(-3, envPtr);
     PushStringLiteral(envPtr,	"");
-  done:
+
+    done:
     Tcl_DecrRefCount(literalObj);
     return code;
 }
@@ -500,17 +489,14 @@ TclCompileBreakCmd(
 
 	TclCleanupStackForBreakContinue(envPtr, auxPtr);
 	TclAddLoopBreakFixup(envPtr, auxPtr);
-	TclAdjustStackDepth(1, envPtr);
     } else {
 	/*
 	 * Emit a real break.
 	 */
 
-	PushStringLiteral(envPtr, "");
-	TclEmitOpcode(INST_DUP, envPtr);
-	TclEmitInstInt4(INST_RETURN_IMM, TCL_BREAK, envPtr);
-	TclEmitInt4(0, envPtr);
+	TclEmitOpcode(INST_BREAK, envPtr);
     }
+    TclAdjustStackDepth(1, envPtr);
 
     return TCL_OK;
 }
@@ -544,9 +530,10 @@ TclCompileCatchCmd(
 {
     JumpFixup jumpFixup;
     Tcl_Token *cmdTokenPtr, *resultNameTokenPtr, *optsNameTokenPtr;
-    int resultIndex, optsIndex, range;
+    int resultIndex, optsIndex, range, dropScript = 0;
     DefineLineInformation;	/* TIP #280 */
-
+    int depth = TclGetStackDepth(envPtr);
+    
     /*
      * If syntax does not match what we expect for [catch], do not compile.
      * Let runtime checks determine if syntax has changed.
@@ -593,11 +580,7 @@ TclCompileCatchCmd(
     /*
      * We will compile the catch command. Declare the exception range that it
      * uses.
-     */
-
-    range = TclCreateExceptRange(CATCH_EXCEPTION_RANGE, envPtr);
-
-    /*
+     *
      * If the body is a simple word, compile a BEGIN_CATCH instruction,
      * followed by the instructions to eval the body.
      * Otherwise, compile instructions to substitute the body text before
@@ -610,6 +593,7 @@ TclCompileCatchCmd(
      * begin by undeflowing the stack below the mark set by BEGIN_CATCH4.
      */
 
+    range = TclCreateExceptRange(CATCH_EXCEPTION_RANGE, envPtr);
     if (cmdTokenPtr->type == TCL_TOKEN_SIMPLE_WORD) {
 	TclEmitInstInt4(	INST_BEGIN_CATCH4, range,	envPtr);
 	ExceptionRangeStarts(envPtr, range);
@@ -621,70 +605,50 @@ TclCompileCatchCmd(
 	ExceptionRangeStarts(envPtr, range);
 	TclEmitOpcode(		INST_DUP,			envPtr);
 	TclEmitInvoke(envPtr,	INST_EVAL_STK);
-    }
-    /* Stack at this point:
-     *    nonsimple:  script <mark> result
-     *    simple:            <mark> result
-     */
-
-    if (resultIndex == -1) {
-	/*
-	 * Special case when neither result nor options are being saved. In
-	 * that case, we can skip quite a bit of the command epilogue; all we
-	 * have to do is drop the result and push the return code (and, of
-	 * course, finish the catch context).
-	 */
-
+	/* drop the script */
+	dropScript = 1;
+	TclEmitInstInt4(	INST_REVERSE, 2,		envPtr);
 	TclEmitOpcode(		INST_POP,			envPtr);
-	PushStringLiteral(envPtr, "0");
-	TclEmitInstInt1(	INST_JUMP1, 3,			envPtr);
-	TclAdjustStackDepth(-1, envPtr);
-	ExceptionRangeTarget(envPtr, range, catchOffset);
-	TclEmitOpcode(		INST_PUSH_RETURN_CODE,		envPtr);
-	ExceptionRangeEnds(envPtr, range);
-	TclEmitOpcode(		INST_END_CATCH,			envPtr);
-
-	/*
-	 * Stack at this point:
-	 *    nonsimple:  script <mark> returnCode
-	 *    simple:            <mark> returnCode
-	 */
-
-	goto dropScriptAtEnd;
     }
+    ExceptionRangeEnds(envPtr, range);
 
+    
     /*
      * Emit the "no errors" epilogue: push "0" (TCL_OK) as the catch result,
      * and jump around the "error case" code.
      */
 
+    TclCheckStackDepth(depth+1, envPtr);
     PushStringLiteral(envPtr, "0");
     TclEmitForwardJump(envPtr, TCL_UNCONDITIONAL_JUMP, &jumpFixup);
-    /* Stack at this point: ?script? <mark> result TCL_OK */
 
     /* 
      * Emit the "error case" epilogue. Push the interpreter result and the
      * return code.
      */
 
-    TclAdjustStackDepth(-2, envPtr);
     ExceptionRangeTarget(envPtr, range, catchOffset);
-    /* Stack at this point:  ?script? */
+    TclSetStackDepth(depth + dropScript, envPtr);
+    
+    if (dropScript) {
+	TclEmitOpcode(		INST_POP,			envPtr);
+    }
+
+
+    /* Stack at this point is empty */
     TclEmitOpcode(		INST_PUSH_RESULT,		envPtr);
     TclEmitOpcode(		INST_PUSH_RETURN_CODE,		envPtr);
 
-    /*
-     * Update the target of the jump after the "no errors" code. 
-     */
+    /* Stack at this point on both branches: result returnCode */
 
-    /* Stack at this point: ?script? result returnCode */
     if (TclFixupForwardJumpToHere(envPtr, &jumpFixup, 127)) {
 	Tcl_Panic("TclCompileCatchCmd: bad jump distance %d",
 		(int)(CurrentOffset(envPtr) - jumpFixup.codeOffset));
     }
 
     /*
-     * Push the return options if the caller wants them.
+     * Push the return options if the caller wants them. This needs to happen
+     * before INST_END_CATCH
      */
 
     if (optsIndex != -1) {
@@ -695,53 +659,118 @@ TclCompileCatchCmd(
      * End the catch
      */
 
-    ExceptionRangeEnds(envPtr, range);
     TclEmitOpcode(		INST_END_CATCH,			envPtr);
 
     /*
-     * At this point, the top of the stack is inconveniently ordered:
-     *		?script? result returnCode ?returnOptions?
-     * Reverse the stack to bring the result to the top.
+     * Save the result and return options if the caller wants them. This needs
+     * to happen after INST_END_CATCH (compile-3.6/7).
      */
 
     if (optsIndex != -1) {
-	TclEmitInstInt4(	INST_REVERSE, 3,		envPtr);
-    } else {
-	TclEmitInstInt4(	INST_REVERSE, 2,		envPtr);
+	Emit14Inst(		INST_STORE_SCALAR, optsIndex,	envPtr);
+	TclEmitOpcode(		INST_POP,			envPtr);
     }
 
     /*
-     * Store the result and remove it from the stack.
+     * At this point, the top of the stack is inconveniently ordered:
+     *		result returnCode
+     * Reverse the stack to store the result.
      */
 
-    Emit14Inst(			INST_STORE_SCALAR, resultIndex,	envPtr);
-    TclEmitOpcode(		INST_POP,			envPtr);
+    TclEmitInstInt4(	INST_REVERSE, 2,		envPtr);
+    if (resultIndex != -1) {
+	Emit14Inst(	INST_STORE_SCALAR, resultIndex,	envPtr);
+    }
+    TclEmitOpcode(	INST_POP,			envPtr);
+
+    TclCheckStackDepth(depth+1, envPtr);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileConcatCmd --
+ *
+ *	Procedure called to compile the "concat" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "concat" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileConcatCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Obj *objPtr, *listObj;
+    Tcl_Token *tokenPtr;
+    int i;
+
+    /* TODO: Consider compiling expansion case. */
+    if (parsePtr->numWords == 1) {
+	/*
+	 * [concat] without arguments just pushes an empty object.
+	 */
+
+	PushStringLiteral(envPtr, "");
+	return TCL_OK;
+    }
 
     /*
-     * Stack is now ?script? ?returnOptions? returnCode.
-     * If the options dict has been requested, it is buried on the stack under
-     * the return code. Reverse the stack to bring it to the top, store it and
-     * remove it from the stack.
+     * Test if all arguments are compile-time known. If they are, we can
+     * implement with a simple push.
      */
 
-    if (optsIndex != -1) {
-	TclEmitInstInt4(	INST_REVERSE, 2,		envPtr);
-	Emit14Inst(		INST_STORE_SCALAR, optsIndex,	envPtr);
-	TclEmitOpcode(		INST_POP,			envPtr);
+    listObj = Tcl_NewObj();
+    for (i = 1, tokenPtr = parsePtr->tokenPtr; i < parsePtr->numWords; i++) {
+	tokenPtr = TokenAfter(tokenPtr);
+	objPtr = Tcl_NewObj();
+	if (!TclWordKnownAtCompileTime(tokenPtr, objPtr)) {
+	    Tcl_DecrRefCount(objPtr);
+	    Tcl_DecrRefCount(listObj);
+	    listObj = NULL;
+	    break;
+	}
+	(void) Tcl_ListObjAppendElement(NULL, listObj, objPtr);
     }
+    if (listObj != NULL) {
+	Tcl_Obj **objs;
+	const char *bytes;
+	int len;
 
-  dropScriptAtEnd:
+	Tcl_ListObjGetElements(NULL, listObj, &len, &objs);
+	objPtr = Tcl_ConcatObj(len, objs);
+	Tcl_DecrRefCount(listObj);
+	bytes = Tcl_GetStringFromObj(objPtr, &len);
+	PushLiteral(envPtr, bytes, len);
+	Tcl_DecrRefCount(objPtr);
+	return TCL_OK;
+    }
 
     /*
-     * Stack is now ?script? result. Get rid of the subst'ed script if it's
-     * hanging arond.
+     * General case: runtime concat.
      */
 
-    if (cmdTokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
-	TclEmitInstInt4(	INST_REVERSE, 2,		envPtr);
-	TclEmitOpcode(		INST_POP,			envPtr);
+    for (i = 1, tokenPtr = parsePtr->tokenPtr; i < parsePtr->numWords; i++) {
+	tokenPtr = TokenAfter(tokenPtr);
+	CompileWord(envPtr, tokenPtr, interp, i);
     }
 
+    TclEmitInstInt4(	INST_CONCAT_STK, i-1,		envPtr);
+
     return TCL_OK;
 }
 
@@ -796,17 +825,14 @@ TclCompileContinueCmd(
 
 	TclCleanupStackForBreakContinue(envPtr, auxPtr);
 	TclAddLoopContinueFixup(envPtr, auxPtr);
-	TclAdjustStackDepth(1, envPtr);
     } else {
 	/*
 	 * Emit a real continue.
 	 */
 
-	PushStringLiteral(envPtr, "");
-	TclEmitOpcode(INST_DUP, envPtr);
-	TclEmitInstInt4(INST_RETURN_IMM, TCL_CONTINUE, envPtr);
-	TclEmitInt4(0, envPtr);
+	TclEmitOpcode(INST_CONTINUE, envPtr);
     }
+    TclAdjustStackDepth(1, envPtr);
 
     return TCL_OK;
 }
@@ -1739,7 +1765,7 @@ TclCompileDictAppendCmd(
 	tokenPtr = TokenAfter(tokenPtr);
     }
     if (parsePtr->numWords > 4) {
-	TclEmitInstInt1(INST_CONCAT1, parsePtr->numWords-3, envPtr);
+	TclEmitInstInt1(INST_STR_CONCAT1, parsePtr->numWords-3, envPtr);
     }
 
     /*
@@ -2342,6 +2368,7 @@ TclCompileForCmd(
 
     SetLineInformation(2);
     TclCompileExprWords(interp, testTokenPtr, 1, envPtr);
+    TclClearNumConversion(envPtr);
 
     jumpDist = CurrentOffset(envPtr) - bodyCodeOffset;
     if (jumpDist > 127) {
@@ -2469,18 +2496,10 @@ CompileEachloopCmd(
     ForeachInfo *infoPtr;	/* Points to the structure describing this
 				 * foreach command. Stored in a AuxData
 				 * record in the ByteCode. */
-    int firstValueTemp;		/* Index of the first temp var in the frame
-				 * used to point to a value list. */
-    int loopCtTemp;		/* Index of temp var holding the loop's
-				 * iteration count. */
-    int collectVar = -1;	/* Index of temp var holding the result var
-				 * index. */
-
+    
     Tcl_Token *tokenPtr, *bodyTokenPtr;
-    unsigned char *jumpPc;
-    JumpFixup jumpFalseFixup;
-    int jumpBackDist, jumpBackOffset, infoIndex, range;
-    int numWords, numLists, numVars, loopIndex, tempVar, i, j, code;
+    int jumpBackOffset, infoIndex, range;
+    int numWords, numLists, numVars, loopIndex, i, j, code;
     DefineLineInformation;	/* TIP #280 */
 
     /*
@@ -2588,32 +2607,11 @@ CompileEachloopCmd(
 	loopIndex++;
     }
 
-    if (collect == TCL_EACH_COLLECT) {
-	collectVar = AnonymousLocal(envPtr);
-	if (collectVar < 0) {
-	    return TCL_ERROR;
-	}
-    }
-	    
     /*
-     * We will compile the foreach command. Reserve (numLists + 1) temporary
-     * variables:
-     *    - numLists temps to hold each value list
-     *    - 1 temp for the loop counter (index of next element in each list)
-     *
-     * At this time we don't try to reuse temporaries; if there are two
-     * nonoverlapping foreach loops, they don't share any temps.
+     * We will compile the foreach command.
      */
 
     code = TCL_OK;
-    firstValueTemp = -1;
-    for (loopIndex = 0;  loopIndex < numLists;  loopIndex++) {
-	tempVar = AnonymousLocal(envPtr);
-	if (loopIndex == 0) {
-	    firstValueTemp = tempVar;
-	}
-    }
-    loopCtTemp = AnonymousLocal(envPtr);
 
     /*
      * Create and initialize the ForeachInfo and ForeachVarList data
@@ -2622,16 +2620,14 @@ CompileEachloopCmd(
      */
 
     infoPtr = ckalloc(sizeof(ForeachInfo)
-	    + numLists * sizeof(ForeachVarList *));
+	    + (numLists - 1) * sizeof(ForeachVarList *));
     infoPtr->numLists = numLists;
-    infoPtr->firstValueTemp = firstValueTemp;
-    infoPtr->loopCtTemp = loopCtTemp;
     for (loopIndex = 0;  loopIndex < numLists;  loopIndex++) {
 	ForeachVarList *varListPtr;
 
 	numVars = varcList[loopIndex];
 	varListPtr = ckalloc(sizeof(ForeachVarList)
-		+ numVars * sizeof(int));
+		+ (numVars - 1) * sizeof(int));
 	varListPtr->numVars = numVars;
 	for (j = 0;  j < numVars;  j++) {
 	    const char *varName = varvList[loopIndex][j];
@@ -2642,131 +2638,77 @@ CompileEachloopCmd(
 	}
 	infoPtr->varLists[loopIndex] = varListPtr;
     }
-    infoIndex = TclCreateAuxData(infoPtr, &tclForeachInfoType, envPtr);
+    infoIndex = TclCreateAuxData(infoPtr, &tclNewForeachInfoType, envPtr);
 
     /*
-     * Create an exception record to handle [break] and [continue].
+     * Create the collecting object, unshared.
      */
-
-    range = TclCreateExceptRange(LOOP_EXCEPTION_RANGE, envPtr);
-
+    
+    if (collect == TCL_EACH_COLLECT) {
+	TclEmitInstInt4(INST_LIST, 0, envPtr);
+    }
+	    
     /*
-     * Evaluate then store each value list in the associated temporary.
+     * Evaluate each value list and leave it on stack.
      */
 
-    loopIndex = 0;
     for (i = 0, tokenPtr = parsePtr->tokenPtr;
 	    i < numWords-1;
 	    i++, tokenPtr = TokenAfter(tokenPtr)) {
 	if ((i%2 == 0) && (i > 0)) {
 	    CompileWord(envPtr, tokenPtr, interp, i);
-	    tempVar = (firstValueTemp + loopIndex);
-	    Emit14Inst(		INST_STORE_SCALAR, tempVar,	envPtr);
-	    TclEmitOpcode(	INST_POP,			envPtr);
-	    loopIndex++;
 	}
     }
 
-    /*
-     * Create temporary variable to capture return values from loop body.
-     */
-     
-    if (collect == TCL_EACH_COLLECT) {
-	PushStringLiteral(envPtr, "");
-	Emit14Inst(		INST_STORE_SCALAR, collectVar,	envPtr);
-	TclEmitOpcode(		INST_POP,			envPtr);
-    }
-
-    /*
-     * Initialize the temporary var that holds the count of loop iterations.
-     */
-
-    TclEmitInstInt4(		INST_FOREACH_START4, infoIndex,	envPtr);
-
-    /*
-     * Top of loop code: assign each loop variable and check whether
-     * to terminate the loop.
-     */
-
-    ExceptionRangeTarget(envPtr, range, continueOffset);
-    TclEmitInstInt4(		INST_FOREACH_STEP4, infoIndex,	envPtr);
-    TclEmitForwardJump(envPtr, TCL_FALSE_JUMP, &jumpFalseFixup);
-
+    TclEmitInstInt4(INST_FOREACH_START, infoIndex, envPtr);
+    
     /*
      * Inline compile the loop body.
      */
 
+    range = TclCreateExceptRange(LOOP_EXCEPTION_RANGE, envPtr);
+
     ExceptionRangeStarts(envPtr, range);
     BODY(bodyTokenPtr, numWords - 1);
     ExceptionRangeEnds(envPtr, range);
-
+    
     if (collect == TCL_EACH_COLLECT) {
-	Emit14Inst(		INST_LAPPEND_SCALAR, collectVar,envPtr);
-    }
-    TclEmitOpcode(		INST_POP,			envPtr);
-
-    /*
-     * Jump back to the test at the top of the loop. Generate a 4 byte jump if
-     * the distance to the test is > 120 bytes. This is conservative and
-     * ensures that we won't have to replace this jump if we later need to
-     * replace the ifFalse jump with a 4 byte jump.
-     */
-
-    jumpBackOffset = CurrentOffset(envPtr);
-    jumpBackDist = jumpBackOffset-envPtr->exceptArrayPtr[range].continueOffset;
-    if (jumpBackDist > 120) {
-	TclEmitInstInt4(INST_JUMP4, -jumpBackDist, envPtr);
+	TclEmitOpcode(INST_LMAP_COLLECT, envPtr);
     } else {
-	TclEmitInstInt1(INST_JUMP1, -jumpBackDist, envPtr);
+	TclEmitOpcode(		INST_POP,			envPtr);
     }
 
     /*
-     * Fix the target of the jump after the foreach_step test.
+     * Bottom of loop code: assign each loop variable and check whether
+     * to terminate the loop. Set the loop's break target. 
      */
 
-    if (TclFixupForwardJumpToHere(envPtr, &jumpFalseFixup, 127)) {
-	/*
-	 * Update the loop body's starting PC offset since it moved down.
-	 */
-
-	envPtr->exceptArrayPtr[range].codeOffset += 3;
-
-	/*
-	 * Update the jump back to the test at the top of the loop since it
-	 * also moved down 3 bytes.
-	 */
-
-	jumpBackOffset += 3;
-	jumpPc = (envPtr->codeStart + jumpBackOffset);
-	jumpBackDist += 3;
-	if (jumpBackDist > 120) {
-	    TclUpdateInstInt4AtPc(INST_JUMP4, -jumpBackDist, jumpPc);
-	} else {
-	    TclUpdateInstInt1AtPc(INST_JUMP1, -jumpBackDist, jumpPc);
-	}
-    }
+    ExceptionRangeTarget(envPtr, range, continueOffset);
+    TclEmitOpcode(INST_FOREACH_STEP, envPtr);
+    ExceptionRangeTarget(envPtr, range, breakOffset);
+    TclFinalizeLoopExceptionRange(envPtr, range);
+    TclEmitOpcode(INST_FOREACH_END, envPtr);
+    TclAdjustStackDepth(-(numLists+2), envPtr);
 
     /*
-     * Set the loop's break target.
+     * Set the jumpback distance from INST_FOREACH_STEP to the start of the
+     * body's code. Misuse loopCtTemp for storing the jump size.
      */
-
-    ExceptionRangeTarget(envPtr, range, breakOffset);
-    TclFinalizeLoopExceptionRange(envPtr, range);
+    
+    jumpBackOffset = envPtr->exceptArrayPtr[range].continueOffset -
+	    envPtr->exceptArrayPtr[range].codeOffset;
+    infoPtr->loopCtTemp = -jumpBackOffset;
 
     /*
-     * The command's result is an empty string if not collecting, or the
-     * list of results from evaluating the loop body.
+     * The command's result is an empty string if not collecting. If
+     * collecting, it is automatically left on stack after FOREACH_END.
      */
 
-    if (collect == TCL_EACH_COLLECT) {
-	Emit14Inst(		INST_LOAD_SCALAR, collectVar,	envPtr);
-	TclEmitInstInt1(INST_UNSET_SCALAR, 0,			envPtr);
-	TclEmitInt4(		collectVar,			envPtr);
-    } else {
+    if (collect != TCL_EACH_COLLECT) {
 	PushStringLiteral(envPtr, "");
     }
-
-  done:
+    
+    done:
     for (loopIndex = 0;  loopIndex < numLists;  loopIndex++) {
 	if (varvList[loopIndex] != NULL) {
 	    ckfree(varvList[loopIndex]);
@@ -2920,6 +2862,36 @@ PrintForeachInfo(
 	Tcl_AppendToObj(appendObj, "]", -1);
     }
 }
+
+static void
+PrintNewForeachInfo(
+    ClientData clientData,
+    Tcl_Obj *appendObj,
+    ByteCode *codePtr,
+    unsigned int pcOffset)
+{
+    register ForeachInfo *infoPtr = clientData;
+    register ForeachVarList *varsPtr;
+    int i, j;
+
+    Tcl_AppendPrintfToObj(appendObj, "jumpOffset=%+d, vars=",
+	    infoPtr->loopCtTemp);
+    for (i=0 ; i<infoPtr->numLists ; i++) {
+	if (i) {
+	    Tcl_AppendToObj(appendObj, ",", -1);
+	}
+	Tcl_AppendToObj(appendObj, "[", -1);
+	varsPtr = infoPtr->varLists[i];
+	for (j=0 ; j<varsPtr->numVars ; j++) {
+	    if (j) {
+		Tcl_AppendToObj(appendObj, ",", -1);
+	    }
+	    Tcl_AppendPrintfToObj(appendObj, "%%v%u",
+		    (unsigned) varsPtr->varIndexes[j]);
+	}
+	Tcl_AppendToObj(appendObj, "]", -1);
+    }
+}
 
 /*
  *----------------------------------------------------------------------
@@ -3126,7 +3098,7 @@ TclCompileFormatCmd(
 	 * Do the concatenation, which produces the result.
 	 */
 
-	TclEmitInstInt1(INST_CONCAT1, i, envPtr);
+	TclEmitInstInt1(INST_STR_CONCAT1, i, envPtr);
     } else {
 	/*
 	 * EVIL HACK! Force there to be a string representation in the case
diff --git a/generic/tclCompCmdsGR.c b/generic/tclCompCmdsGR.c
index d00327d..b3e273f 100644
--- a/generic/tclCompCmdsGR.c
+++ b/generic/tclCompCmdsGR.c
@@ -28,6 +28,58 @@ static void		CompileReturnInternal(CompileEnv *envPtr,
 static int		IndexTailVarIfKnown(Tcl_Interp *interp,
 			    Tcl_Token *varTokenPtr, CompileEnv *envPtr);
 
+#define INDEX_END	(-2)
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * GetIndexFromToken --
+ *
+ *	Parse a token and get the encoded version of the index (as understood
+ *	by TEBC), assuming it is at all knowable at compile time. Only handles
+ *	indices that are integers or 'end' or 'end-integer'.
+ *
+ * Returns:
+ *	TCL_OK if parsing succeeded, and TCL_ERROR if it failed.
+ *
+ * Side effects:
+ *	Sets *index to the index value if successful.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static inline int
+GetIndexFromToken(
+    Tcl_Token *tokenPtr,
+    int *index)
+{
+    Tcl_Obj *tmpObj = Tcl_NewObj();
+    int result, idx;
+
+    if (!TclWordKnownAtCompileTime(tokenPtr, tmpObj)) {
+	Tcl_DecrRefCount(tmpObj);
+	return TCL_ERROR;
+    }
+
+    result = TclGetIntFromObj(NULL, tmpObj, &idx);
+    if (result == TCL_OK) {
+	if (idx < 0) {
+	    result = TCL_ERROR;
+	}
+    } else {
+	result = TclGetIntForIndexM(NULL, tmpObj, INDEX_END, &idx);
+	if (result == TCL_OK && idx > INDEX_END) {
+	    result = TCL_ERROR;
+	}
+    }
+    Tcl_DecrRefCount(tmpObj);
+
+    if (result == TCL_OK) {
+	*index = idx;
+    }
+
+    return result;
+}
 
 /*
  *----------------------------------------------------------------------
@@ -229,6 +281,7 @@ TclCompileIfCmd(
 		SetLineInformation(wordIdx);
 		Tcl_ResetResult(interp);
 		TclCompileExprWords(interp, testTokenPtr, 1, envPtr);
+		TclClearNumConversion(envPtr);
 		if (jumpFalseFixupArray.next >= jumpFalseFixupArray.end) {
 		    TclExpandJumpFixupArray(&jumpFalseFixupArray);
 		}
@@ -478,6 +531,7 @@ TclCompileIncrCmd(
 	} else {
 	    SetLineInformation(2);
 	    CompileTokens(envPtr, incrTokenPtr, interp);
+	    TclClearNumConversion(envPtr);
 	}
     } else {			/* No incr amount given so use 1. */
 	haveImmValue = 1;
@@ -1027,7 +1081,7 @@ TclCompileLassignCmd(
      */
 
     TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx,	envPtr);
-    TclEmitInt4(		-2 /* == "end" */,		envPtr);
+    TclEmitInt4(			INDEX_END,		envPtr);
 
     return TCL_OK;
 }
@@ -1060,7 +1114,7 @@ TclCompileLindexCmd(
     CompileEnv *envPtr)		/* Holds resulting instructions. */
 {
     Tcl_Token *idxTokenPtr, *valTokenPtr;
-    int i, numWords = parsePtr->numWords;
+    int i, idx, numWords = parsePtr->numWords;
     DefineLineInformation;	/* TIP #280 */
 
     /*
@@ -1078,46 +1132,28 @@ TclCompileLindexCmd(
     }
 
     idxTokenPtr = TokenAfter(valTokenPtr);
-    if (idxTokenPtr->type == TCL_TOKEN_SIMPLE_WORD) {
-	Tcl_Obj *tmpObj;
-	int idx, result;
-
-	tmpObj = Tcl_NewStringObj(idxTokenPtr[1].start, idxTokenPtr[1].size);
-	result = TclGetIntFromObj(NULL, tmpObj, &idx);
-	if (result == TCL_OK) {
-	    if (idx < 0) {
-		result = TCL_ERROR;
-	    }
-	} else {
-	    result = TclGetIntForIndexM(NULL, tmpObj, -2, &idx);
-	    if (result == TCL_OK && idx > -2) {
-		result = TCL_ERROR;
-	    }
-	}
-	TclDecrRefCount(tmpObj);
-
-	if (result == TCL_OK) {
-	    /*
-	     * All checks have been completed, and we have exactly one of
-	     * these constructs:
-	     *	 lindex <arbitraryValue> <posInt>
-	     *	 lindex <arbitraryValue> end-<posInt>
-	     * This is best compiled as a push of the arbitrary value followed
-	     * by an "immediate lindex" which is the most efficient variety.
-	     */
-
-	    CompileWord(envPtr, valTokenPtr, interp, 1);
-	    TclEmitInstInt4(	INST_LIST_INDEX_IMM, idx,	envPtr);
-	    return TCL_OK;
-	}
-
+    if (GetIndexFromToken(idxTokenPtr, &idx) == TCL_OK) {
 	/*
-	 * If the conversion failed or the value was negative, we just keep on
-	 * going with the more complex compilation.
+	 * All checks have been completed, and we have exactly one of these
+	 * constructs:
+	 *	 lindex <arbitraryValue> <posInt>
+	 *	 lindex <arbitraryValue> end-<posInt>
+	 * This is best compiled as a push of the arbitrary value followed by
+	 * an "immediate lindex" which is the most efficient variety.
 	 */
+
+	CompileWord(envPtr, valTokenPtr, interp, 1);
+	TclEmitInstInt4(	INST_LIST_INDEX_IMM, idx,	envPtr);
+	return TCL_OK;
     }
 
     /*
+     * If the value was not known at compile time, the conversion failed or
+     * the value was negative, we just keep on going with the more complex
+     * compilation.
+     */
+
+    /*
      * Push the operands onto the stack.
      */
 
@@ -1263,7 +1299,7 @@ TclCompileListCmd(
 
     if (concat && numWords == 2) {
 	TclEmitInstInt4(	INST_LIST_RANGE_IMM, 0,	envPtr);
-	TclEmitInt4(			-2,		envPtr);
+	TclEmitInt4(			INDEX_END,	envPtr);
     }
     return TCL_OK;
 }
@@ -1330,8 +1366,7 @@ TclCompileLrangeCmd(
 {
     Tcl_Token *tokenPtr, *listTokenPtr;
     DefineLineInformation;	/* TIP #280 */
-    Tcl_Obj *tmpObj;
-    int idx1, idx2, result;
+    int idx1, idx2;
 
     if (parsePtr->numWords != 4) {
 	return TCL_ERROR;
@@ -1339,56 +1374,18 @@ TclCompileLrangeCmd(
     listTokenPtr = TokenAfter(parsePtr->tokenPtr);
 
     /*
-     * Parse the first index. Will only compile if it is constant and not an
+     * Parse the indices. Will only compile if both are constants and not an
      * _integer_ less than zero (since we reserve negative indices here for
-     * end-relative indexing).
+     * end-relative indexing) or an end-based index greater than 'end' itself.
      */
 
     tokenPtr = TokenAfter(listTokenPtr);
-    if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
-	return TCL_ERROR;
-    }
-    tmpObj = Tcl_NewStringObj(tokenPtr[1].start, tokenPtr[1].size);
-    result = TclGetIntFromObj(NULL, tmpObj, &idx1);
-    if (result == TCL_OK) {
-	if (idx1 < 0) {
-	    result = TCL_ERROR;
-	}
-    } else {
-	result = TclGetIntForIndexM(NULL, tmpObj, -2, &idx1);
-	if (result == TCL_OK && idx1 > -2) {
-	    result = TCL_ERROR;
-	}
-    }
-    TclDecrRefCount(tmpObj);
-    if (result != TCL_OK) {
+    if (GetIndexFromToken(tokenPtr, &idx1) != TCL_OK) {
 	return TCL_ERROR;
     }
 
-    /*
-     * Parse the second index. Will only compile if it is constant and not an
-     * _integer_ less than zero (since we reserve negative indices here for
-     * end-relative indexing).
-     */
-
     tokenPtr = TokenAfter(tokenPtr);
-    if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
-	return TCL_ERROR;
-    }
-    tmpObj = Tcl_NewStringObj(tokenPtr[1].start, tokenPtr[1].size);
-    result = TclGetIntFromObj(NULL, tmpObj, &idx2);
-    if (result == TCL_OK) {
-	if (idx2 < 0) {
-	    result = TCL_ERROR;
-	}
-    } else {
-	result = TclGetIntForIndexM(NULL, tmpObj, -2, &idx2);
-	if (result == TCL_OK && idx2 > -2) {
-	    result = TCL_ERROR;
-	}
-    }
-    TclDecrRefCount(tmpObj);
-    if (result != TCL_OK) {
+    if (GetIndexFromToken(tokenPtr, &idx2) != TCL_OK) {
 	return TCL_ERROR;
     }
 
@@ -1407,19 +1404,16 @@ TclCompileLrangeCmd(
 /*
  *----------------------------------------------------------------------
  *
- * TclCompileLreplaceCmd --
+ * TclCompileLinsertCmd --
  *
- *	How to compile the "lreplace" command. We only bother with the case
- *	where there are no elements to insert and where both the 'first' and
- *	'last' arguments are constant and one can be deterined to be at the
- *	end of the list. (This is the case that could also be written with
- *	"lrange".)
+ *	How to compile the "linsert" command. We only bother with the case
+ *	where the index is constant.
  *
  *----------------------------------------------------------------------
  */
 
 int
-TclCompileLreplaceCmd(
+TclCompileLinsertCmd(
     Tcl_Interp *interp,		/* Tcl interpreter for context. */
     Tcl_Parse *parsePtr,	/* Points to a parse structure for the
 				 * command. */
@@ -1429,101 +1423,272 @@ TclCompileLreplaceCmd(
 {
     Tcl_Token *tokenPtr, *listTokenPtr;
     DefineLineInformation;	/* TIP #280 */
-    Tcl_Obj *tmpObj;
-    int idx1, idx2, result, guaranteedDropAll = 0;
+    int idx, i;
 
-    if (parsePtr->numWords != 4) {
+    if (parsePtr->numWords < 3) {
 	return TCL_ERROR;
     }
     listTokenPtr = TokenAfter(parsePtr->tokenPtr);
 
     /*
-     * Parse the first index. Will only compile if it is constant and not an
+     * Parse the index. Will only compile if it is constant and not an
      * _integer_ less than zero (since we reserve negative indices here for
-     * end-relative indexing).
+     * end-relative indexing) or an end-based index greater than 'end' itself.
      */
 
     tokenPtr = TokenAfter(listTokenPtr);
-    if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
+    if (GetIndexFromToken(tokenPtr, &idx) != TCL_OK) {
 	return TCL_ERROR;
     }
-    tmpObj = Tcl_NewStringObj(tokenPtr[1].start, tokenPtr[1].size);
-    result = TclGetIntFromObj(NULL, tmpObj, &idx1);
-    if (result == TCL_OK) {
-	if (idx1 < 0) {
-	    result = TCL_ERROR;
-	}
+
+    /*
+     * There are four main cases. If there are no values to insert, this is
+     * just a confirm-listiness check. If the index is '0', this is a prepend.
+     * If the index is 'end' (== INDEX_END), this is an append. Otherwise,
+     * this is a splice (== split, insert values as list, concat-3).
+     */
+
+    CompileWord(envPtr, listTokenPtr, interp, 1);
+    if (parsePtr->numWords == 3) {
+	TclEmitInstInt4(	INST_LIST_RANGE_IMM, 0,		envPtr);
+	TclEmitInt4(			INDEX_END,		envPtr);
+	return TCL_OK;
+    }
+
+    for (i=3 ; i<parsePtr->numWords ; i++) {
+	tokenPtr = TokenAfter(tokenPtr);
+	CompileWord(envPtr, tokenPtr, interp, i);
+    }
+    TclEmitInstInt4(		INST_LIST, i-3,			envPtr);
+
+    if (idx == 0 /*start*/) {
+	TclEmitInstInt4(	INST_REVERSE, 2,		envPtr);
+	TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    } else if (idx == INDEX_END /*end*/) {
+	TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
     } else {
-	result = TclGetIntForIndexM(NULL, tmpObj, -2, &idx1);
-	if (result == TCL_OK && idx1 > -2) {
-	    result = TCL_ERROR;
+	if (idx < 0) {
+	    idx++;
 	}
+	TclEmitInstInt4(	INST_OVER, 1,			envPtr);
+	TclEmitInstInt4(	INST_LIST_RANGE_IMM, 0,		envPtr);
+	TclEmitInt4(			idx-1,			envPtr);
+	TclEmitInstInt4(	INST_REVERSE, 3,		envPtr);
+	TclEmitInstInt4(	INST_LIST_RANGE_IMM, idx,	envPtr);
+	TclEmitInt4(			INDEX_END,		envPtr);
+	TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+	TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
     }
-    TclDecrRefCount(tmpObj);
-    if (result != TCL_OK) {
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLreplaceCmd --
+ *
+ *	How to compile the "lreplace" command. We only bother with the case
+ *	where the indices are constant.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLreplaceCmd(
+    Tcl_Interp *interp,		/* Tcl interpreter for context. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the
+				 * command. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds the resulting instructions. */
+{
+    Tcl_Token *tokenPtr, *listTokenPtr;
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Obj *tmpObj;
+    int idx1, idx2, i, offset;
+
+    if (parsePtr->numWords < 4) {
 	return TCL_ERROR;
     }
+    listTokenPtr = TokenAfter(parsePtr->tokenPtr);
 
     /*
-     * Parse the second index. Will only compile if it is constant and not an
+     * Parse the indices. Will only compile if both are constants and not an
      * _integer_ less than zero (since we reserve negative indices here for
-     * end-relative indexing).
+     * end-relative indexing) or an end-based index greater than 'end' itself.
      */
 
-    tokenPtr = TokenAfter(tokenPtr);
-    if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
+    tokenPtr = TokenAfter(listTokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx1) != TCL_OK) {
 	return TCL_ERROR;
     }
-    tmpObj = Tcl_NewStringObj(tokenPtr[1].start, tokenPtr[1].size);
-    result = TclGetIntFromObj(NULL, tmpObj, &idx2);
-    if (result == TCL_OK) {
-	if (idx2 < 0) {
-	    result = TCL_ERROR;
-	}
-    } else {
-	result = TclGetIntForIndexM(NULL, tmpObj, -2, &idx2);
-	if (result == TCL_OK && idx2 > -2) {
-	    result = TCL_ERROR;
-	}
-    }
-    TclDecrRefCount(tmpObj);
-    if (result != TCL_OK) {
+
+    tokenPtr = TokenAfter(tokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx2) != TCL_OK) {
 	return TCL_ERROR;
     }
 
     /*
-     * Sanity check: can only issue when we're removing a range at one or
-     * other end of the list. If we're at one end or the other, convert the
-     * indices into the equivalent for an [lrange].
+     * Work out what this [lreplace] is actually doing.
      */
 
+    tmpObj = NULL;
+    CompileWord(envPtr, listTokenPtr, interp, 1);
+    if (parsePtr->numWords == 4) {
+	if (idx1 == 0) {
+	    if (idx2 == INDEX_END) {
+		goto dropAll;
+	    }
+	    idx1 = idx2 + 1;
+	    idx2 = INDEX_END;
+	    goto dropEnd;
+	} else if (idx2 == INDEX_END) {
+	    idx2 = idx1 - 1;
+	    idx1 = 0;
+	    goto dropEnd;
+	} else {
+	    if (idx1 > 0) {
+		tmpObj = Tcl_NewIntObj(idx1);
+		Tcl_IncrRefCount(tmpObj);
+	    }
+	    goto dropRange;
+	}
+    }
+
+    tokenPtr = TokenAfter(tokenPtr);
+    for (i=4 ; i<parsePtr->numWords ; i++) {
+	CompileWord(envPtr, tokenPtr, interp, i);
+	tokenPtr = TokenAfter(tokenPtr);
+    }
+    TclEmitInstInt4(		INST_LIST, i - 4,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
     if (idx1 == 0) {
-	if (idx2 == -2) {
-	    guaranteedDropAll = 1;
+	if (idx2 == INDEX_END) {
+	    goto replaceAll;
 	}
 	idx1 = idx2 + 1;
-	idx2 = -2;
-    } else if (idx2 == -2) {
+	idx2 = INDEX_END;
+	goto replaceHead;
+    } else if (idx2 == INDEX_END) {
 	idx2 = idx1 - 1;
 	idx1 = 0;
+	goto replaceTail;
     } else {
-	return TCL_ERROR;
+	if (idx1 > 0 && idx2 > 0 && idx2 < idx1) {
+	    idx2 = idx1 - 1;
+	} else if (idx1 < 0 && idx2 < 0 && idx2 < idx1) {
+	    idx2 = idx1 - 1;
+	}
+	if (idx1 > 0) {
+	    tmpObj = Tcl_NewIntObj(idx1);
+	    Tcl_IncrRefCount(tmpObj);
+	}
+	goto replaceRange;
     }
 
     /*
-     * Issue instructions. It's not safe to skip doing the LIST_RANGE, as
-     * we've not proved that the 'list' argument is really a list. Not that it
-     * is worth trying to do that given current knowledge.
+     * Issue instructions to perform the operations relating to configurations
+     * that just drop. The only argument pushed on the stack is the list to
+     * operate on.
      */
 
-    CompileWord(envPtr, listTokenPtr, interp, 1);
-    if (guaranteedDropAll) {
+  dropAll:
+    TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
+    TclEmitOpcode(		INST_POP,			envPtr);
+    PushStringLiteral(envPtr,	"");
+    goto done;
+
+  dropEnd:
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx1,	envPtr);
+    TclEmitInt4(			idx2,			envPtr);
+    goto done;
+
+  dropRange:
+    if (tmpObj != NULL) {
+	TclEmitOpcode(		INST_DUP,			envPtr);
 	TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
-	TclEmitOpcode(		INST_POP,			envPtr);
-	PushStringLiteral(envPtr, "");
-    } else {
-	TclEmitInstInt4(	INST_LIST_RANGE_IMM, idx1,	envPtr);
-	TclEmitInt4(		idx2,				envPtr);
+	TclEmitPush(TclAddLiteralObj(envPtr, tmpObj, NULL),	envPtr);
+	TclEmitOpcode(		INST_GT,			envPtr);
+	offset = CurrentOffset(envPtr);
+	TclEmitInstInt1(	INST_JUMP_TRUE1, 0,		envPtr);
+	TclEmitPush(TclAddLiteralObj(envPtr, Tcl_ObjPrintf(
+		"list doesn't contain element %d", idx1), NULL), envPtr);
+	CompileReturnInternal(envPtr, INST_RETURN_IMM, TCL_ERROR, 0,
+		Tcl_ObjPrintf("-errorcode {TCL OPERATION LREPLACE BADIDX}"));
+	TclStoreInt1AtPtr(CurrentOffset(envPtr) - offset,
+		envPtr->codeStart + offset + 1);
+	TclAdjustStackDepth(-1, envPtr);
+    }
+    TclEmitOpcode(		INST_DUP,			envPtr);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, 0,		envPtr);
+    TclEmitInt4(			idx1 - 1,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx2 + 1,	envPtr);
+    TclEmitInt4(			INDEX_END,		envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    goto done;
+
+    /*
+     * Issue instructions to perform the operations relating to configurations
+     * that do real replacement. All arguments are pushed and assembled into a
+     * pair: the list of values to replace with, and the list to do the
+     * surgery on.
+     */
+
+  replaceAll:
+    TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
+    TclEmitOpcode(		INST_POP,			envPtr);
+    goto done;
+
+  replaceHead:
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx1,	envPtr);
+    TclEmitInt4(			idx2,			envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    goto done;
+
+  replaceTail:
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx1,	envPtr);
+    TclEmitInt4(			idx2,			envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    goto done;
+
+  replaceRange:
+    if (tmpObj != NULL) {
+	TclEmitOpcode(		INST_DUP,			envPtr);
+	TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
+	TclEmitPush(TclAddLiteralObj(envPtr, tmpObj, NULL),	envPtr);
+	TclEmitOpcode(		INST_GT,			envPtr);
+	offset = CurrentOffset(envPtr);
+	TclEmitInstInt1(	INST_JUMP_TRUE1, 0,		envPtr);
+	TclEmitPush(TclAddLiteralObj(envPtr, Tcl_ObjPrintf(
+		"list doesn't contain element %d", idx1), NULL), envPtr);
+	CompileReturnInternal(envPtr, INST_RETURN_IMM, TCL_ERROR, 0,
+		Tcl_ObjPrintf("-errorcode {TCL OPERATION LREPLACE BADIDX}"));
+	TclStoreInt1AtPtr(CurrentOffset(envPtr) - offset,
+		envPtr->codeStart + offset + 1);
+	TclAdjustStackDepth(-1, envPtr);
+    }
+    TclEmitOpcode(		INST_DUP,			envPtr);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, 0,		envPtr);
+    TclEmitInt4(			idx1 - 1,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx2 + 1,	envPtr);
+    TclEmitInt4(			INDEX_END,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 3,		envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    goto done;
+
+    /*
+     * Clean up the allocated memory.
+     */
+
+  done:
+    if (tmpObj != NULL) {
+	Tcl_DecrRefCount(tmpObj);
     }
     return TCL_OK;
 }
@@ -1791,6 +1956,28 @@ TclCompileNamespaceCodeCmd(
 }
 
 int
+TclCompileNamespaceOriginCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr;
+    DefineLineInformation;	/* TIP #280 */
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    CompileWord(envPtr,	tokenPtr,			interp, 1);
+    TclEmitOpcode(	INST_ORIGIN_COMMAND,		envPtr);
+    return TCL_OK;
+}
+
+int
 TclCompileNamespaceQualifiersCmd(
     Tcl_Interp *interp,		/* Used for error reporting. */
     Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
@@ -2852,6 +3039,66 @@ IndexTailVarIfKnown(
     return localIndex;
 }
 
+/*
+ * ----------------------------------------------------------------------
+ *
+ * TclCompileObjectNextCmd, TclCompileObjectSelfCmd --
+ *
+ *	Compilations of the TclOO utility commands [next] and [self].
+ *
+ * ----------------------------------------------------------------------
+ */
+
+int
+TclCompileObjectNextCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr = parsePtr->tokenPtr;
+    int i;
+
+    if (parsePtr->numWords > 255) {
+	return TCL_ERROR;
+    }
+
+    for (i=0 ; i<parsePtr->numWords ; i++) {
+	CompileWord(envPtr, tokenPtr, interp, i);
+	tokenPtr = TokenAfter(tokenPtr);
+    }
+    TclEmitInstInt1(	INST_TCLOO_NEXT, i,		envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileObjectNextToCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr = parsePtr->tokenPtr;
+    int i;
+
+    if (parsePtr->numWords < 2 || parsePtr->numWords > 255) {
+	return TCL_ERROR;
+    }
+
+    for (i=0 ; i<parsePtr->numWords ; i++) {
+	CompileWord(envPtr, tokenPtr, interp, i);
+	tokenPtr = TokenAfter(tokenPtr);
+    }
+    TclEmitInstInt1(	INST_TCLOO_NEXT_CLASS, i,	envPtr);
+    return TCL_OK;
+}
+
 int
 TclCompileObjectSelfCmd(
     Tcl_Interp *interp,		/* Used for error reporting. */
diff --git a/generic/tclCompCmdsSZ.c b/generic/tclCompCmdsSZ.c
index 754238f..e6ec0a6 100644
--- a/generic/tclCompCmdsSZ.c
+++ b/generic/tclCompCmdsSZ.c
@@ -17,6 +17,7 @@
 
 #include "tclInt.h"
 #include "tclCompile.h"
+#include "tclStringTrim.h"
 
 /*
  * Prototypes for procedures defined later in this file:
@@ -101,6 +102,59 @@ const AuxDataType tclJumptableInfoType = {
     if ((idx)<256) {OP1(STORE_SCALAR1,(idx));} else {OP4(STORE_SCALAR4,(idx));}
 #define INVOKE(name) \
     TclEmitInvoke(envPtr,INST_##name)
+
+#define INDEX_END	(-2)
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * GetIndexFromToken --
+ *
+ *	Parse a token and get the encoded version of the index (as understood
+ *	by TEBC), assuming it is at all knowable at compile time. Only handles
+ *	indices that are integers or 'end' or 'end-integer'.
+ *
+ * Returns:
+ *	TCL_OK if parsing succeeded, and TCL_ERROR if it failed.
+ *
+ * Side effects:
+ *	Sets *index to the index value if successful.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static inline int
+GetIndexFromToken(
+    Tcl_Token *tokenPtr,
+    int *index)
+{
+    Tcl_Obj *tmpObj = Tcl_NewObj();
+    int result, idx;
+
+    if (!TclWordKnownAtCompileTime(tokenPtr, tmpObj)) {
+	Tcl_DecrRefCount(tmpObj);
+	return TCL_ERROR;
+    }
+
+    result = TclGetIntFromObj(NULL, tmpObj, &idx);
+    if (result == TCL_OK) {
+	if (idx < 0) {
+	    result = TCL_ERROR;
+	}
+    } else {
+	result = TclGetIntForIndexM(NULL, tmpObj, INDEX_END, &idx);
+	if (result == TCL_OK && idx > INDEX_END) {
+	    result = TCL_ERROR;
+	}
+    }
+    Tcl_DecrRefCount(tmpObj);
+
+    if (result == TCL_OK) {
+	*index = idx;
+    }
+
+    return result;
+}
 
 /*
  *----------------------------------------------------------------------
@@ -371,6 +425,284 @@ TclCompileStringIndexCmd(
 }
 
 int
+TclCompileStringIsCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    static const char *const isClasses[] = {
+	"alnum",	"alpha",	"ascii",	"control",
+	"boolean",	"digit",	"double",	"entier",
+	"false",	"graph",	"integer",	"list",
+	"lower",	"print",	"punct",	"space",
+	"true",		"upper",	"wideinteger",	"wordchar",
+	"xdigit",	NULL
+    };
+    enum isClasses {
+	STR_IS_ALNUM,	STR_IS_ALPHA,	STR_IS_ASCII,	STR_IS_CONTROL,
+	STR_IS_BOOL,	STR_IS_DIGIT,	STR_IS_DOUBLE,	STR_IS_ENTIER,
+	STR_IS_FALSE,	STR_IS_GRAPH,	STR_IS_INT,	STR_IS_LIST,
+	STR_IS_LOWER,	STR_IS_PRINT,	STR_IS_PUNCT,	STR_IS_SPACE,
+	STR_IS_TRUE,	STR_IS_UPPER,	STR_IS_WIDE,	STR_IS_WORD,
+	STR_IS_XDIGIT
+    };
+    int t, range, allowEmpty = 0, end;
+    InstStringClassType strClassType;
+    Tcl_Obj *isClass;
+
+    if (parsePtr->numWords < 3 || parsePtr->numWords > 6) {
+	return TCL_ERROR;
+    }
+    isClass = Tcl_NewObj();
+    if (!TclWordKnownAtCompileTime(tokenPtr, isClass)) {
+	Tcl_DecrRefCount(isClass);
+	return TCL_ERROR;
+    } else if (Tcl_GetIndexFromObj(interp, isClass, isClasses, "class", 0,
+	    &t) != TCL_OK) {
+	Tcl_DecrRefCount(isClass);
+	TclCompileSyntaxError(interp, envPtr);
+	return TCL_OK;
+    }
+    Tcl_DecrRefCount(isClass);
+
+#define GotLiteral(tokenPtr, word) \
+    ((tokenPtr)->type == TCL_TOKEN_SIMPLE_WORD &&			\
+     (tokenPtr)[1].size > 1 &&						\
+     (tokenPtr)[1].start[0] == word[0] &&				\
+     strncmp((tokenPtr)[1].start, (word), (tokenPtr)[1].size) == 0)
+
+    /*
+     * Cannot handle the -failindex option at all, and that's the only legal
+     * way to have more than 4 arguments.
+     */
+
+    if (parsePtr->numWords != 3 && parsePtr->numWords != 4) {
+	return TCL_ERROR;
+    }
+
+    tokenPtr = TokenAfter(tokenPtr);
+    if (parsePtr->numWords == 3) {
+	allowEmpty = 1;
+    } else {
+	if (!GotLiteral(tokenPtr, "-strict")) {
+	    return TCL_ERROR;
+	}
+	tokenPtr = TokenAfter(tokenPtr);
+    }
+#undef GotLiteral
+
+    /*
+     * Compile the code. There are several main classes of check here.
+     *	1. Character classes
+     *	2. Booleans
+     *	3. Integers
+     *	4. Floats
+     *	5. Lists
+     */
+
+    CompileWord(envPtr, tokenPtr, interp, parsePtr->numWords-1);
+
+    switch ((enum isClasses) t) {
+    case STR_IS_ALNUM:
+	strClassType = STR_CLASS_ALNUM;
+	goto compileStrClass;
+    case STR_IS_ALPHA:
+	strClassType = STR_CLASS_ALPHA;
+	goto compileStrClass;
+    case STR_IS_ASCII:
+	strClassType = STR_CLASS_ASCII;
+	goto compileStrClass;
+    case STR_IS_CONTROL:
+	strClassType = STR_CLASS_CONTROL;
+	goto compileStrClass;
+    case STR_IS_DIGIT:
+	strClassType = STR_CLASS_DIGIT;
+	goto compileStrClass;
+    case STR_IS_GRAPH:
+	strClassType = STR_CLASS_GRAPH;
+	goto compileStrClass;
+    case STR_IS_LOWER:
+	strClassType = STR_CLASS_LOWER;
+	goto compileStrClass;
+    case STR_IS_PRINT:
+	strClassType = STR_CLASS_PRINT;
+	goto compileStrClass;
+    case STR_IS_PUNCT:
+	strClassType = STR_CLASS_PUNCT;
+	goto compileStrClass;
+    case STR_IS_SPACE:
+	strClassType = STR_CLASS_SPACE;
+	goto compileStrClass;
+    case STR_IS_UPPER:
+	strClassType = STR_CLASS_UPPER;
+	goto compileStrClass;
+    case STR_IS_WORD:
+	strClassType = STR_CLASS_WORD;
+	goto compileStrClass;
+    case STR_IS_XDIGIT:
+	strClassType = STR_CLASS_XDIGIT;
+    compileStrClass:
+	if (allowEmpty) {
+	    OP1(	STR_CLASS, strClassType);
+	} else {
+	    int over, over2;
+
+	    OP(		DUP);
+	    OP1(	STR_CLASS, strClassType);
+	    JUMP1(	JUMP_TRUE, over);
+	    OP(		POP);
+	    PUSH(	"0");
+	    JUMP1(	JUMP, over2);
+	    FIXJUMP1(over);
+	    PUSH(	"");
+	    OP(		STR_NEQ);
+	    FIXJUMP1(over2);
+	}
+	return TCL_OK;
+
+    case STR_IS_BOOL:
+    case STR_IS_FALSE:
+    case STR_IS_TRUE:
+	OP(		TRY_CVT_TO_BOOLEAN);
+	switch (t) {
+	    int over, over2;
+
+	case STR_IS_BOOL:
+	    if (allowEmpty) {
+		JUMP1(	JUMP_TRUE, over);
+		PUSH(	"");
+		OP(	STR_EQ);
+		JUMP1(	JUMP, over2);
+		FIXJUMP1(over);
+		OP(	POP);
+		PUSH(	"1");
+		FIXJUMP1(over2);
+	    } else {
+		OP4(	REVERSE, 2);
+		OP(	POP);
+	    }
+	    return TCL_OK;
+	case STR_IS_TRUE:
+	    JUMP1(	JUMP_TRUE, over);
+	    if (allowEmpty) {
+		PUSH(	"");
+		OP(	STR_EQ);
+	    } else {
+		OP(	POP);
+		PUSH(	"0");
+	    }
+	    FIXJUMP1(	over);
+	    OP(		LNOT);
+	    OP(		LNOT);
+	    return TCL_OK;
+	case STR_IS_FALSE:
+	    JUMP1(	JUMP_TRUE, over);
+	    if (allowEmpty) {
+		PUSH(	"");
+		OP(	STR_NEQ);
+	    } else {
+		OP(	POP);
+		PUSH(	"1");
+	    }
+	    FIXJUMP1(	over);
+	    OP(		LNOT);
+	    return TCL_OK;
+	}
+
+    case STR_IS_DOUBLE: {
+	int satisfied, isEmpty;
+
+	if (allowEmpty) {
+	    OP(		DUP);
+	    PUSH(	"");
+	    OP(		STR_EQ);
+	    JUMP1(	JUMP_TRUE, isEmpty);
+	    OP(		NUM_TYPE);
+	    JUMP1(	JUMP_TRUE, satisfied);
+	    PUSH(	"0");
+	    JUMP1(	JUMP, end);
+	    FIXJUMP1(	isEmpty);
+	    OP(		POP);
+	    FIXJUMP1(	satisfied);
+	} else {
+	    OP(		NUM_TYPE);
+	    JUMP1(	JUMP_TRUE, satisfied);
+	    PUSH(	"0");
+	    JUMP1(	JUMP, end);
+	    TclAdjustStackDepth(-1, envPtr);
+	    FIXJUMP1(	satisfied);
+	}
+	PUSH(		"1");
+	FIXJUMP1(	end);
+	return TCL_OK;
+    }
+
+    case STR_IS_INT:
+    case STR_IS_WIDE:
+    case STR_IS_ENTIER:
+	if (allowEmpty) {
+	    int testNumType;
+
+	    OP(		DUP);
+	    OP(		NUM_TYPE);
+	    OP(		DUP);
+	    JUMP1(	JUMP_TRUE, testNumType);
+	    OP(		POP);
+	    PUSH(	"");
+	    OP(		STR_EQ);
+	    JUMP1(	JUMP, end);
+	    TclAdjustStackDepth(1, envPtr);
+	    FIXJUMP1(	testNumType);
+	    OP4(	REVERSE, 2);
+	    OP(		POP);
+	} else {
+	    OP(		NUM_TYPE);
+	    OP(		DUP);
+	    JUMP1(	JUMP_FALSE, end);
+	}
+
+	switch (t) {
+	case STR_IS_INT:
+	    PUSH(	"1");
+	    OP(		EQ);
+	    break;
+	case STR_IS_WIDE:
+	    PUSH(	"2");
+	    OP(		LE);
+	    break;
+	case STR_IS_ENTIER:
+	    PUSH(	"3");
+	    OP(		LE);
+	    break;
+	}
+	FIXJUMP1(	end);
+	return TCL_OK;
+
+    case STR_IS_LIST:
+	range = TclCreateExceptRange(CATCH_EXCEPTION_RANGE, envPtr);
+	OP4(		BEGIN_CATCH4, range);
+	ExceptionRangeStarts(envPtr, range);
+	OP(		DUP);
+	OP(		LIST_LENGTH);
+	OP(		POP);
+	ExceptionRangeEnds(envPtr, range);
+	ExceptionRangeTarget(envPtr, range, catchOffset);
+	OP(		POP);
+	OP(		PUSH_RETURN_CODE);
+	OP(		END_CATCH);
+	OP(		LNOT);
+	return TCL_OK;
+    }
+
+    return TclCompileBasicMin0ArgCmd(interp, parsePtr, cmdPtr, envPtr);
+}
+
+int
 TclCompileStringMatchCmd(
     Tcl_Interp *interp,		/* Used for error reporting. */
     Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
@@ -565,8 +897,7 @@ TclCompileStringRangeCmd(
 {
     DefineLineInformation;	/* TIP #280 */
     Tcl_Token *stringTokenPtr, *fromTokenPtr, *toTokenPtr;
-    Tcl_Obj *tmpObj;
-    int idx1, idx2, result;
+    int idx1, idx2;
 
     if (parsePtr->numWords != 4) {
 	return TCL_ERROR;
@@ -576,50 +907,13 @@ TclCompileStringRangeCmd(
     toTokenPtr = TokenAfter(fromTokenPtr);
 
     /*
-     * Parse the first index. Will only compile if it is constant and not an
-     * _integer_ less than zero (since we reserve negative indices here for
-     * end-relative indexing).
+     * Parse the two indices.
      */
 
-    tmpObj = Tcl_NewObj();
-    result = TCL_ERROR;
-    if (TclWordKnownAtCompileTime(fromTokenPtr, tmpObj)) {
-	if (TclGetIntFromObj(NULL, tmpObj, &idx1) == TCL_OK) {
-	    if (idx1 >= 0) {
-		result = TCL_OK;
-	    }
-	} else if (TclGetIntForIndexM(NULL, tmpObj, -2, &idx1) == TCL_OK) {
-	    if (idx1 <= -2) {
-		result = TCL_OK;
-	    }
-	}
-    }
-    TclDecrRefCount(tmpObj);
-    if (result != TCL_OK) {
+    if (GetIndexFromToken(fromTokenPtr, &idx1) != TCL_OK) {
 	goto nonConstantIndices;
     }
-
-    /*
-     * Parse the second index. Will only compile if it is constant and not an
-     * _integer_ less than zero (since we reserve negative indices here for
-     * end-relative indexing).
-     */
-
-    tmpObj = Tcl_NewObj();
-    result = TCL_ERROR;
-    if (TclWordKnownAtCompileTime(toTokenPtr, tmpObj)) {
-	if (TclGetIntFromObj(NULL, tmpObj, &idx2) == TCL_OK) {
-	    if (idx2 >= 0) {
-		result = TCL_OK;
-	    }
-	} else if (TclGetIntForIndexM(NULL, tmpObj, -2, &idx2) == TCL_OK) {
-	    if (idx2 <= -2) {
-		result = TCL_OK;
-	    }
-	}
-    }
-    TclDecrRefCount(tmpObj);
-    if (result != TCL_OK) {
+    if (GetIndexFromToken(toTokenPtr, &idx2) != TCL_OK) {
 	goto nonConstantIndices;
     }
 
@@ -642,6 +936,320 @@ TclCompileStringRangeCmd(
     OP(			STR_RANGE);
     return TCL_OK;
 }
+
+int
+TclCompileStringReplaceCmd(
+    Tcl_Interp *interp,		/* Tcl interpreter for context. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the
+				 * command. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds the resulting instructions. */
+{
+    Tcl_Token *tokenPtr, *valueTokenPtr, *replacementTokenPtr = NULL;
+    DefineLineInformation;	/* TIP #280 */
+    int idx1, idx2;
+
+    if (parsePtr->numWords < 4 || parsePtr->numWords > 5) {
+	return TCL_ERROR;
+    }
+    valueTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    if (parsePtr->numWords == 5) {
+	tokenPtr = TokenAfter(valueTokenPtr);
+	tokenPtr = TokenAfter(tokenPtr);
+	replacementTokenPtr = TokenAfter(tokenPtr);
+    }
+
+    /*
+     * Parse the indices. Will only compile special cases if both are
+     * constants and not an _integer_ less than zero (since we reserve
+     * negative indices here for end-relative indexing) or an end-based index
+     * greater than 'end' itself.
+     */
+
+    tokenPtr = TokenAfter(valueTokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx1) != TCL_OK) {
+	goto genericReplace;
+    }
+
+    tokenPtr = TokenAfter(tokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx2) != TCL_OK) {
+	goto genericReplace;
+    }
+
+    /*
+     * We handle these replacements specially: first character (where
+     * idx1=idx2=0) and last character (where idx1=idx2=INDEX_END). Anything
+     * else and the semantics get rather screwy.
+     */
+
+    if (idx1 == 0 && idx2 == 0) {
+	int notEq, end;
+
+	/*
+	 * Just working with the first character.
+	 */
+
+	CompileWord(envPtr, valueTokenPtr, interp, 1);
+	if (replacementTokenPtr == NULL) {
+	    /* Drop first */
+	    OP44(	STR_RANGE_IMM, 1, INDEX_END);
+	    return TCL_OK;
+	}
+	/* Replace first */
+	CompileWord(envPtr, replacementTokenPtr, interp, 4);
+	OP4(		OVER, 1);
+	PUSH(		"");
+	OP(		STR_EQ);
+	JUMP1(		JUMP_FALSE, notEq);
+	OP(		POP);
+	JUMP1(		JUMP, end);
+	FIXJUMP1(notEq);
+	TclAdjustStackDepth(1, envPtr);
+	OP4(		REVERSE, 2);
+	OP44(		STR_RANGE_IMM, 1, INDEX_END);
+	OP1(		STR_CONCAT1, 2);
+	FIXJUMP1(end);
+	return TCL_OK;
+
+    } else if (idx1 == INDEX_END && idx2 == INDEX_END) {
+	int notEq, end;
+
+	/*
+	 * Just working with the last character.
+	 */
+
+	CompileWord(envPtr, valueTokenPtr, interp, 1);
+	if (replacementTokenPtr == NULL) {
+	    /* Drop last */
+	    OP44(	STR_RANGE_IMM, 0, INDEX_END-1);
+	    return TCL_OK;
+	}
+	/* Replace last */
+	CompileWord(envPtr, replacementTokenPtr, interp, 4);
+	OP4(		OVER, 1);
+	PUSH(		"");
+	OP(		STR_EQ);
+	JUMP1(		JUMP_FALSE, notEq);
+	OP(		POP);
+	JUMP1(		JUMP, end);
+	FIXJUMP1(notEq);
+	TclAdjustStackDepth(1, envPtr);
+	OP4(		REVERSE, 2);
+	OP44(		STR_RANGE_IMM, 0, INDEX_END-1);
+	OP4(		REVERSE, 2);
+	OP1(		STR_CONCAT1, 2);
+	FIXJUMP1(end);
+	return TCL_OK;
+
+    } else {
+	/*
+	 * Need to process indices at runtime. This could be because the
+	 * indices are not constants, or because we need to resolve them to
+	 * absolute indices to work out if a replacement is going to happen.
+	 * In any case, to runtime it is.
+	 */
+
+    genericReplace:
+	CompileWord(envPtr, valueTokenPtr, interp, 1);
+	tokenPtr = TokenAfter(valueTokenPtr);
+	CompileWord(envPtr, tokenPtr, interp, 2);
+	tokenPtr = TokenAfter(tokenPtr);
+	CompileWord(envPtr, tokenPtr, interp, 3);
+	if (replacementTokenPtr != NULL) {
+	    CompileWord(envPtr, replacementTokenPtr, interp, 4);
+	} else {
+	    PUSH(	"");
+	}
+	OP(		STR_REPLACE);
+	return TCL_OK;
+    }
+}
+
+int
+TclCompileStringTrimLCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr;
+
+    if (parsePtr->numWords != 2 && parsePtr->numWords != 3) {
+	return TCL_ERROR;
+    }
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    CompileWord(envPtr, tokenPtr,			interp, 1);
+    if (parsePtr->numWords == 3) {
+	tokenPtr = TokenAfter(tokenPtr);
+	CompileWord(envPtr, tokenPtr,			interp, 2);
+    } else {
+	PushLiteral(envPtr, tclDefaultTrimSet, strlen(tclDefaultTrimSet));
+    }
+    OP(			STR_TRIM_LEFT);
+    return TCL_OK;
+}
+
+int
+TclCompileStringTrimRCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr;
+
+    if (parsePtr->numWords != 2 && parsePtr->numWords != 3) {
+	return TCL_ERROR;
+    }
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    CompileWord(envPtr, tokenPtr,			interp, 1);
+    if (parsePtr->numWords == 3) {
+	tokenPtr = TokenAfter(tokenPtr);
+	CompileWord(envPtr, tokenPtr,			interp, 2);
+    } else {
+	PushLiteral(envPtr, tclDefaultTrimSet, strlen(tclDefaultTrimSet));
+    }
+    OP(			STR_TRIM_RIGHT);
+    return TCL_OK;
+}
+
+int
+TclCompileStringTrimCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr;
+
+    if (parsePtr->numWords != 2 && parsePtr->numWords != 3) {
+	return TCL_ERROR;
+    }
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    CompileWord(envPtr, tokenPtr,			interp, 1);
+    if (parsePtr->numWords == 3) {
+	tokenPtr = TokenAfter(tokenPtr);
+	CompileWord(envPtr, tokenPtr,			interp, 2);
+    } else {
+	PushLiteral(envPtr, tclDefaultTrimSet, strlen(tclDefaultTrimSet));
+    }
+    OP(			STR_TRIM);
+    return TCL_OK;
+}
+
+int
+TclCompileStringToUpperCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr;
+
+    if (parsePtr->numWords != 2) {
+	return TclCompileBasic1To3ArgCmd(interp, parsePtr, cmdPtr, envPtr);
+    }
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    CompileWord(envPtr, tokenPtr,			interp, 1);
+    OP(			STR_UPPER);
+    return TCL_OK;
+}
+
+int
+TclCompileStringToLowerCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr;
+
+    if (parsePtr->numWords != 2) {
+	return TclCompileBasic1To3ArgCmd(interp, parsePtr, cmdPtr, envPtr);
+    }
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    CompileWord(envPtr, tokenPtr,			interp, 1);
+    OP(			STR_LOWER);
+    return TCL_OK;
+}
+
+int
+TclCompileStringToTitleCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr;
+
+    if (parsePtr->numWords != 2) {
+	return TclCompileBasic1To3ArgCmd(interp, parsePtr, cmdPtr, envPtr);
+    }
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    CompileWord(envPtr, tokenPtr,			interp, 1);
+    OP(			STR_TITLE);
+    return TCL_OK;
+}
+
+/*
+ * Support definitions for the [string is] compilation.
+ */
+
+static int
+UniCharIsAscii(
+    int character)
+{
+    return (character >= 0) && (character < 0x80);
+}
+
+static int
+UniCharIsHexDigit(
+    int character)
+{
+    return (character >= 0) && (character < 0x80) && isxdigit(character);
+}
+
+StringClassDesc const tclStringClassTable[] = {
+    {"alnum",	Tcl_UniCharIsAlnum},
+    {"alpha",	Tcl_UniCharIsAlpha},
+    {"ascii",	UniCharIsAscii},
+    {"control", Tcl_UniCharIsControl},
+    {"digit",	Tcl_UniCharIsDigit},
+    {"graph",	Tcl_UniCharIsGraph},
+    {"lower",	Tcl_UniCharIsLower},
+    {"print",	Tcl_UniCharIsPrint},
+    {"punct",	Tcl_UniCharIsPunct},
+    {"space",	Tcl_UniCharIsSpace},
+    {"upper",	Tcl_UniCharIsUpper},
+    {"word",	Tcl_UniCharIsWordChar},
+    {"xdigit",	UniCharIsHexDigit},
+    {NULL,	NULL}
+};
 
 /*
  *----------------------------------------------------------------------
@@ -752,7 +1360,7 @@ TclSubstCompile(
     /*
      * Tricky point! If the first token does not result in a *guaranteed* push
      * of a Tcl_Obj on the stack, we must push an empty object. Otherwise it
-     * is possible to get to an INST_CONCAT1 or INST_DONE without enough
+     * is possible to get to an INST_STR_CONCAT1 or INST_DONE without enough
      * values on the stack, resulting in a crash. Thanks to Joe Mistachkin for
      * identifying a script that could trigger this case.
      */
@@ -817,11 +1425,11 @@ TclSubstCompile(
 	}
 
 	while (count > 255) {
-	    OP1(		CONCAT1, 255);
+	    OP1(		STR_CONCAT1, 255);
 	    count -= 254;
 	}
 	if (count > 1) {
-	    OP1(		CONCAT1, count);
+	    OP1(		STR_CONCAT1, count);
 	    count = 1;
 	}
 
@@ -941,7 +1549,7 @@ TclSubstCompile(
 		    (int) (CurrentOffset(envPtr) - okFixup.codeOffset));
 	}
 	if (count > 1) {
-	    OP1(CONCAT1, count);
+	    OP1(STR_CONCAT1, count);
 	    count = 1;
 	}
 
@@ -954,11 +1562,11 @@ TclSubstCompile(
     }
 
     while (count > 255) {
-	OP1(	CONCAT1, 255);
+	OP1(	STR_CONCAT1, 255);
 	count -= 254;
     }
     if (count > 1) {
-	OP1(	CONCAT1, count);
+	OP1(	STR_CONCAT1, count);
     }
 
     Tcl_FreeParse(&parse);
@@ -3071,6 +3679,7 @@ TclCompileWhileCmd(
 	}
 	SetLineInformation(1);
 	TclCompileExprWords(interp, testTokenPtr, 1, envPtr);
+	TclClearNumConversion(envPtr);
 
 	jumpDist = CurrentOffset(envPtr) - bodyCodeOffset;
 	if (jumpDist > 127) {
@@ -3151,6 +3760,51 @@ TclCompileYieldCmd(
 /*
  *----------------------------------------------------------------------
  *
+ * TclCompileYieldToCmd --
+ *
+ *	Procedure called to compile the "yieldto" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "yieldto" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileYieldToCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    int i;
+
+    if (parsePtr->numWords < 2) {
+	return TCL_ERROR;
+    }
+
+    OP(		NS_CURRENT);
+    for (i = 1 ; i < parsePtr->numWords ; i++) {
+	CompileWord(envPtr, tokenPtr, interp, i);
+	tokenPtr = TokenAfter(tokenPtr);
+    }
+    OP4(	LIST, i);
+    OP(		YIELD_TO_INVOKE);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * CompileUnaryOpCmd --
  *
  *	Utility routine to compile the unary operator commands.
diff --git a/generic/tclCompile.c b/generic/tclCompile.c
index 3c8e4ef..347e3f0 100644
--- a/generic/tclCompile.c
+++ b/generic/tclCompile.c
@@ -63,7 +63,7 @@ InstructionDesc const tclInstructionTable[] = {
 	/* Pop the topmost stack object */
     {"dup",		  1,   +1,         0,	{OPERAND_NONE}},
 	/* Duplicate the topmost stack object and push the result */
-    {"concat1",		  2,   INT_MIN,    1,	{OPERAND_UINT1}},
+    {"strcat",		  2,   INT_MIN,    1,	{OPERAND_UINT1}},
 	/* Concatenate the top op1 items and push result */
     {"invokeStk1",	  2,   INT_MIN,    1,	{OPERAND_UINT1}},
 	/* Invoke command named objv[0]; <objc,objv> = <op1,top op1> */
@@ -493,6 +493,7 @@ InstructionDesc const tclInstructionTable[] = {
 	 * qualified version, or produces the empty string if no such command
 	 * exists. Never generates errors.
 	 * Stack:  ... cmdName => ... fullCmdName */
+
     {"tclooSelf",	 1,	+1,	  0,	{OPERAND_NONE}},
 	/* Push the identity of the current TclOO object (i.e., the name of
 	 * its current public access command) on the stack. */
@@ -545,6 +546,110 @@ InstructionDesc const tclInstructionTable[] = {
 	/* Drops an element from the auxiliary stack, popping stack elements
 	 * until the matching stack depth is reached. */
 
+    /* New foreach implementation */
+    {"foreach_start",	 5,	+2,	  1,	{OPERAND_AUX4}},
+	/* Initialize execution of a foreach loop. Operand is aux data index
+	 * of the ForeachInfo structure for the foreach command. It pushes 2
+	 * elements which hold runtime params for foreach_step, they are later
+	 * dropped by foreach_end together with the value lists. NOTE that the
+	 * iterator-tracker and info reference must not be passed to bytecodes
+	 * that handle normal Tcl values. NOTE that this instruction jumps to
+	 * the foreach_step instruction paired with it; the stack info below
+	 * is only nominal.
+	 * Stack: ... listObjs... => ... listObjs... iterTracker info */
+    {"foreach_step",	 1,	 0,	  0,	{OPERAND_NONE}},
+	/* "Step" or begin next iteration of foreach loop. Assigns to foreach
+	 * iteration variables. May jump to straight after the foreach_start
+	 * that pushed the iterTracker and info values. MUST be followed
+	 * immediately by a foreach_end.
+	 * Stack: ... listObjs... iterTracker info =>
+	 *				... listObjs... iterTracker info */
+    {"foreach_end",	 1,	 0,	  0,	{OPERAND_NONE}},
+	/* Clean up a foreach loop by dropping the info value, the tracker
+	 * value and the lists that were being iterated over.
+	 * Stack: ... listObjs... iterTracker info => ... */
+    {"lmap_collect",	 1,	-1,	  0,	{OPERAND_NONE}},
+	/* Appends the value at the top of the stack to the list located on
+	 * the stack the "other side" of the foreach-related values.
+	 * Stack: ... collector listObjs... iterTracker info value =>
+	 *			... collector listObjs... iterTracker info */
+
+    {"strtrim",		 1,	-1,	  0,	{OPERAND_NONE}},
+	/* [string trim] core: removes the characters (designated by the value
+	 * at the top of the stack) from both ends of the string and pushes
+	 * the resulting string.
+	 * Stack: ... string charset => ... trimmedString */
+    {"strtrimLeft",	 1,	-1,	  0,	{OPERAND_NONE}},
+	/* [string trimleft] core: removes the characters (designated by the
+	 * value at the top of the stack) from the left of the string and
+	 * pushes the resulting string.
+	 * Stack: ... string charset => ... trimmedString */
+    {"strtrimRight",	 1,	-1,	  0,	{OPERAND_NONE}},
+	/* [string trimright] core: removes the characters (designated by the
+	 * value at the top of the stack) from the right of the string and
+	 * pushes the resulting string.
+	 * Stack: ... string charset => ... trimmedString */
+
+    {"concatStk",	 5,	INT_MIN,  1,	{OPERAND_UINT4}},
+	/* Wrapper round Tcl_ConcatObj(), used for [concat] and [eval]. opnd
+	 * is number of values to concatenate.
+	 * Operation:	push concat(stk1 stk2 ... stktop) */
+
+    {"strcaseUpper",	 1,	0,	  0,	{OPERAND_NONE}},
+	/* [string toupper] core: converts whole string to upper case using
+	 * the default (extended "C" locale) rules.
+	 * Stack: ... string => ... newString */
+    {"strcaseLower",	 1,	0,	  0,	{OPERAND_NONE}},
+	/* [string tolower] core: converts whole string to upper case using
+	 * the default (extended "C" locale) rules.
+	 * Stack: ... string => ... newString */
+    {"strcaseTitle",	 1,	0,	  0,	{OPERAND_NONE}},
+	/* [string totitle] core: converts whole string to upper case using
+	 * the default (extended "C" locale) rules.
+	 * Stack: ... string => ... newString */
+    {"strreplace",	 1,	-3,	  0,	{OPERAND_NONE}},
+	/* [string replace] core: replaces a non-empty range of one string
+	 * with the contents of another.
+	 * Stack: ... string fromIdx toIdx replacement => ... newString */
+
+    {"originCmd",	 1,	0,	  0,	{OPERAND_NONE}},
+	/* Reports which command was the origin (via namespace import chain)
+	 * of the command named on the top of the stack.
+	 * Stack:  ... cmdName => ... fullOriginalCmdName */
+
+    {"tclooNext",	 2,	INT_MIN,  1,	{OPERAND_UINT1}},
+	/* Call the next item on the TclOO call chain, passing opnd arguments
+	 * (min 1, max 255, *includes* "next").  The result of the invoked
+	 * method implementation will be pushed on the stack in place of the
+	 * arguments (similar to invokeStk).
+	 * Stack:  ... "next" arg2 arg3 -- argN => ... result */
+    {"tclooNextClass",	 2,	INT_MIN,  1,	{OPERAND_UINT1}},
+	/* Call the following item on the TclOO call chain defined by class
+	 * className, passing opnd arguments (min 2, max 255, *includes*
+	 * "nextto" and the class name). The result of the invoked method
+	 * implementation will be pushed on the stack in place of the
+	 * arguments (similar to invokeStk).
+	 * Stack:  ... "nextto" className arg3 arg4 -- argN => ... result */
+
+    {"yieldToInvoke",	 1,	0,	  0,	{OPERAND_NONE}},
+	/* Makes the current coroutine yield the value at the top of the
+	 * stack, invoking the given command/args with resolution in the given
+	 * namespace (all packed into a list), and places the list of values
+	 * that are the response back on top of the stack when it resumes.
+	 * Stack:  ... [list ns cmd arg1 ... argN] => ... resumeList */
+
+    {"numericType",	 1,	0,	  0,	{OPERAND_NONE}},
+	/* Pushes the numeric type code of the word at the top of the stack.
+	 * Stack:  ... value => ... typeCode */
+    {"tryCvtToBoolean",	 1,	+1,	  0,	{OPERAND_NONE}},
+	/* Try converting stktop to boolean if possible. No errors.
+	 * Stack:  ... value => ... value isStrictBool */
+    {"strclass",	 2,	0,	  1,	{OPERAND_SCLS1}},
+	/* See if all the characters of the given string are a member of the
+	 * specified (by opnd) character class. Note that an empty string will
+	 * satisfy the class check (standard definition of "all").
+	 * Stack:  ... stringValue => ... boolean */
+
     {NULL, 0, 0, 0, {OPERAND_NONE}}
 };
 
@@ -754,7 +859,9 @@ TclSetByteCodeFromAny(
      * instruction generator boundaries.
      */
 
-    TclOptimizeBytecode(&compEnv);
+    if (iPtr->extra.optimizer) {
+	(iPtr->extra.optimizer)(&compEnv);
+    }
 
     /*
      * Invoke the compilation hook procedure if one exists.
@@ -1709,7 +1816,7 @@ TclCompileInvocation(
     int numWords,
     CompileEnv *envPtr)
 {
-    int wordIdx = 0;
+    int wordIdx = 0, depth = TclGetStackDepth(envPtr);
     DefineLineInformation;
 
     if (cmdObj) {
@@ -1742,6 +1849,7 @@ TclCompileInvocation(
     } else {
 	TclEmitInvoke(envPtr, INST_INVOKE_STK4, wordIdx);
     }
+    TclCheckStackDepth(depth+1, envPtr);
 }
 
 static void
@@ -1754,7 +1862,8 @@ CompileExpanded(
 {
     int wordIdx = 0;
     DefineLineInformation;
-
+    int depth = TclGetStackDepth(envPtr);
+    
     StartExpanding(envPtr);
     if (cmdObj) {
 	CompileCmdLiteral(interp, cmdObj, envPtr);
@@ -1800,6 +1909,7 @@ CompileExpanded(
      */
 
     TclEmitInvoke(envPtr, INST_INVOKE_EXPANDED, wordIdx);
+    TclCheckStackDepth(depth+1, envPtr);
 }
 
 static int 
@@ -1811,6 +1921,7 @@ CompileCmdCompileProc(
 {
     int unwind = 0, incrOffset = -1;
     DefineLineInformation;
+    int depth = TclGetStackDepth(envPtr);
 
     /*
      * Emit of the INST_START_CMD instruction is controlled by the value of
@@ -1858,6 +1969,7 @@ CompileCmdCompileProc(
 		TclStoreInt4AtPtr(envPtr->codeNext - startPtr, startPtr + 1);
 	    }
 	}
+	TclCheckStackDepth(depth+1, envPtr);
 	return TCL_OK;
     }
 
@@ -1900,7 +2012,8 @@ CompileCommandTokens(
     int *clNext = envPtr->clNext;
     int cmdIdx = envPtr->numCommands;
     int startCodeOffset = envPtr->codeNext - envPtr->codeStart;
-
+    int depth = TclGetStackDepth(envPtr);
+    
     assert (parsePtr->numWords > 0);
 
     /* Pre-Compile */
@@ -1991,6 +2104,7 @@ CompileCommandTokens(
     eclPtr->loc[wlineat].line = wlines;
     eclPtr->loc[wlineat].next = NULL;
 
+    TclCheckStackDepth(depth, envPtr);
     return cmdIdx;
 }
 
@@ -2010,6 +2124,7 @@ TclCompileScript(
 				 * Initial value of -1 indicates this routine
 				 * has not yet generated any bytecode. */
     const char *p = script;	/* Where we are in our compile. */
+    int depth = TclGetStackDepth(envPtr);
 
     if (envPtr->iPtr == NULL) {
 	Tcl_Panic("TclCompileScript() called on uninitialized CompileEnv");
@@ -2121,6 +2236,7 @@ TclCompileScript(
 	envPtr->codeNext--;
 	envPtr->currStackDepth++;
     }
+    TclCheckStackDepth(depth+1, envPtr);
 }
 
 /*
@@ -2231,6 +2347,7 @@ TclCompileTokens(
 #define NUM_STATIC_POS 20
     int isLiteral, maxNumCL, numCL;
     int *clPosition = NULL;
+    int depth = TclGetStackDepth(envPtr);
 
     /*
      * For the handling of continuation lines in literals we first check if
@@ -2384,11 +2501,11 @@ TclCompileTokens(
      */
 
     while (numObjsToConcat > 255) {
-	TclEmitInstInt1(INST_CONCAT1, 255, envPtr);
+	TclEmitInstInt1(INST_STR_CONCAT1, 255, envPtr);
 	numObjsToConcat -= 254;	/* concat pushes 1 obj, the result */
     }
     if (numObjsToConcat > 1) {
-	TclEmitInstInt1(INST_CONCAT1, numObjsToConcat, envPtr);
+	TclEmitInstInt1(INST_STR_CONCAT1, numObjsToConcat, envPtr);
     }
 
     /*
@@ -2408,6 +2525,7 @@ TclCompileTokens(
     if (maxNumCL) {
 	ckfree(clPosition);
     }
+    TclCheckStackDepth(depth+1, envPtr);
 }
 
 /*
@@ -2519,11 +2637,11 @@ TclCompileExprWords(
     }
     concatItems = 2*numWords - 1;
     while (concatItems > 255) {
-	TclEmitInstInt1(INST_CONCAT1, 255, envPtr);
+	TclEmitInstInt1(INST_STR_CONCAT1, 255, envPtr);
 	concatItems -= 254;
     }
     if (concatItems > 1) {
-	TclEmitInstInt1(INST_CONCAT1, concatItems, envPtr);
+	TclEmitInstInt1(INST_STR_CONCAT1, concatItems, envPtr);
     }
     TclEmitOpcode(INST_EXPR_STK, envPtr);
 }
@@ -3923,7 +4041,8 @@ TclEmitInvoke(
     ExceptionAux *auxBreakPtr, *auxContinuePtr;
     int arg1, arg2, wordCount = 0, expandCount = 0;
     int loopRange = 0, breakRange = 0, continueRange = 0;
-
+    int cleanup, depth = TclGetStackDepth(envPtr);
+    
     /*
      * Parse the arguments.
      */
@@ -3931,30 +4050,31 @@ TclEmitInvoke(
     va_start(argList, opcode);
     switch (opcode) {
     case INST_INVOKE_STK1:
-	wordCount = arg1 = va_arg(argList, int);
+	wordCount = arg1 = cleanup = va_arg(argList, int);
 	arg2 = 0;
 	break;
     case INST_INVOKE_STK4:
-	wordCount = arg1 = va_arg(argList, int);
+	wordCount = arg1 = cleanup = va_arg(argList, int);
 	arg2 = 0;
 	break;
     case INST_INVOKE_REPLACE:
 	arg1 = va_arg(argList, int);
 	arg2 = va_arg(argList, int);
 	wordCount = arg1 + arg2 - 1;
+	cleanup = arg1 + 1;
 	break;
     default:
 	Tcl_Panic("unexpected opcode");
     case INST_EVAL_STK:
-	wordCount = 1;
+	wordCount = cleanup = 1;
 	arg1 = arg2 = 0;
 	break;
     case INST_RETURN_STK:
-	wordCount = 2;
+	wordCount = cleanup = 2;
 	arg1 = arg2 = 0;
 	break;
     case INST_INVOKE_EXPANDED:
-	wordCount = arg1 = va_arg(argList, int);
+	wordCount = arg1 = cleanup = va_arg(argList, int);
 	arg2 = 0;
 	expandCount = 1;
 	break;
@@ -4057,6 +4177,7 @@ TclEmitInvoke(
 	    ExceptionRangeTarget(envPtr, loopRange, breakOffset);
 	    TclCleanupStackForBreakContinue(envPtr, auxBreakPtr);
 	    TclAddLoopBreakFixup(envPtr, auxBreakPtr);
+	    TclAdjustStackDepth(1, envPtr);
 
 	    envPtr->currStackDepth = savedStackDepth;
 	    envPtr->expandCount = savedExpandCount;
@@ -4068,6 +4189,7 @@ TclEmitInvoke(
 	    ExceptionRangeTarget(envPtr, loopRange, continueOffset);
 	    TclCleanupStackForBreakContinue(envPtr, auxContinuePtr);
 	    TclAddLoopContinueFixup(envPtr, auxContinuePtr);
+	    TclAdjustStackDepth(1, envPtr);
 
 	    envPtr->currStackDepth = savedStackDepth;
 	    envPtr->expandCount = savedExpandCount;
@@ -4076,6 +4198,7 @@ TclEmitInvoke(
 	TclFinalizeLoopExceptionRange(envPtr, loopRange);
 	TclFixupForwardJumpToHere(envPtr, &nonTrapFixup, 127);
     }
+    TclCheckStackDepth(depth+1-cleanup, envPtr);
 }
 
 /*
@@ -4974,6 +5097,11 @@ FormatInstruction(
 	    }
 	    Tcl_AppendPrintfToObj(bufferObj, "%%v%u ", (unsigned) opnd);
 	    break;
+	case OPERAND_SCLS1:
+	    opnd = TclGetUInt1AtPtr(pc+numBytes); numBytes++;
+	    Tcl_AppendPrintfToObj(bufferObj, "%s ",
+		    tclStringClassTable[opnd].name);
+	    break;
 	case OPERAND_NONE:
 	default:
 	    break;
@@ -5190,7 +5318,7 @@ PrintSourceToObj(
     int maxChars)		/* Maximum number of chars to print. */
 {
     register const char *p;
-    register int i = 0;
+    register int i = 0, len;
 
     if (stringPtr == NULL) {
 	Tcl_AppendToObj(appendObj, "\"\"", -1);
@@ -5199,32 +5327,50 @@ PrintSourceToObj(
 
     Tcl_AppendToObj(appendObj, "\"", -1);
     p = stringPtr;
-    for (;  (*p != '\0') && (i < maxChars);  p++, i++) {
-	switch (*p) {
+    for (;  (*p != '\0') && (i < maxChars);  p+=len) {
+	Tcl_UniChar ch;
+
+	len = TclUtfToUniChar(p, &ch);
+	switch (ch) {
 	case '"':
 	    Tcl_AppendToObj(appendObj, "\\\"", -1);
+	    i += 2;
 	    continue;
 	case '\f':
 	    Tcl_AppendToObj(appendObj, "\\f", -1);
+	    i += 2;
 	    continue;
 	case '\n':
 	    Tcl_AppendToObj(appendObj, "\\n", -1);
+	    i += 2;
 	    continue;
 	case '\r':
 	    Tcl_AppendToObj(appendObj, "\\r", -1);
+	    i += 2;
 	    continue;
 	case '\t':
 	    Tcl_AppendToObj(appendObj, "\\t", -1);
+	    i += 2;
 	    continue;
 	case '\v':
 	    Tcl_AppendToObj(appendObj, "\\v", -1);
+	    i += 2;
 	    continue;
 	default:
-	    Tcl_AppendPrintfToObj(appendObj, "%c", *p);
+	    if (ch < 0x20 || ch >= 0x7f) {
+		Tcl_AppendPrintfToObj(appendObj, "\\u%04x", ch);
+		i += 6;
+	    } else {
+		Tcl_AppendPrintfToObj(appendObj, "%c", ch);
+		i++;
+	    }
 	    continue;
 	}
     }
     Tcl_AppendToObj(appendObj, "\"", -1);
+    if (*p != '\0') {
+	Tcl_AppendToObj(appendObj, "...", -1);
+    }
 }
 
 #ifdef TCL_COMPILE_STATS
diff --git a/generic/tclCompile.h b/generic/tclCompile.h
index a39e0f1..5665ca9 100644
--- a/generic/tclCompile.h
+++ b/generic/tclCompile.h
@@ -512,7 +512,7 @@ typedef struct ByteCode {
 #define INST_PUSH4			2
 #define INST_POP			3
 #define INST_DUP			4
-#define INST_CONCAT1			5
+#define INST_STR_CONCAT1		5
 #define INST_INVOKE_STK1		6
 #define INST_INVOKE_STK4		7
 #define INST_EVAL_STK			8
@@ -586,8 +586,8 @@ typedef struct ByteCode {
 #define INST_CONTINUE			66
 
 /* Opcodes 67 to 68 */
-#define INST_FOREACH_START4		67
-#define INST_FOREACH_STEP4		68
+#define INST_FOREACH_START4		67 /* DEPRECATED */
+#define INST_FOREACH_STEP4		68 /* DEPRECATED */
 
 /* Opcodes 69 to 72 */
 #define INST_BEGIN_CATCH4		69
@@ -751,6 +751,8 @@ typedef struct ByteCode {
 #define INST_INFO_LEVEL_NUM		152
 #define INST_INFO_LEVEL_ARGS		153
 #define INST_RESOLVE_COMMAND		154
+
+/* For compilation relating to TclOO */
 #define INST_TCLOO_SELF			155
 #define INST_TCLOO_CLASS		156
 #define INST_TCLOO_NS			157
@@ -768,8 +770,37 @@ typedef struct ByteCode {
 
 #define INST_EXPAND_DROP		165
 
+/* New foreach implementation */
+#define INST_FOREACH_START              166
+#define INST_FOREACH_STEP               167
+#define INST_FOREACH_END                168
+#define INST_LMAP_COLLECT               169
+
+/* For compilation of [string trim] and related */
+#define INST_STR_TRIM			170
+#define INST_STR_TRIM_LEFT		171
+#define INST_STR_TRIM_RIGHT		172
+
+#define INST_CONCAT_STK			173
+
+#define INST_STR_UPPER			174
+#define INST_STR_LOWER			175
+#define INST_STR_TITLE			176
+#define INST_STR_REPLACE		177
+
+#define INST_ORIGIN_COMMAND		178
+
+#define INST_TCLOO_NEXT			179
+#define INST_TCLOO_NEXT_CLASS		180
+
+#define INST_YIELD_TO_INVOKE		181
+
+#define INST_NUM_TYPE			182
+#define INST_TRY_CVT_TO_BOOLEAN		183
+#define INST_STR_CLASS			184
+
 /* The last opcode */
-#define LAST_INST_OPCODE		165
+#define LAST_INST_OPCODE		184
 
 /*
  * Table describing the Tcl bytecode instructions: their name (for displaying
@@ -794,8 +825,9 @@ typedef enum InstOperandType {
 				 * variable table. */
     OPERAND_LVT4,		/* Four byte unsigned index into the local
 				 * variable table. */
-    OPERAND_AUX4		/* Four byte unsigned index into the aux data
+    OPERAND_AUX4,		/* Four byte unsigned index into the aux data
 				 * table. */
+    OPERAND_SCLS1		/* Index into tclStringClassTable. */
 } InstOperandType;
 
 typedef struct InstructionDesc {
@@ -814,6 +846,40 @@ typedef struct InstructionDesc {
 MODULE_SCOPE InstructionDesc const tclInstructionTable[];
 
 /*
+ * Constants used by INST_STRING_CLASS to indicate character classes. These
+ * correspond closely by name with what [string is] can support, but there is
+ * no requirement to keep the values the same.
+ */
+
+typedef enum InstStringClassType {
+    STR_CLASS_ALNUM,		/* Unicode alphabet or digit characters. */
+    STR_CLASS_ALPHA,		/* Unicode alphabet characters. */
+    STR_CLASS_ASCII,		/* Characters in range U+000000..U+00007F. */
+    STR_CLASS_CONTROL,		/* Unicode control characters. */
+    STR_CLASS_DIGIT,		/* Unicode digit characters. */
+    STR_CLASS_GRAPH,		/* Unicode printing characters, excluding
+				 * space. */
+    STR_CLASS_LOWER,		/* Unicode lower-case alphabet characters. */
+    STR_CLASS_PRINT,		/* Unicode printing characters, including
+				 * spaces. */
+    STR_CLASS_PUNCT,		/* Unicode punctuation characters. */
+    STR_CLASS_SPACE,		/* Unicode space characters. */
+    STR_CLASS_UPPER,		/* Unicode upper-case alphabet characters. */
+    STR_CLASS_WORD,		/* Unicode word (alphabetic, digit, connector
+				 * punctuation) characters. */
+    STR_CLASS_XDIGIT		/* Characters that can be used as digits in
+				 * hexadecimal numbers ([0-9A-Fa-f]). */
+} InstStringClassType;
+
+typedef struct StringClassDesc {
+    const char *name;		/* Name of the class. */
+    int (*comparator)(int);	/* Function to test if a single unicode
+				 * character is a member of the class. */
+} StringClassDesc;
+
+MODULE_SCOPE StringClassDesc const tclStringClassTable[];
+
+/*
  * Compilation of some Tcl constructs such as if commands and the logical or
  * (||) and logical and (&&) operators in expressions requires the generation
  * of forward jumps. Since the PC target of these jumps isn't known when the
@@ -902,6 +968,7 @@ typedef struct ForeachInfo {
 } ForeachInfo;
 
 MODULE_SCOPE const AuxDataType tclForeachInfoType;
+MODULE_SCOPE const AuxDataType tclNewForeachInfoType;
 
 #define FOREACHINFO(envPtr, index) \
     ((ForeachInfo*)((envPtr)->auxDataArrayPtr[TclGetUInt4AtPtr(index)].clientData))
@@ -1056,7 +1123,7 @@ MODULE_SCOPE void	TclFinalizeLoopExceptionRange(CompileEnv *envPtr,
 MODULE_SCOPE char *	TclLiteralStats(LiteralTable *tablePtr);
 MODULE_SCOPE int	TclLog2(int value);
 #endif
-MODULE_SCOPE void	TclOptimizeBytecode(CompileEnv *envPtr);
+MODULE_SCOPE void	TclOptimizeBytecode(void *envPtr);
 #ifdef TCL_COMPILE_DEBUG
 MODULE_SCOPE void	TclPrintByteCodeObj(Tcl_Interp *interp,
 			    Tcl_Obj *objPtr);
@@ -1071,8 +1138,6 @@ MODULE_SCOPE void	TclPushVarName(Tcl_Interp *interp,
 			    Tcl_Token *varTokenPtr, CompileEnv *envPtr,
 			    int flags, int *localIndexPtr,
 			    int *isScalarPtr);
-MODULE_SCOPE int	TclRegisterLiteral(CompileEnv *envPtr,
-			    char *bytes, int length, int flags);
 MODULE_SCOPE void	TclReleaseLiteral(Tcl_Interp *interp, Tcl_Obj *objPtr);
 MODULE_SCOPE void	TclInvalidateCmdLiteral(Tcl_Interp *interp, 
 			    const char *name, Namespace *nsPtr);
@@ -1163,6 +1228,21 @@ MODULE_SCOPE Tcl_Obj	*TclNewInstNameObj(unsigned char inst);
 	(envPtr)->currStackDepth += (delta);				\
     } while (0)
 
+#define TclGetStackDepth(envPtr)		\
+    ((envPtr)->currStackDepth)
+
+#define TclSetStackDepth(depth, envPtr)		\
+    (envPtr)->currStackDepth = (depth)
+
+#define TclCheckStackDepth(depth, envPtr)				\
+    do {								\
+	int dd = (depth);						\
+	if (dd != (envPtr)->currStackDepth) {				\
+	    Tcl_Panic("bad stack depth computations: is %i, should be %i", \
+		    (envPtr)->currStackDepth, dd);		\
+	}								\
+    } while (0)
+
 /*
  * Macro used to update the stack requirements. It is called by the macros
  * TclEmitOpCode, TclEmitInst1 and TclEmitInst4.
@@ -1303,6 +1383,18 @@ MODULE_SCOPE Tcl_Obj	*TclNewInstNameObj(unsigned char inst);
     } while (0)
 
 /*
+ * If the expr compiler finished with TRY_CONVERT, macro to remove it when the
+ * job is done by the following instruction.
+ */
+
+#define TclClearNumConversion(envPtr) \
+    do {								\
+	if (*(envPtr->codeNext - 1) == INST_TRY_CVT_TO_NUMERIC) {	\
+	    envPtr->codeNext--;						\
+	}								\
+    } while (0)
+
+/*
  * Macros to update a (signed or unsigned) integer starting at a pointer. The
  * two variants depend on the number of bytes. The ANSI C "prototypes" for
  * these macros are:
diff --git a/generic/tclDecls.h b/generic/tclDecls.h
index 830c998..91c0add 100644
--- a/generic/tclDecls.h
+++ b/generic/tclDecls.h
@@ -63,7 +63,7 @@ EXTERN void		Tcl_DbCkfree(char *ptr, const char *file, int line);
 /* 8 */
 EXTERN char *		Tcl_DbCkrealloc(char *ptr, unsigned int size,
 				const char *file, int line);
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 /* 9 */
 EXTERN void		Tcl_CreateFileHandler(int fd, int mask,
 				Tcl_FileProc *proc, ClientData clientData);
@@ -73,7 +73,7 @@ EXTERN void		Tcl_CreateFileHandler(int fd, int mask,
 EXTERN void		Tcl_CreateFileHandler(int fd, int mask,
 				Tcl_FileProc *proc, ClientData clientData);
 #endif /* MACOSX */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 /* 10 */
 EXTERN void		Tcl_DeleteFileHandler(int fd);
 #endif /* UNIX */
@@ -511,7 +511,7 @@ EXTERN Tcl_Interp *	Tcl_GetMaster(Tcl_Interp *interp);
 EXTERN const char *	Tcl_GetNameOfExecutable(void);
 /* 166 */
 EXTERN Tcl_Obj *	Tcl_GetObjResult(Tcl_Interp *interp);
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 /* 167 */
 EXTERN int		Tcl_GetOpenFile(Tcl_Interp *interp,
 				const char *chanID, int forWriting,
@@ -1835,19 +1835,19 @@ typedef struct TclStubs {
     char * (*tcl_DbCkalloc) (unsigned int size, const char *file, int line); /* 6 */
     void (*tcl_DbCkfree) (char *ptr, const char *file, int line); /* 7 */
     char * (*tcl_DbCkrealloc) (char *ptr, unsigned int size, const char *file, int line); /* 8 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     void (*tcl_CreateFileHandler) (int fd, int mask, Tcl_FileProc *proc, ClientData clientData); /* 9 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     void (*reserved9)(void);
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
     void (*tcl_CreateFileHandler) (int fd, int mask, Tcl_FileProc *proc, ClientData clientData); /* 9 */
 #endif /* MACOSX */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     void (*tcl_DeleteFileHandler) (int fd); /* 10 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     void (*reserved10)(void);
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
@@ -2009,10 +2009,10 @@ typedef struct TclStubs {
     Tcl_Interp * (*tcl_GetMaster) (Tcl_Interp *interp); /* 164 */
     const char * (*tcl_GetNameOfExecutable) (void); /* 165 */
     Tcl_Obj * (*tcl_GetObjResult) (Tcl_Interp *interp); /* 166 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     int (*tcl_GetOpenFile) (Tcl_Interp *interp, const char *chanID, int forWriting, int checkUsage, ClientData *filePtr); /* 167 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     void (*reserved167)(void);
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
@@ -2513,7 +2513,7 @@ extern const TclStubs *tclStubsPtr;
 	(tclStubsPtr->tcl_DbCkfree) /* 7 */
 #define Tcl_DbCkrealloc \
 	(tclStubsPtr->tcl_DbCkrealloc) /* 8 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 #define Tcl_CreateFileHandler \
 	(tclStubsPtr->tcl_CreateFileHandler) /* 9 */
 #endif /* UNIX */
@@ -2521,7 +2521,7 @@ extern const TclStubs *tclStubsPtr;
 #define Tcl_CreateFileHandler \
 	(tclStubsPtr->tcl_CreateFileHandler) /* 9 */
 #endif /* MACOSX */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 #define Tcl_DeleteFileHandler \
 	(tclStubsPtr->tcl_DeleteFileHandler) /* 10 */
 #endif /* UNIX */
@@ -2841,7 +2841,7 @@ extern const TclStubs *tclStubsPtr;
 	(tclStubsPtr->tcl_GetNameOfExecutable) /* 165 */
 #define Tcl_GetObjResult \
 	(tclStubsPtr->tcl_GetObjResult) /* 166 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 #define Tcl_GetOpenFile \
 	(tclStubsPtr->tcl_GetOpenFile) /* 167 */
 #endif /* UNIX */
diff --git a/generic/tclEncoding.c b/generic/tclEncoding.c
index 2cc55d6..d246cb2 100644
--- a/generic/tclEncoding.c
+++ b/generic/tclEncoding.c
@@ -182,6 +182,7 @@ TCL_DECLARE_MUTEX(encodingMutex)
 
 static Tcl_Encoding defaultEncoding;
 static Tcl_Encoding systemEncoding;
+Tcl_Encoding tclIdentityEncoding;
 
 /*
  * The following variable is used in the sparse matrix code for a
@@ -567,7 +568,7 @@ TclInitEncodingSubsystem(void)
     type.freeProc	= NULL;
     type.nullSize	= 1;
     type.clientData	= NULL;
-    Tcl_CreateEncoding(&type);
+    tclIdentityEncoding = Tcl_CreateEncoding(&type);
 
     type.encodingName	= "utf-8";
     type.toUtfProc	= UtfExtToUtfIntProc;
@@ -651,6 +652,7 @@ TclFinalizeEncodingSubsystem(void)
     Tcl_MutexLock(&encodingMutex);
     encodingsInitialized = 0;
     FreeEncoding(systemEncoding);
+    FreeEncoding(tclIdentityEncoding);
 
     hPtr = Tcl_FirstHashEntry(&encodingTable, &search);
     while (hPtr != NULL) {
diff --git a/generic/tclEnv.c b/generic/tclEnv.c
index 6a21947..cd1a954 100644
--- a/generic/tclEnv.c
+++ b/generic/tclEnv.c
@@ -444,7 +444,7 @@ TclUnsetEnv(
      * that no = should be included, and Windows requires it.
      */
 
-#if defined(__WIN32__) || defined(__CYGWIN__)
+#if defined(_WIN32) || defined(__CYGWIN__)
     string = ckalloc(length + 2);
     memcpy(string, name, (size_t) length);
     string[length] = '=';
@@ -453,7 +453,7 @@ TclUnsetEnv(
     string = ckalloc(length + 1);
     memcpy(string, name, (size_t) length);
     string[length] = '\0';
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
     Tcl_UtfToExternalDString(NULL, string, -1, &envString);
     string = ckrealloc(string, Tcl_DStringLength(&envString) + 1);
@@ -614,7 +614,8 @@ EnvTraceProc(
 	const char *value = TclGetEnv(name2, &valueString);
 
 	if (value == NULL) {
-	    return (char *) "no such variable";
+	    Tcl_UnsetVar2(interp, name1, name2, 0);
+	    return NULL;
 	}
 	Tcl_SetVar2(interp, name1, name2, value, 0);
 	Tcl_DStringFree(&valueString);
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index d3c1227..41730d3 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -174,29 +174,24 @@ static BuiltinFunc const tclBuiltinFuncTable[] = {
 typedef struct TEBCdata {
     ByteCode *codePtr;		/* Constant until the BC returns */
 				/* -----------------------------------------*/
-    const unsigned char *pc;	/* These fields are used on return TO this */
-    ptrdiff_t *catchTop;	/* this level: they record the state when a */
-    int cleanup;		/* new codePtr was received for NR */
-    Tcl_Obj *auxObjList;	/* execution. */
-    int checkInterp;
-    CmdFrame cmdFrame;
+    ptrdiff_t *catchTop;	/* These fields are used on return TO this */
+    Tcl_Obj *auxObjList;	/* this level: they record the state when a */
+    CmdFrame cmdFrame;		/* new codePtr was received for NR */
+                                /* execution. */
     void *stack[1];		/* Start of the actual combined catch and obj
 				 * stacks; the struct will be expanded as
 				 * necessary */
 } TEBCdata;
 
 #define TEBC_YIELD() \
-    do {								\
-	esPtr->tosPtr = tosPtr;						\
-	TD->pc = pc;							\
-	TD->cleanup = cleanup;						\
-	TclNRAddCallback(interp, TEBCresume, TD, INT2PTR(1), NULL, NULL); \
+    do {						\
+	esPtr->tosPtr = tosPtr;				\
+	TclNRAddCallback(interp, TEBCresume,		\
+		TD, pc, INT2PTR(cleanup), NULL);	\
     } while (0)
 
 #define TEBC_DATA_DIG() \
     do {					\
-	pc = TD->pc;				\
-	cleanup = TD->cleanup;			\
 	tosPtr = esPtr->tosPtr;			\
     } while (0)
 
@@ -320,6 +315,70 @@ VarHashCreateVar(
 	}							\
     } while (0)
 
+#ifndef TCL_COMPILE_DEBUG
+#define JUMP_PEEPHOLE_F(condition, pcAdjustment, cleanup) \
+    do {								\
+	pc += (pcAdjustment);						\
+	switch (*pc) {							\
+	case INST_JUMP_FALSE1:						\
+	    NEXT_INST_F(((condition)? 2 : TclGetInt1AtPtr(pc+1)), (cleanup), 0); \
+	case INST_JUMP_TRUE1:						\
+	    NEXT_INST_F(((condition)? TclGetInt1AtPtr(pc+1) : 2), (cleanup), 0); \
+	case INST_JUMP_FALSE4:						\
+	    NEXT_INST_F(((condition)? 5 : TclGetInt4AtPtr(pc+1)), (cleanup), 0); \
+	case INST_JUMP_TRUE4:						\
+	    NEXT_INST_F(((condition)? TclGetInt4AtPtr(pc+1) : 5), (cleanup), 0); \
+	default:							\
+	    if ((condition) < 0) {					\
+		TclNewIntObj(objResultPtr, -1);				\
+	    } else {							\
+		objResultPtr = TCONST((condition) > 0);			\
+	    }								\
+	    NEXT_INST_F(0, (cleanup), 1);				\
+	}								\
+    } while (0)
+#define JUMP_PEEPHOLE_V(condition, pcAdjustment, cleanup) \
+    do {								\
+	pc += (pcAdjustment);						\
+	switch (*pc) {							\
+	case INST_JUMP_FALSE1:						\
+	    NEXT_INST_V(((condition)? 2 : TclGetInt1AtPtr(pc+1)), (cleanup), 0); \
+	case INST_JUMP_TRUE1:						\
+	    NEXT_INST_V(((condition)? TclGetInt1AtPtr(pc+1) : 2), (cleanup), 0); \
+	case INST_JUMP_FALSE4:						\
+	    NEXT_INST_V(((condition)? 5 : TclGetInt4AtPtr(pc+1)), (cleanup), 0); \
+	case INST_JUMP_TRUE4:						\
+	    NEXT_INST_V(((condition)? TclGetInt4AtPtr(pc+1) : 5), (cleanup), 0); \
+	default:							\
+	    if ((condition) < 0) {					\
+		TclNewIntObj(objResultPtr, -1);				\
+	    } else {							\
+		objResultPtr = TCONST((condition) > 0);			\
+	    }								\
+	    NEXT_INST_V(0, (cleanup), 1);				\
+	}								\
+    } while (0)
+#else /* TCL_COMPILE_DEBUG */
+#define JUMP_PEEPHOLE_F(condition, pcAdjustment, cleanup) \
+    do{									\
+	if ((condition) < 0) {						\
+	    TclNewIntObj(objResultPtr, -1);				\
+	} else {							\
+	    objResultPtr = TCONST((condition) > 0);			\
+	}								\
+	NEXT_INST_F((pcAdjustment), (cleanup), 1);			\
+    } while (0)
+#define JUMP_PEEPHOLE_V(condition, pcAdjustment, cleanup) \
+    do{									\
+	if ((condition) < 0) {						\
+	    TclNewIntObj(objResultPtr, -1);				\
+	} else {							\
+	    objResultPtr = TCONST((condition) > 0);			\
+	}								\
+	NEXT_INST_V((pcAdjustment), (cleanup), 1);			\
+    } while (0)
+#endif
+
 /*
  * Macros used to cache often-referenced Tcl evaluation stack information
  * in local variables. Note that a DECACHE_STACK_INFO()-CACHE_STACK_INFO()
@@ -385,6 +444,8 @@ VarHashCreateVar(
 	printf a;			\
 	break;				\
     }
+#   define TRACE_ERROR(interp) \
+    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
 #   define TRACE_WITH_OBJ(a, objPtr) \
     while (traceInstructions) {					\
 	fprintf(stdout, "%2d: %2d (%u) %s ", iPtr->numLevels,	\
@@ -401,6 +462,7 @@ VarHashCreateVar(
 #else /* !TCL_COMPILE_DEBUG */
 #   define TRACE(a)
 #   define TRACE_APPEND(a)
+#   define TRACE_ERROR(interp)
 #   define TRACE_WITH_OBJ(a, objPtr)
 #   define O2S(objPtr)
 #endif /* TCL_COMPILE_DEBUG */
@@ -738,7 +800,8 @@ static Tcl_Obj **	StackAllocWords(Tcl_Interp *interp, int numWords);
 static Tcl_Obj **	StackReallocWords(Tcl_Interp *interp, int numWords);
 static Tcl_NRPostProc	CopyCallback;
 static Tcl_NRPostProc	ExprObjCallback;
-
+static Tcl_NRPostProc	FinalizeOONext;
+static Tcl_NRPostProc	FinalizeOONextFilter;
 static Tcl_NRPostProc   TEBCresume;
 
 /*
@@ -1934,6 +1997,41 @@ TclIncrObj(
 /*
  *----------------------------------------------------------------------
  *
+ * ArgumentBCEnter --
+ *
+ *	This is a helper for TclNRExecuteByteCode/TEBCresume that encapsulates
+ *	a code sequence that is fairly common in the code but *not* commonly
+ *	called.
+ *
+ * Results:
+ *	None
+ *
+ * Side effects:
+ *	May register information about the bytecode in the command frame.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+ArgumentBCEnter(
+    Tcl_Interp *interp,
+    ByteCode *codePtr,
+    TEBCdata *tdPtr,
+    const unsigned char *pc,
+    int objc,
+    Tcl_Obj **objv)
+{
+    int cmd;
+
+    if (GetSrcInfoForPc(pc, codePtr, NULL, NULL, &cmd)) {
+	TclArgumentBCEnter(interp, objv, objc, codePtr, &tdPtr->cmdFrame, cmd,
+		pc - codePtr->codeStart);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * TclNRExecuteByteCode --
  *
  *	This procedure executes the instructions of a ByteCode structure. It
@@ -1966,10 +2064,6 @@ TclNRExecuteByteCode(
 		* sizeof(void *);
     int numWords = (size + sizeof(Tcl_Obj *) - 1) / sizeof(Tcl_Obj *);
 
-    if (iPtr->execEnvPtr->rewind) {
-	return TCL_ERROR;
-    }
-
     codePtr->refCount++;
 
     /*
@@ -1988,11 +2082,8 @@ TclNRExecuteByteCode(
     esPtr->tosPtr = initTosPtr;
 
     TD->codePtr     = codePtr;
-    TD->pc	    = codePtr->codeStart;
     TD->catchTop    = initCatchTop;
-    TD->cleanup     = 0;
     TD->auxObjList  = NULL;
-    TD->checkInterp = 0;
 
     /*
      * TIP #280: Initialize the frame. Do not push it yet: it will be pushed
@@ -2021,8 +2112,8 @@ TclNRExecuteByteCode(
      * Push the callback for bytecode execution
      */
 
-    TclNRAddCallback(interp, TEBCresume, TD, /*resume*/ INT2PTR(0),
-	    NULL, NULL);
+    TclNRAddCallback(interp, TEBCresume, TD, /* pc */ NULL,
+	    /* cleanup */ INT2PTR(0), NULL);
     return TCL_OK;
 }
 
@@ -2078,9 +2169,6 @@ TEBCresume(
 #define auxObjList	(TD->auxObjList)
 #define catchTop	(TD->catchTop)
 #define codePtr		(TD->codePtr)
-#define checkInterp	(TD->checkInterp)
-			/* Indicates when a check of interp readyness is
-			 * necessary. Set by CACHE_STACK_INFO() */
 
     /*
      * Globals: variables that store state, must remain valid at all times.
@@ -2088,7 +2176,8 @@ TEBCresume(
 
     Tcl_Obj **tosPtr;		/* Cached pointer to top of evaluation
 				 * stack. */
-    const unsigned char *pc;	/* The current program counter. */
+    const unsigned char *pc = data[1];
+                                /* The current program counter. */
     unsigned char inst;         /* The currently running instruction */
     
     /*
@@ -2096,8 +2185,10 @@ TEBCresume(
      * executing an instruction.
      */
 
-    int cleanup = 0;
+    int cleanup = PTR2INT(data[2]);
     Tcl_Obj *objResultPtr;
+    int checkInterp;            /* Indicates when a check of interp readyness
+				 * is necessary. Set by CACHE_STACK_INFO() */
 
     /*
      * Locals - variables that are used within opcodes or bounded sections of
@@ -2122,17 +2213,26 @@ TEBCresume(
     TEBC_DATA_DIG();
 
 #ifdef TCL_COMPILE_DEBUG
-    if (!data[1] && (tclTraceExec >= 2)) {
+    if (!pc && (tclTraceExec >= 2)) {
 	PrintByteCodeInfo(codePtr);
 	fprintf(stdout, "  Starting stack top=%d\n", (int) CURR_DEPTH);
 	fflush(stdout);
     }
 #endif
 
-    if (data[1] /* resume from invocation */) {
+    if (!pc) {
+	/* bytecode is starting from scratch */
+	checkInterp = 0;
+	pc = codePtr->codeStart;
+	goto cleanup0;
+    } else {
+        /* resume from invocation */
+	CACHE_STACK_INFO();
 	if (iPtr->execEnvPtr->rewind) {
 	    result = TCL_ERROR;
+	    goto abnormalReturn;
 	}
+
 	NRE_ASSERT(iPtr->cmdFramePtr == bcFramePtr);
 	if (bcFramePtr->cmdObj) {
 	    Tcl_DecrRefCount(bcFramePtr->cmdObj);
@@ -2141,68 +2241,49 @@ TEBCresume(
 	}
 	iPtr->cmdFramePtr = bcFramePtr->nextPtr;
 	if (iPtr->flags & INTERP_DEBUG_FRAME) {
-	    TclArgumentBCRelease((Tcl_Interp *) iPtr, bcFramePtr);
+	    TclArgumentBCRelease(interp, bcFramePtr);
 	}
 	if (codePtr->flags & TCL_BYTECODE_RECOMPILE) {
 	    iPtr->flags |= ERR_ALREADY_LOGGED;
 	    codePtr->flags &= ~TCL_BYTECODE_RECOMPILE;
 	}
 
-	CACHE_STACK_INFO();
-	if (result == TCL_OK) {
-	    /*
-	     * Push the call's object result and continue execution with the
-	     * next instruction.
-	     */
-
-	    TRACE_WITH_OBJ(("%u => ... after \"%.20s\": TCL_OK, result=",
-		    objc, cmdNameBuf), Tcl_GetObjResult(interp));
-
-	    /*
-	     * Reset the interp's result to avoid possible duplications of
-	     * large objects [Bug 781585]. We do not call Tcl_ResetResult to
-	     * avoid any side effects caused by the resetting of errorInfo and
-	     * errorCode [Bug 804681], which are not needed here. We chose
-	     * instead to manipulate the interp's object result directly.
-	     *
-	     * Note that the result object is now in objResultPtr, it keeps
-	     * the refCount it had in its role of iPtr->objResultPtr.
-	     */
-
-	    objResultPtr = Tcl_GetObjResult(interp);
-	    TclNewObj(objPtr);
-	    Tcl_IncrRefCount(objPtr);
-	    iPtr->objResultPtr = objPtr;
-#ifndef TCL_COMPILE_DEBUG
-	    if (*pc == INST_POP) {
-		TclDecrRefCount(objResultPtr);
-		NEXT_INST_V(1, cleanup, 0);
-	    }
-#endif
-	    NEXT_INST_V(0, cleanup, -1);
+	if (result != TCL_OK) {
+	    pc--;
+	    goto processExceptionReturn;
 	}
 
 	/*
-	 * Result not TCL_OK: fall through
+	 * Push the call's object result and continue execution with the next
+	 * instruction.
 	 */
-    }
 
-    if (iPtr->execEnvPtr->rewind) {
-	result = TCL_ERROR;
-	goto abnormalReturn;
-    }
+	TRACE_WITH_OBJ(("%u => ... after \"%.20s\": TCL_OK, result=",
+		objc, cmdNameBuf), Tcl_GetObjResult(interp));
 
-    if (result != TCL_OK) {
-	pc--;
-	goto processExceptionReturn;
-    }
-
-    /*
-     * Loop executing instructions until a "done" instruction, a TCL_RETURN,
-     * or some error.
-     */
+	/*
+	 * Reset the interp's result to avoid possible duplications of large
+	 * objects [Bug 781585]. We do not call Tcl_ResetResult to avoid any
+	 * side effects caused by the resetting of errorInfo and errorCode
+	 * [Bug 804681], which are not needed here. We chose instead to
+	 * manipulate the interp's object result directly.
+	 *
+	 * Note that the result object is now in objResultPtr, it keeps the
+	 * refCount it had in its role of iPtr->objResultPtr.
+	 */
 
-    goto cleanup0;
+	objResultPtr = Tcl_GetObjResult(interp);
+	TclNewObj(objPtr);
+	Tcl_IncrRefCount(objPtr);
+	iPtr->objResultPtr = objPtr;
+#ifndef TCL_COMPILE_DEBUG
+	if (*pc == INST_POP) {
+	    TclDecrRefCount(objResultPtr);
+	    NEXT_INST_V(1, cleanup, 0);
+	}
+#endif
+	NEXT_INST_V(0, cleanup, -1);
+    }
 
     /*
      * Targets for standard instruction endings; unrolled for speed in the
@@ -2413,25 +2494,93 @@ TEBCresume(
 	TRACE_APPEND(("\n"));
 	goto processExceptionReturn;
 
-    case INST_YIELD: {
-	CoroutineData *corPtr = iPtr->execEnvPtr->corPtr;
+    {
+	CoroutineData *corPtr;
+	int yieldParameter;
 
+    case INST_YIELD:
+	corPtr = iPtr->execEnvPtr->corPtr;
 	TRACE(("%.30s => ", O2S(OBJ_AT_TOS)));
 	if (!corPtr) {
 	    TRACE_APPEND(("ERROR: yield outside coroutine\n"));
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "yield can only be called in a coroutine", -1));
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ILLEGAL_YIELD",
 		    NULL);
+	    CACHE_STACK_INFO();
 	    goto gotError;
 	}
 
 #ifdef TCL_COMPILE_DEBUG
-	TRACE_WITH_OBJ(("yield, result="), iPtr->objResultPtr);
-	if (traceInstructions) {
-	    fprintf(stdout, "\n");
+	if (tclTraceExec >= 2) {
+	    if (traceInstructions) {
+		TRACE_APPEND(("YIELD...\n"));
+	    } else {
+		fprintf(stdout, "%d: (%u) yielding value \"%.30s\"\n",
+			iPtr->numLevels, (unsigned)(pc - codePtr->codeStart),
+			Tcl_GetString(OBJ_AT_TOS));
+	    }
+	    fflush(stdout);
 	}
 #endif
+	yieldParameter = 0;
+	Tcl_SetObjResult(interp, OBJ_AT_TOS);
+	goto doYield;
+
+    case INST_YIELD_TO_INVOKE:
+	corPtr = iPtr->execEnvPtr->corPtr;
+	valuePtr = OBJ_AT_TOS;
+	if (!corPtr) {
+	    TRACE(("[%.30s] => ERROR: yield outside coroutine\n",
+		    O2S(valuePtr)));
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "yieldto can only be called in a coroutine", -1));
+	    DECACHE_STACK_INFO();
+	    Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ILLEGAL_YIELD",
+		    NULL);
+	    CACHE_STACK_INFO();
+	    goto gotError;
+	}
+	if (((Namespace *)TclGetCurrentNamespace(interp))->flags & NS_DYING) {
+	    TRACE(("[%.30s] => ERROR: yield in deleted\n",
+		    O2S(valuePtr)));
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "yieldto called in deleted namespace", -1));
+	    DECACHE_STACK_INFO();
+	    Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "YIELDTO_IN_DELETED",
+		    NULL);
+	    CACHE_STACK_INFO();
+	    goto gotError;
+	}
+
+#ifdef TCL_COMPILE_DEBUG
+	if (tclTraceExec >= 2) {
+	    if (traceInstructions) {
+		TRACE(("[%.30s] => YIELD...\n", O2S(valuePtr)));
+	    } else {
+		/* FIXME: What is the right thing to trace? */
+		fprintf(stdout, "%d: (%u) yielding to [%.30s]\n",
+			iPtr->numLevels, (unsigned)(pc - codePtr->codeStart),
+			Tcl_GetString(valuePtr));
+	    }
+	    fflush(stdout);
+	}
+#endif
+
+	/*
+	 * Install a tailcall record in the caller and continue with the
+	 * yield. The yield is switched into multi-return mode (via the
+	 * 'yieldParameter').
+	 */
+
+	Tcl_IncrRefCount(valuePtr);
+	iPtr->execEnvPtr = corPtr->callerEEPtr;
+	TclSetTailcall(interp, valuePtr);
+	iPtr->execEnvPtr = corPtr->eePtr;
+	yieldParameter = (PTR2INT(NULL)+1);	/*==CORO_ACTIVATE_YIELDM*/
+
+    doYield:
 	/* TIP #280: Record the last piece of info needed by
 	 * 'TclGetSrcInfoForPc', and push the frame.
 	 */
@@ -2440,21 +2589,14 @@ TEBCresume(
 	iPtr->cmdFramePtr = bcFramePtr;
 
 	if (iPtr->flags & INTERP_DEBUG_FRAME) {
-	    int cmd;
-	    if (GetSrcInfoForPc(pc, codePtr, NULL, NULL, &cmd)) {
-		TclArgumentBCEnter((Tcl_Interp *) iPtr, objv, objc,
-			codePtr, bcFramePtr, cmd, pc - codePtr->codeStart);
-	    }
+	    ArgumentBCEnter(interp, codePtr, TD, pc, objc, objv);
 	}
 
 	pc++;
 	cleanup = 1;
 	TEBC_YIELD();
-	
-	Tcl_SetObjResult(interp, OBJ_AT_TOS);
 	TclNRAddCallback(interp, TclNRCoroutineActivateCallback, corPtr,
-		INT2PTR(0), NULL, NULL);
-
+		INT2PTR(yieldParameter), NULL, NULL);
 	return TCL_OK;
     }
 
@@ -2467,11 +2609,14 @@ TEBCresume(
 	    TRACE(("%d => ERROR: tailcall in non-proc context\n", opnd));
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "tailcall can only be called from a proc or lambda", -1));
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "TAILCALL", "ILLEGAL", NULL);
+	    CACHE_STACK_INFO();
 	    goto gotError;
 	}
 
 #ifdef TCL_COMPILE_DEBUG
+	/* FIXME: What is the right thing to trace? */
 	{
 	    register int i;
 
@@ -2545,7 +2690,7 @@ TEBCresume(
     case INST_OVER:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	objResultPtr = OBJ_AT_DEPTH(opnd);
-	TRACE_WITH_OBJ(("=> "), objResultPtr);
+	TRACE_WITH_OBJ(("%u => ", opnd), objResultPtr);
 	NEXT_INST_F(5, 0, 1);
 
     case INST_REVERSE: {
@@ -2560,10 +2705,11 @@ TEBCresume(
 	    *b = tmpPtr;
 	    a++; b--;
 	}
+	TRACE(("%u => OK\n", opnd));
 	NEXT_INST_F(5, 0, 0);
     }
 
-    case INST_CONCAT1: {
+    case INST_STR_CONCAT1: {
 	int appendLen = 0;
 	char *bytes, *p;
 	Tcl_Obj **currPtr;
@@ -2712,6 +2858,17 @@ TEBCresume(
 	NEXT_INST_V(2, opnd, 1);
     }
 
+    case INST_CONCAT_STK:
+	/*
+	 * Pop the opnd (objc) top stack elements, run through Tcl_ConcatObj,
+	 * and then decrement their ref counts.
+	 */
+
+	opnd = TclGetUInt4AtPtr(pc+1);
+	objResultPtr = Tcl_ConcatObj(opnd, &OBJ_AT_DEPTH(opnd-1));
+	TRACE_WITH_OBJ(("%u => ", opnd), objResultPtr);
+	NEXT_INST_V(5, opnd, 1);
+
     case INST_EXPAND_START:
 	/*
 	 * Push an element to the auxObjList. This records the current
@@ -2730,6 +2887,7 @@ TEBCresume(
 	objPtr->internalRep.ptrAndLongRep.value = CURR_DEPTH;
 	objPtr->length = 0;
 	PUSH_TAUX_OBJ(objPtr);
+	TRACE(("=> mark depth as %d\n", (int) CURR_DEPTH));
 	NEXT_INST_F(1, 0, 0);
 
     case INST_EXPAND_DROP:
@@ -2746,6 +2904,7 @@ TEBCresume(
 	/* Ugly abuse! */
 	starting = 1;
 #endif
+	TRACE(("=> drop %d items\n", objc));
 	NEXT_INST_V(1, objc, 0);
 
     case INST_EXPAND_STKTOP: {
@@ -2759,9 +2918,9 @@ TEBCresume(
 	 */
 
 	objPtr = OBJ_AT_TOS;
+	TRACE(("\"%.30s\" => ", O2S(objPtr)));
 	if (TclListObjGetElements(interp, objPtr, &objc, &objv) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%.30s => ERROR: ", O2S(objPtr)),
-		    Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	(void) POP_OBJECT();
@@ -2805,6 +2964,7 @@ TEBCresume(
 	    PUSH_OBJECT(objv[i]);
 	}
 
+	TRACE_APPEND(("OK\n"));
 	Tcl_DecrRefCount(objPtr);
 	NEXT_INST_F(5, 0, 0);
     }
@@ -2897,11 +3057,7 @@ TEBCresume(
 	iPtr->cmdFramePtr = bcFramePtr;
 
 	if (iPtr->flags & INTERP_DEBUG_FRAME) {
-	    int cmd;
-	    if (GetSrcInfoForPc(pc, codePtr, NULL, NULL, &cmd)) {
-		TclArgumentBCEnter((Tcl_Interp *) iPtr, objv, objc,
-			codePtr, bcFramePtr, cmd, pc - codePtr->codeStart);
-	    }
+	    ArgumentBCEnter(interp, codePtr, TD, pc, objc, objv);
 	}
 
 	DECACHE_STACK_INFO();
@@ -3046,11 +3202,7 @@ TEBCresume(
 	bcFramePtr->data.tebc.pc = (char *) pc;
 	iPtr->cmdFramePtr = bcFramePtr;
 	if (iPtr->flags & INTERP_DEBUG_FRAME) {
-	    int cmd;
-	    if (GetSrcInfoForPc(pc, codePtr, NULL, NULL, &cmd)) {
-		TclArgumentBCEnter((Tcl_Interp *) iPtr, objv, objc,
-			codePtr, bcFramePtr, cmd, pc - codePtr->codeStart);
-	    }
+	    ArgumentBCEnter(interp, codePtr, TD, pc, objc, objv);
 	}
 	iPtr->ensembleRewrite.sourceObjs = objv;
 	iPtr->ensembleRewrite.numRemovedObjs = opnd;
@@ -3149,7 +3301,7 @@ TEBCresume(
 	varPtr = TclLookupArrayElement(interp, part1Ptr, part2Ptr,
 		TCL_LEAVE_ERR_MSG, "read", 0, 1, arrayPtr, opnd);
 	if (varPtr == NULL) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	cleanup = 1;
@@ -3175,7 +3327,7 @@ TEBCresume(
 		TCL_LEAVE_ERR_MSG, "read", /*createPart1*/0, /*createPart2*/1,
 		&arrayPtr);
 	if (!varPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -3202,7 +3354,7 @@ TEBCresume(
 		part1Ptr, part2Ptr, TCL_LEAVE_ERR_MSG, opnd);
 	CACHE_STACK_INFO();
 	if (!objResultPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
@@ -3351,7 +3503,7 @@ TEBCresume(
 	varPtr = TclObjLookupVarEx(interp, objPtr,part2Ptr, TCL_LEAVE_ERR_MSG,
 		"set", /*createPart1*/ 1, /*createPart2*/ 1, &arrayPtr);
 	if (!varPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	cleanup = ((part2Ptr == NULL)? 2 : 3);
@@ -3401,7 +3553,7 @@ TEBCresume(
 	varPtr = TclLookupArrayElement(interp, part1Ptr, part2Ptr,
 		TCL_LEAVE_ERR_MSG, "set", 1, 1, arrayPtr, opnd);
 	if (!varPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	goto doCallPtrSetVar;
@@ -3449,7 +3601,7 @@ TEBCresume(
 		part1Ptr, part2Ptr, valuePtr, storeFlags, opnd);
 	CACHE_STACK_INFO();
 	if (!objResultPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 #ifndef TCL_COMPILE_DEBUG
@@ -3524,9 +3676,11 @@ TEBCresume(
 	varPtr = TclObjLookupVarEx(interp, objPtr, part2Ptr,
 		TCL_LEAVE_ERR_MSG, "read", 1, 1, &arrayPtr);
 	if (!varPtr) {
+	    DECACHE_STACK_INFO();
 	    Tcl_AddErrorInfo(interp,
 		    "\n    (reading value of variable to increment)");
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    CACHE_STACK_INFO();
+	    TRACE_ERROR(interp);
 	    Tcl_DecrRefCount(incrPtr);
 	    goto gotError;
 	}
@@ -3552,7 +3706,7 @@ TEBCresume(
 	varPtr = TclLookupArrayElement(interp, part1Ptr, part2Ptr,
 		TCL_LEAVE_ERR_MSG, "read", 1, 1, arrayPtr, opnd);
 	if (!varPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    Tcl_DecrRefCount(incrPtr);
 	    goto gotError;
 	}
@@ -3664,8 +3818,7 @@ TEBCresume(
 	    TclNewLongObj(incrPtr, increment);
 	    if (TclIncrObj(interp, objResultPtr, incrPtr) != TCL_OK) {
 		Tcl_DecrRefCount(incrPtr);
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    Tcl_DecrRefCount(incrPtr);
@@ -3702,8 +3855,7 @@ TEBCresume(
 	    }
 	    if (TclIncrObj(interp, objResultPtr, incrPtr) != TCL_OK) {
 		Tcl_DecrRefCount(incrPtr);
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    Tcl_DecrRefCount(incrPtr);
@@ -3714,8 +3866,7 @@ TEBCresume(
 	    CACHE_STACK_INFO();
 	    Tcl_DecrRefCount(incrPtr);
 	    if (objResultPtr == NULL) {
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
@@ -3736,6 +3887,8 @@ TEBCresume(
      */
 
     case INST_EXIST_SCALAR:
+	cleanup = 0;
+	pcAdjustment = 5;
 	opnd = TclGetUInt4AtPtr(pc+1);
 	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
@@ -3752,16 +3905,11 @@ TEBCresume(
 		varPtr = NULL;
 	    }
 	}
-
-	/*
-	 * Tricky! Arrays always exist.
-	 */
-
-	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-	NEXT_INST_F(5, 0, 1);
+	goto afterExistsPeephole;
 
     case INST_EXIST_ARRAY:
+	cleanup = 1;
+	pcAdjustment = 5;
 	opnd = TclGetUInt4AtPtr(pc+1);
 	part2Ptr = OBJ_AT_TOS;
 	arrayPtr = LOCAL(opnd);
@@ -3772,7 +3920,7 @@ TEBCresume(
 	if (TclIsVarArray(arrayPtr) && !ReadTraced(arrayPtr)) {
 	    varPtr = VarHashFindVar(arrayPtr->value.tablePtr, part2Ptr);
 	    if (!varPtr || !ReadTraced(varPtr)) {
-		goto doneExistArray;
+		goto afterExistsPeephole;
 	    }
 	}
 	varPtr = TclLookupArrayElement(interp, NULL, part2Ptr, 0, "access",
@@ -3789,13 +3937,11 @@ TEBCresume(
 		varPtr = NULL;
 	    }
 	}
-    doneExistArray:
-	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-	NEXT_INST_F(5, 1, 1);
+	goto afterExistsPeephole;
 
     case INST_EXIST_ARRAY_STK:
 	cleanup = 2;
+	pcAdjustment = 1;
 	part2Ptr = OBJ_AT_TOS;		/* element name */
 	part1Ptr = OBJ_UNDER_TOS;	/* array name */
 	TRACE(("\"%.30s(%.30s)\" => ", O2S(part1Ptr), O2S(part2Ptr)));
@@ -3803,6 +3949,7 @@ TEBCresume(
 
     case INST_EXIST_STK:
 	cleanup = 1;
+	pcAdjustment = 1;
 	part2Ptr = NULL;
 	part1Ptr = OBJ_AT_TOS;		/* variable name */
 	TRACE(("\"%.30s\" => ", O2S(part1Ptr)));
@@ -3822,9 +3969,17 @@ TEBCresume(
 		varPtr = NULL;
 	    }
 	}
-	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-	NEXT_INST_V(1, cleanup, 1);
+
+	/*
+	 * Peep-hole optimisation: if you're about to jump, do jump from here.
+	 */
+
+    afterExistsPeephole: {
+	int found = (varPtr && !TclIsVarUndefined(varPtr));
+
+	TRACE_APPEND(("%d\n", found ? 1 : 0));
+	JUMP_PEEPHOLE_V(found, pcAdjustment, cleanup);
+    }
 
     /*
      *	   End of INST_EXIST instructions.
@@ -3842,7 +3997,7 @@ TEBCresume(
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
-	TRACE(("%s %u\n", (flags?"normal":"noerr"), opnd));
+	TRACE(("%s %u => ", (flags ? "normal" : "noerr"), opnd));
 	if (TclIsVarDirectUnsettable(varPtr) && !TclIsVarInHash(varPtr)) {
 	    /*
 	     * No errors, no traces, no searches: just make the variable cease
@@ -3855,6 +4010,7 @@ TEBCresume(
 		goto slowUnsetScalar;
 	    }
 	    varPtr->value.objPtr = NULL;
+	    TRACE_APPEND(("OK\n"));
 	    NEXT_INST_F(6, 0, 0);
 	}
 
@@ -3875,7 +4031,7 @@ TEBCresume(
 	while (TclIsVarLink(arrayPtr)) {
 	    arrayPtr = arrayPtr->value.linkPtr;
 	}
-	TRACE(("%s %u \"%.30s\"\n",
+	TRACE(("%s %u \"%.30s\" => ",
 		(flags ? "normal" : "noerr"), opnd, O2S(part2Ptr)));
 	if (TclIsVarArray(arrayPtr) && !UnsetTraced(arrayPtr)) {
 	    varPtr = VarHashFindVar(arrayPtr->value.tablePtr, part2Ptr);
@@ -3891,12 +4047,14 @@ TEBCresume(
 		    goto slowUnsetArray;
 		}
 		varPtr->value.objPtr = NULL;
+		TRACE_APPEND(("OK\n"));
 		NEXT_INST_F(6, 1, 0);
 	    } else if (!varPtr && !(flags & TCL_LEAVE_ERR_MSG)) {
 		/*
 		 * Don't need to do anything here.
 		 */
 
+		TRACE_APPEND(("OK\n"));
 		NEXT_INST_F(6, 1, 0);
 	    }
 	}
@@ -3920,7 +4078,7 @@ TEBCresume(
 	cleanup = 2;
 	part2Ptr = OBJ_AT_TOS;		/* element name */
 	part1Ptr = OBJ_UNDER_TOS;	/* array name */
-	TRACE(("%s \"%.30s(%.30s)\"\n", (flags?"normal":"noerr"),
+	TRACE(("%s \"%.30s(%.30s)\" => ", (flags ? "normal" : "noerr"),
 		O2S(part1Ptr), O2S(part2Ptr)));
 	goto doUnsetStk;
 
@@ -3929,7 +4087,8 @@ TEBCresume(
 	cleanup = 1;
 	part2Ptr = NULL;
 	part1Ptr = OBJ_AT_TOS;		/* variable name */
-	TRACE(("%s \"%.30s\"\n", (flags?"normal":"noerr"), O2S(part1Ptr)));
+	TRACE(("%s \"%.30s\" => ", (flags ? "normal" : "noerr"),
+		O2S(part1Ptr)));
 
     doUnsetStk:
 	DECACHE_STACK_INFO();
@@ -3938,11 +4097,12 @@ TEBCresume(
 	    goto errorInUnset;
 	}
 	CACHE_STACK_INFO();
+	TRACE_APPEND(("OK\n"));
 	NEXT_INST_V(2, cleanup, 0);
 
     errorInUnset:
 	CACHE_STACK_INFO();
-	TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	TRACE_ERROR(interp);
 	goto gotError;
 
 	/*
@@ -3951,7 +4111,7 @@ TEBCresume(
 
     case INST_DICT_DONE:
 	opnd = TclGetUInt4AtPtr(pc+1);
-	TRACE(("%u\n", opnd));
+	TRACE(("%u => OK\n", opnd));
 	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
@@ -4004,8 +4164,7 @@ TEBCresume(
 		    TCL_GLOBAL_ONLY|TCL_TRACE_ARRAY), 1, opnd);
 	    CACHE_STACK_INFO();
 	    if (result == TCL_ERROR) {
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
@@ -4038,7 +4197,7 @@ TEBCresume(
 	varPtr = TclObjLookupVarEx(interp, part1Ptr, NULL, TCL_LEAVE_ERR_MSG,
 		"set", /*createPart1*/1, /*createPart2*/0, &arrayPtr);
 	if (varPtr == NULL) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
     doArrayMake:
@@ -4050,9 +4209,10 @@ TEBCresume(
 
 		TclObjVarErrMsg(interp, part1Ptr, NULL, "array set",
 			"variable isn't array", opnd);
+		DECACHE_STACK_INFO();
 		Tcl_SetErrorCode(interp, "TCL", "WRITE", "ARRAY", NULL);
-		TRACE_APPEND(("ERROR: bad array ref: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		CACHE_STACK_INFO();
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    TclSetVarArray(varPtr);
@@ -4080,9 +4240,11 @@ TEBCresume(
 	Namespace *savedNsPtr;
 
     case INST_UPVAR:
-	TRACE_WITH_OBJ(("upvar "), OBJ_UNDER_TOS);
+	TRACE(("%d %.30s %.30s => ", TclGetInt4AtPtr(pc+1),
+		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS)));
 
 	if (TclObjGetFrame(interp, OBJ_UNDER_TOS, &framePtr) == -1) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4097,13 +4259,16 @@ TEBCresume(
 		/*createPart2*/ 1, &varPtr);
 	iPtr->varFramePtr = savedFramePtr;
 	if (!otherPtr) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	goto doLinkVars;
 
     case INST_NSUPVAR:
-	TRACE_WITH_OBJ(("nsupvar "), OBJ_UNDER_TOS);
+	TRACE(("%d %.30s %.30s => ", TclGetInt4AtPtr(pc+1),
+		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS)));
 	if (TclGetNamespaceFromObj(interp, OBJ_UNDER_TOS, &nsPtr) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4118,16 +4283,18 @@ TEBCresume(
 		/*createPart1*/ 1, /*createPart2*/ 1, &varPtr);
 	iPtr->varFramePtr->nsPtr = savedNsPtr;
 	if (!otherPtr) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	goto doLinkVars;
 
     case INST_VARIABLE:
-	TRACE(("variable "));
+	TRACE(("%d, %.30s => ", TclGetInt4AtPtr(pc+1), O2S(OBJ_AT_TOS)));
 	otherPtr = TclObjLookupVarEx(interp, OBJ_AT_TOS, NULL,
 		(TCL_NAMESPACE_ONLY | TCL_LEAVE_ERR_MSG), "access",
 		/*createPart1*/ 1, /*createPart2*/ 1, &varPtr);
 	if (!otherPtr) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4145,7 +4312,7 @@ TEBCresume(
 	 * if there are no errors; otherwise, let it handle the case.
 	 */
 
-	opnd = TclGetInt4AtPtr(pc+1);;
+	opnd = TclGetInt4AtPtr(pc+1);
 	varPtr = LOCAL(opnd);
 	if ((varPtr != otherPtr) && !TclIsVarTraced(varPtr)
 		&& (TclIsVarUndefined(varPtr) || TclIsVarLink(varPtr))) {
@@ -4157,6 +4324,7 @@ TEBCresume(
 		Var *linkPtr = varPtr->value.linkPtr;
 
 		if (linkPtr == otherPtr) {
+		    TRACE_APPEND(("already linked\n"));
 		    NEXT_INST_F(5, 1, 0);
 		}
 		if (TclIsVarInHash(linkPtr)) {
@@ -4173,6 +4341,7 @@ TEBCresume(
 	    }
 	} else if (TclPtrObjMakeUpvar(interp, otherPtr, NULL, 0,
 		opnd) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4181,6 +4350,7 @@ TEBCresume(
 	 * variables - and [variable] did not push it at all.
 	 */
 
+	TRACE_APPEND(("link made\n"));
 	NEXT_INST_F(5, 1, 0);
     }
 
@@ -4227,31 +4397,29 @@ TEBCresume(
 
     doCondJump:
 	valuePtr = OBJ_AT_TOS;
+	TRACE(("%d => ", jmpOffset[
+		(*pc==INST_JUMP_FALSE1 || *pc==INST_JUMP_FALSE4) ? 0 : 1]));
 
 	/* TODO - check claim that taking address of b harms performance */
 	/* TODO - consider optimization search for constants */
 	if (TclGetBooleanFromObj(interp, valuePtr, &b) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%d => ERROR: ", jmpOffset[
-		    ((*pc == INST_JUMP_FALSE1) || (*pc == INST_JUMP_FALSE4))
-		    ? 0 : 1]), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
 #ifdef TCL_COMPILE_DEBUG
 	if (b) {
 	    if ((*pc == INST_JUMP_TRUE1) || (*pc == INST_JUMP_TRUE4)) {
-		TRACE(("%d => %.20s true, new pc %u\n", jmpOffset[1],
-			O2S(valuePtr),
+		TRACE_APPEND(("%.20s true, new pc %u\n", O2S(valuePtr),
 			(unsigned)(pc + jmpOffset[1] - codePtr->codeStart)));
 	    } else {
-		TRACE(("%d => %.20s true\n", jmpOffset[0], O2S(valuePtr)));
+		TRACE_APPEND(("%.20s true\n", O2S(valuePtr)));
 	    }
 	} else {
 	    if ((*pc == INST_JUMP_TRUE1) || (*pc == INST_JUMP_TRUE4)) {
-		TRACE(("%d => %.20s false\n", jmpOffset[0], O2S(valuePtr)));
+		TRACE_APPEND(("%.20s false\n", O2S(valuePtr)));
 	    } else {
-		TRACE(("%d => %.20s false, new pc %u\n", jmpOffset[0],
-			O2S(valuePtr),
+		TRACE_APPEND(("%.20s false, new pc %u\n", O2S(valuePtr),
 			(unsigned)(pc + jmpOffset[0] - codePtr->codeStart)));
 	    }
 	}
@@ -4270,7 +4438,7 @@ TEBCresume(
 
 	opnd = TclGetInt4AtPtr(pc+1);
 	jtPtr = (JumptableInfo *) codePtr->auxDataArrayPtr[opnd].clientData;
-	TRACE(("%d => %.20s ", opnd, O2S(OBJ_AT_TOS)));
+	TRACE(("%d \"%.20s\" => ", opnd, O2S(OBJ_AT_TOS)));
 	hPtr = Tcl_FindHashEntry(&jtPtr->hashTable, TclGetString(OBJ_AT_TOS));
 	if (hPtr != NULL) {
 	    int jumpOffset = PTR2INT(Tcl_GetHashValue(hPtr));
@@ -4365,13 +4533,11 @@ TEBCresume(
 	register CallFrame *framePtr = iPtr->varFramePtr;
 	register CallFrame *rootFramePtr = iPtr->rootFramePtr;
 
-	valuePtr = OBJ_AT_TOS;
-	if (TclGetIntFromObj(interp, valuePtr, &level) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%.30s => ERROR: ", O2S(valuePtr)),
-		    Tcl_GetObjResult(interp));
+	TRACE(("\"%.30s\" => ", O2S(OBJ_AT_TOS)));
+	if (TclGetIntFromObj(interp, OBJ_AT_TOS, &level) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
-	TRACE(("%d => ", level));
 	if (level <= 0) {
 	    level += framePtr->level;
 	}
@@ -4380,38 +4546,76 @@ TEBCresume(
 	    /* Empty loop body */
 	}
 	if (framePtr == rootFramePtr) {
-	    Tcl_AppendResult(interp, "bad level \"", TclGetString(valuePtr),
-		    "\"", NULL);
-	    TRACE_APPEND(("ERROR: bad level\n"));
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad level \"%s\"", TclGetString(OBJ_AT_TOS)));
+	    TRACE_ERROR(interp);
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "STACK_LEVEL",
-		    TclGetString(valuePtr), NULL);
+		    TclGetString(OBJ_AT_TOS), NULL);
+	    CACHE_STACK_INFO();
 	    goto gotError;
 	}
 	objResultPtr = Tcl_NewListObj(framePtr->objc, framePtr->objv);
 	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 1, 1);
     }
-    case INST_RESOLVE_COMMAND: {
-	Tcl_Command cmd = Tcl_GetCommandFromObj(interp, OBJ_AT_TOS);
+    {
+	Tcl_Command cmd, origCmd;
 
+    case INST_RESOLVE_COMMAND:
+	cmd = Tcl_GetCommandFromObj(interp, OBJ_AT_TOS);
 	TclNewObj(objResultPtr);
 	if (cmd != NULL) {
 	    Tcl_GetCommandFullName(interp, cmd, objResultPtr);
 	}
 	TRACE_WITH_OBJ(("\"%.20s\" => ", O2S(OBJ_AT_TOS)), objResultPtr);
 	NEXT_INST_F(1, 1, 1);
+
+    case INST_ORIGIN_COMMAND:
+	TRACE(("\"%.30s\" => ", O2S(OBJ_AT_TOS)));
+	cmd = Tcl_GetCommandFromObj(interp, OBJ_AT_TOS);
+	if (cmd == NULL) {
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "invalid command name \"%s\"", TclGetString(OBJ_AT_TOS)));
+	    DECACHE_STACK_INFO();
+	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND",
+		    TclGetString(OBJ_AT_TOS), NULL);
+	    CACHE_STACK_INFO();
+	    TRACE_APPEND(("ERROR: not command\n"));
+	    goto gotError;
+	}
+	origCmd = TclGetOriginalCommand(cmd);
+	if (origCmd == NULL) {
+	    origCmd = cmd;
+	}
+	TclNewObj(objResultPtr);
+	Tcl_GetCommandFullName(interp, origCmd, objResultPtr);
+	TRACE_APPEND(("\"%.30s\"", O2S(OBJ_AT_TOS)));
+	NEXT_INST_F(1, 1, 1);
     }
-    case INST_TCLOO_SELF: {
-	CallFrame *framePtr = iPtr->varFramePtr;
+
+    /*
+     * -----------------------------------------------------------------
+     *	   Start of TclOO support instructions.
+     */
+
+    {
+	Object *oPtr;
+	CallFrame *framePtr;
 	CallContext *contextPtr;
+	int skip, newDepth;
 
+    case INST_TCLOO_SELF:
+	framePtr = iPtr->varFramePtr;
 	if (framePtr == NULL ||
 		!(framePtr->isProcCallFrame & FRAME_IS_METHOD)) {
 	    TRACE(("=> ERROR: no TclOO call context\n"));
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "self may only be called from inside a method",
 		    -1));
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "CONTEXT_REQUIRED", NULL);
+	    CACHE_STACK_INFO();
 	    goto gotError;
 	}
 	contextPtr = framePtr->clientData;
@@ -4423,9 +4627,212 @@ TEBCresume(
 	objResultPtr = TclOOObjectName(interp, contextPtr->oPtr);
 	TRACE_WITH_OBJ(("=> "), objResultPtr);
 	NEXT_INST_F(1, 0, 1);
-    }
-    {
-	Object *oPtr;
+
+    case INST_TCLOO_NEXT_CLASS:
+	opnd = TclGetUInt1AtPtr(pc+1);
+	framePtr = iPtr->varFramePtr;
+	valuePtr = OBJ_AT_DEPTH(opnd - 2);
+	objv = &OBJ_AT_DEPTH(opnd - 1);
+	skip = 2;
+	TRACE(("%d => ", opnd));
+	if (framePtr == NULL ||
+		!(framePtr->isProcCallFrame & FRAME_IS_METHOD)) {
+	    TRACE_APPEND(("ERROR: no TclOO call context\n"));
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "nextto may only be called from inside a method",
+		    -1));
+	    DECACHE_STACK_INFO();
+	    Tcl_SetErrorCode(interp, "TCL", "OO", "CONTEXT_REQUIRED", NULL);
+	    CACHE_STACK_INFO();
+	    goto gotError;
+	}
+	contextPtr = framePtr->clientData;
+
+	oPtr = (Object *) Tcl_GetObjectFromObj(interp, valuePtr);
+	if (oPtr == NULL) {
+	    TRACE_APPEND(("ERROR: \"%.30s\" not object\n", O2S(valuePtr)));
+	    goto gotError;
+	} else {
+	    Class *classPtr = oPtr->classPtr;
+	    struct MInvoke *miPtr;
+	    int i;
+	    const char *methodType;
+
+	    if (classPtr == NULL) {
+		TRACE_APPEND(("ERROR: \"%.30s\" not class\n", O2S(valuePtr)));
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"\"%s\" is not a class", TclGetString(valuePtr)));
+		DECACHE_STACK_INFO();
+		Tcl_SetErrorCode(interp, "TCL", "OO", "CLASS_REQUIRED", NULL);
+		CACHE_STACK_INFO();
+		goto gotError;
+	    }
+
+	    for (i=contextPtr->index+1 ; i<contextPtr->callPtr->numChain ; i++) {
+		miPtr = contextPtr->callPtr->chain + i;
+		if (!miPtr->isFilter &&
+			miPtr->mPtr->declaringClassPtr == classPtr) {
+		    newDepth = i;
+#ifdef TCL_COMPILE_DEBUG
+		    if (tclTraceExec >= 2) {
+			if (traceInstructions) {
+			    strncpy(cmdNameBuf, TclGetString(objv[0]), 20);
+			} else {
+			    fprintf(stdout, "%d: (%u) invoking ",
+				    iPtr->numLevels,
+				    (unsigned)(pc - codePtr->codeStart));
+			}
+			for (i = 0;  i < opnd;  i++) {
+			    TclPrintObject(stdout, objv[i], 15);
+			    fprintf(stdout, " ");
+			}
+			fprintf(stdout, "\n");
+			fflush(stdout);
+		    }
+#endif /*TCL_COMPILE_DEBUG*/
+		    goto doInvokeNext;
+		}
+	    }
+
+	    if (contextPtr->callPtr->flags & CONSTRUCTOR) {
+		methodType = "constructor";
+	    } else if (contextPtr->callPtr->flags & DESTRUCTOR) {
+		methodType = "destructor";
+	    } else {
+		methodType = "method";
+	    }
+
+	    TRACE_APPEND(("ERROR: \"%.30s\" not on reachable chain\n",
+		    O2S(valuePtr)));
+	    for (i=contextPtr->index ; i>=0 ; i--) {
+		miPtr = contextPtr->callPtr->chain + i;
+		if (miPtr->isFilter
+			|| miPtr->mPtr->declaringClassPtr != classPtr) {
+		    continue;
+		}
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"%s implementation by \"%s\" not reachable from here",
+			methodType, TclGetString(valuePtr)));
+		DECACHE_STACK_INFO();
+		Tcl_SetErrorCode(interp, "TCL", "OO", "CLASS_NOT_REACHABLE",
+			NULL);
+		CACHE_STACK_INFO();
+		goto gotError;
+	    }
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "%s has no non-filter implementation by \"%s\"",
+		    methodType, TclGetString(valuePtr)));
+	    DECACHE_STACK_INFO();
+	    Tcl_SetErrorCode(interp, "TCL", "OO", "CLASS_NOT_THERE", NULL);
+	    CACHE_STACK_INFO();
+	    goto gotError;
+	}
+
+    case INST_TCLOO_NEXT:
+	opnd = TclGetUInt1AtPtr(pc+1);
+	objv = &OBJ_AT_DEPTH(opnd - 1);
+	framePtr = iPtr->varFramePtr;
+	skip = 1;
+	TRACE(("%d => ", opnd));
+	if (framePtr == NULL ||
+		!(framePtr->isProcCallFrame & FRAME_IS_METHOD)) {
+	    TRACE_APPEND(("ERROR: no TclOO call context\n"));
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "next may only be called from inside a method",
+		    -1));
+	    DECACHE_STACK_INFO();
+	    Tcl_SetErrorCode(interp, "TCL", "OO", "CONTEXT_REQUIRED", NULL);
+	    CACHE_STACK_INFO();
+	    goto gotError;
+	}
+	contextPtr = framePtr->clientData;
+
+	newDepth = contextPtr->index + 1;
+	if (newDepth >= contextPtr->callPtr->numChain) {
+	    /*
+	     * We're at the end of the chain; generate an error message unless
+	     * the interpreter is being torn down, in which case we might be
+	     * getting here because of methods/destructors doing a [next] (or
+	     * equivalent) unexpectedly.
+	     */
+
+	    const char *methodType;
+
+	    if (contextPtr->callPtr->flags & CONSTRUCTOR) {
+		methodType = "constructor";
+	    } else if (contextPtr->callPtr->flags & DESTRUCTOR) {
+		methodType = "destructor";
+	    } else {
+		methodType = "method";
+	    }
+
+	    TRACE_APPEND(("ERROR: no TclOO next impl\n"));
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "no next %s implementation", methodType));
+	    DECACHE_STACK_INFO();
+	    Tcl_SetErrorCode(interp, "TCL", "OO", "NOTHING_NEXT", NULL);
+	    CACHE_STACK_INFO();
+	    goto gotError;
+#ifdef TCL_COMPILE_DEBUG
+	} else if (tclTraceExec >= 2) {
+	    int i;
+
+	    if (traceInstructions) {
+		strncpy(cmdNameBuf, TclGetString(objv[0]), 20);
+	    } else {
+		fprintf(stdout, "%d: (%u) invoking ",
+			iPtr->numLevels, (unsigned)(pc - codePtr->codeStart));
+	    }
+	    for (i = 0;  i < opnd;  i++) {
+		TclPrintObject(stdout, objv[i], 15);
+		fprintf(stdout, " ");
+	    }
+	    fprintf(stdout, "\n");
+	    fflush(stdout);
+#endif /*TCL_COMPILE_DEBUG*/
+	}
+
+    doInvokeNext:
+	bcFramePtr->data.tebc.pc = (char *) pc;
+	iPtr->cmdFramePtr = bcFramePtr;
+
+	if (iPtr->flags & INTERP_DEBUG_FRAME) {
+	    ArgumentBCEnter(interp, codePtr, TD, pc, opnd, objv);
+	}
+
+	pcAdjustment = 2;
+	cleanup = opnd;
+	DECACHE_STACK_INFO();
+	iPtr->varFramePtr = framePtr->callerVarPtr;
+	pc += pcAdjustment;
+	TEBC_YIELD();
+
+	oPtr = contextPtr->oPtr;
+	if (oPtr->flags & FILTER_HANDLING) {
+	    TclNRAddCallback(interp, FinalizeOONextFilter,
+		    framePtr, contextPtr, INT2PTR(contextPtr->index),
+		    INT2PTR(contextPtr->skip));
+	} else {
+	    TclNRAddCallback(interp, FinalizeOONext,
+		    framePtr, contextPtr, INT2PTR(contextPtr->index),
+		    INT2PTR(contextPtr->skip));
+	}
+	contextPtr->skip = skip;
+	contextPtr->index = newDepth;
+	if (contextPtr->callPtr->chain[newDepth].isFilter
+		|| contextPtr->callPtr->flags & FILTER_HANDLING) {
+	    oPtr->flags |= FILTER_HANDLING;
+	} else {
+	    oPtr->flags &= ~FILTER_HANDLING;
+	}
+
+	{
+	    register Method *const mPtr =
+		    contextPtr->callPtr->chain[newDepth].mPtr;
+
+	    return mPtr->typePtr->callProc(mPtr->clientData, interp,
+		    (Tcl_ObjectContext) contextPtr, opnd, objv);
+	}
 
     case INST_TCLOO_IS_OBJECT:
 	oPtr = (Object *) Tcl_GetObjectFromObj(interp, OBJ_AT_TOS);
@@ -4459,6 +4866,7 @@ TEBCresume(
     }
 
     /*
+     *     End of TclOO support instructions.
      * -----------------------------------------------------------------
      *	   Start of INST_LIST and related instructions.
      */
@@ -4480,19 +4888,19 @@ TEBCresume(
 	NEXT_INST_V(5, opnd, 1);
 
     case INST_LIST_LENGTH:
-	valuePtr = OBJ_AT_TOS;
-	if (TclListObjLength(interp, valuePtr, &length) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%.30s => ERROR: ", O2S(valuePtr)),
-		    Tcl_GetObjResult(interp));
+	TRACE(("\"%.30s\" => ", O2S(OBJ_AT_TOS)));
+	if (TclListObjLength(interp, OBJ_AT_TOS, &length) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TclNewIntObj(objResultPtr, length);
-	TRACE(("%.20s => %d\n", O2S(valuePtr), length));
+	TRACE_APPEND(("%d\n", length));
 	NEXT_INST_F(1, 1, 1);
 
     case INST_LIST_INDEX:	/* lindex with objc == 3 */
 	value2Ptr = OBJ_AT_TOS;
 	valuePtr = OBJ_UNDER_TOS;
+	TRACE(("\"%.30s\" \"%.30s\" => ", O2S(valuePtr), O2S(value2Ptr)));
 
 	/*
 	 * Extract the desired list element.
@@ -4510,8 +4918,7 @@ TEBCresume(
 
 	objResultPtr = TclLindexList(interp, valuePtr, value2Ptr);
 	if (!objResultPtr) {
-	    TRACE_WITH_OBJ(("%.30s %.30s => ERROR: ", O2S(valuePtr),
-		    O2S(value2Ptr)), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4519,8 +4926,7 @@ TEBCresume(
 	 * Stash the list element on the stack.
 	 */
 
-	TRACE(("%.20s %.20s => %s\n",
-		O2S(valuePtr), O2S(value2Ptr), O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 2, -1);	/* Already has the correct refCount */
 
     case INST_LIST_INDEX_IMM:	/* lindex with objc==3 and index in bytecode
@@ -4532,6 +4938,7 @@ TEBCresume(
 
 	valuePtr = OBJ_AT_TOS;
 	opnd = TclGetInt4AtPtr(pc+1);
+	TRACE(("\%.30s\" %d => ", O2S(valuePtr), opnd));
 
 	/*
 	 * Get the contents of the list, making sure that it really is a list
@@ -4539,8 +4946,7 @@ TEBCresume(
 	 */
 
 	if (TclListObjGetElements(interp, valuePtr, &objc, &objv) != TCL_OK) {
-	    TRACE_WITH_OBJ(("\"%.30s\" %d => ERROR: ", O2S(valuePtr), opnd),
-		    Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4563,8 +4969,7 @@ TEBCresume(
 	    TclNewObj(objResultPtr);
 	}
 
-	TRACE_WITH_OBJ(("\"%.30s\" %d => ", O2S(valuePtr), opnd),
-		objResultPtr);
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(pcAdjustment, 1, 1);
 
     case INST_LIST_INDEX_MULTI:	/* 'lindex' with multiple index args */
@@ -4579,10 +4984,11 @@ TEBCresume(
 	 * Do the 'lindex' operation.
 	 */
 
+	TRACE(("%d => ", opnd));
 	objResultPtr = TclLindexFlat(interp, OBJ_AT_DEPTH(numIndices),
 		numIndices, &OBJ_AT_DEPTH(numIndices - 1));
 	if (!objResultPtr) {
-	    TRACE_WITH_OBJ(("%d => ERROR: ", opnd), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4590,7 +4996,7 @@ TEBCresume(
 	 * Set result.
 	 */
 
-	TRACE(("%d => %s\n", opnd, O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_V(5, opnd, -1);
 
     case INST_LSET_FLAT:
@@ -4600,6 +5006,7 @@ TEBCresume(
 
 	opnd = TclGetUInt4AtPtr(pc + 1);
 	numIndices = opnd - 2;
+	TRACE(("%d => ", opnd));
 
 	/*
 	 * Get the old value of variable, and remove the stack ref. This is
@@ -4618,7 +5025,7 @@ TEBCresume(
 	objResultPtr = TclLsetFlat(interp, valuePtr, numIndices,
 		&OBJ_AT_DEPTH(numIndices), OBJ_AT_TOS);
 	if (!objResultPtr) {
-	    TRACE_WITH_OBJ(("%d => ERROR: ", opnd), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4626,7 +5033,7 @@ TEBCresume(
 	 * Set result.
 	 */
 
-	TRACE(("%d => %s\n", opnd, O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_V(5, numIndices+1, -1);
 
     case INST_LSET_LIST:	/* 'lset' with 4 args */
@@ -4646,6 +5053,8 @@ TEBCresume(
 
 	valuePtr = OBJ_AT_TOS;
 	value2Ptr = OBJ_UNDER_TOS;
+	TRACE(("\"%.30s\" \"%.30s\" \"%.30s\" => ",
+		O2S(value2Ptr), O2S(valuePtr), O2S(objPtr)));
 
 	/*
 	 * Compute the new variable value.
@@ -4653,8 +5062,7 @@ TEBCresume(
 
 	objResultPtr = TclLsetList(interp, objPtr, value2Ptr, valuePtr);
 	if (!objResultPtr) {
-	    TRACE_WITH_OBJ(("\"%.30s\" => ERROR: ", O2S(value2Ptr)),
-		    Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4662,7 +5070,7 @@ TEBCresume(
 	 * Set result.
 	 */
 
-	TRACE(("=> %s\n", O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 2, -1);
 
     case INST_LIST_RANGE_IMM:	/* lrange with objc==4 and both indices in
@@ -4675,6 +5083,8 @@ TEBCresume(
 	valuePtr = OBJ_AT_TOS;
 	fromIdx = TclGetInt4AtPtr(pc+1);
 	toIdx = TclGetInt4AtPtr(pc+5);
+	TRACE(("\"%.30s\" %d %d => ", O2S(valuePtr), TclGetInt4AtPtr(pc+1),
+		TclGetInt4AtPtr(pc+5)));
 
 	/*
 	 * Get the contents of the list, making sure that it really is a list
@@ -4682,8 +5092,7 @@ TEBCresume(
 	 */
 
 	if (TclListObjGetElements(interp, valuePtr, &objc, &objv) != TCL_OK) {
-	    TRACE_WITH_OBJ(("\"%.30s\" %d %d => ERROR: ", O2S(valuePtr),
-		    fromIdx, toIdx), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4740,8 +5149,6 @@ TEBCresume(
 		List *listPtr = valuePtr->internalRep.twoPtrValue.ptr1;
 
 		if (listPtr->refCount == 1) {
-		    TRACE(("\"%.30s\" %d %d => ", O2S(valuePtr),
-			    TclGetInt4AtPtr(pc+1), TclGetInt4AtPtr(pc+5)));
 		    for (index=toIdx+1; index<objc ; index++) {
 			TclDecrRefCount(objv[index]);
 		    }
@@ -4757,8 +5164,7 @@ TEBCresume(
 	    TclNewObj(objResultPtr);
 	}
 
-	TRACE_WITH_OBJ(("\"%.30s\" %d %d => ", O2S(valuePtr),
-		TclGetInt4AtPtr(pc+1), TclGetInt4AtPtr(pc+5)), objResultPtr);
+	TRACE_APPEND(("\"%.30s\"", O2S(objResultPtr)));
 	NEXT_INST_F(9, 1, 1);
 
     case INST_LIST_IN:
@@ -4767,9 +5173,9 @@ TEBCresume(
 	valuePtr = OBJ_UNDER_TOS;
 
 	s1 = TclGetStringFromObj(valuePtr, &s1len);
+	TRACE(("\"%.30s\" \"%.30s\" => ", O2S(valuePtr), O2S(value2Ptr)));
 	if (TclListObjLength(interp, value2Ptr, &length) != TCL_OK) {
-	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ERROR: ", O2S(valuePtr),
-		    O2S(value2Ptr)), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	match = 0;
@@ -4800,7 +5206,7 @@ TEBCresume(
 	    match = !match;
 	}
 
-	TRACE(("%.20s %.20s => %d\n", O2S(valuePtr), O2S(value2Ptr), match));
+	TRACE_APPEND(("%d\n", match));
 
 	/*
 	 * Peep-hole optimisation: if you're about to jump, do jump from here.
@@ -4808,21 +5214,7 @@ TEBCresume(
 	 * for branching.
 	 */
 
-	pc++;
-#ifndef TCL_COMPILE_DEBUG
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((match ? 2 : TclGetInt1AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((match ? TclGetInt1AtPtr(pc+1) : 2), 2, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((match ? 5 : TclGetInt4AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((match ? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
-	}
-#endif
-	objResultPtr = TCONST(match);
-	NEXT_INST_F(0, 2, 1);
+	JUMP_PEEPHOLE_F(match, 1, 2);
 
     case INST_LIST_CONCAT:
 	value2Ptr = OBJ_AT_TOS;
@@ -4832,7 +5224,7 @@ TEBCresume(
 	    objResultPtr = Tcl_DuplicateObj(valuePtr);
 	    if (Tcl_ListObjAppendList(interp, objResultPtr,
 		    value2Ptr) != TCL_OK) {
-		TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		TclDecrRefCount(objResultPtr);
 		goto gotError;
 	    }
@@ -4840,7 +5232,7 @@ TEBCresume(
 	    NEXT_INST_F(1, 2, 1);
 	} else {
 	    if (Tcl_ListObjAppendList(interp, valuePtr, value2Ptr) != TCL_OK){
-		TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    TRACE_APPEND(("\"%.30s\"\n", O2S(valuePtr)));
@@ -4975,25 +5367,74 @@ TEBCresume(
 		break;
 	    }
 	}
-	if (match < 0) {
-	    TclNewIntObj(objResultPtr, -1);
-	} else {
-	    objResultPtr = TCONST(match > 0);
-	}
-	TRACE(("%.20s %.20s => %s\n", O2S(valuePtr), O2S(value2Ptr),
-		O2S(objResultPtr)));
-	NEXT_INST_F(1, 2, 1);
+
+	TRACE(("\"%.20s\" \"%.20s\" => %d\n", O2S(valuePtr), O2S(value2Ptr),
+		(match < 0 ? -1 : match > 0 ? 1 : 0)));
+	JUMP_PEEPHOLE_F(match, 1, 2);
 
     case INST_STR_LEN:
 	valuePtr = OBJ_AT_TOS;
 	length = Tcl_GetCharLength(valuePtr);
 	TclNewIntObj(objResultPtr, length);
-	TRACE(("%.20s => %d\n", O2S(valuePtr), length));
+	TRACE(("\"%.20s\" => %d\n", O2S(valuePtr), length));
 	NEXT_INST_F(1, 1, 1);
 
+    case INST_STR_UPPER:
+	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
+	if (Tcl_IsShared(valuePtr)) {
+	    s1 = TclGetStringFromObj(valuePtr, &length);
+	    TclNewStringObj(objResultPtr, s1, length);
+	    length = Tcl_UtfToUpper(TclGetString(objResultPtr));
+	    Tcl_SetObjLength(objResultPtr, length);
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(objResultPtr)));
+	    NEXT_INST_F(1, 1, 1);
+	} else {
+	    length = Tcl_UtfToUpper(TclGetString(valuePtr));
+	    Tcl_SetObjLength(valuePtr, length);
+	    TclFreeIntRep(valuePtr);
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(valuePtr)));
+	    NEXT_INST_F(1, 0, 0);
+	}
+    case INST_STR_LOWER:
+	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
+	if (Tcl_IsShared(valuePtr)) {
+	    s1 = TclGetStringFromObj(valuePtr, &length);
+	    TclNewStringObj(objResultPtr, s1, length);
+	    length = Tcl_UtfToLower(TclGetString(objResultPtr));
+	    Tcl_SetObjLength(objResultPtr, length);
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(objResultPtr)));
+	    NEXT_INST_F(1, 1, 1);
+	} else {
+	    length = Tcl_UtfToLower(TclGetString(valuePtr));
+	    Tcl_SetObjLength(valuePtr, length);
+	    TclFreeIntRep(valuePtr);
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(valuePtr)));
+	    NEXT_INST_F(1, 0, 0);
+	}
+    case INST_STR_TITLE:
+	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
+	if (Tcl_IsShared(valuePtr)) {
+	    s1 = TclGetStringFromObj(valuePtr, &length);
+	    TclNewStringObj(objResultPtr, s1, length);
+	    length = Tcl_UtfToTitle(TclGetString(objResultPtr));
+	    Tcl_SetObjLength(objResultPtr, length);
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(objResultPtr)));
+	    NEXT_INST_F(1, 1, 1);
+	} else {
+	    length = Tcl_UtfToTitle(TclGetString(valuePtr));
+	    Tcl_SetObjLength(valuePtr, length);
+	    TclFreeIntRep(valuePtr);
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(valuePtr)));
+	    NEXT_INST_F(1, 0, 0);
+	}
+
     case INST_STR_INDEX:
 	value2Ptr = OBJ_AT_TOS;
 	valuePtr = OBJ_UNDER_TOS;
+	TRACE(("\"%.20s\" %.20s => ", O2S(valuePtr), O2S(value2Ptr)));
 
 	/*
 	 * Get char length to calulate what 'end' means.
@@ -5001,6 +5442,7 @@ TEBCresume(
 
 	length = Tcl_GetCharLength(valuePtr);
 	if (TclGetIntForIndexM(interp, value2Ptr, length-1, &index)!=TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -5026,18 +5468,18 @@ TEBCresume(
 	    objResultPtr = Tcl_NewStringObj(buf, length);
 	}
 
-	TRACE(("%.20s %.20s => %s\n", O2S(valuePtr), O2S(value2Ptr),
-		O2S(objResultPtr)));
+	TRACE_APPEND(("\"%s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 2, 1);
 
     case INST_STR_RANGE:
-	TRACE(("\"%.20s\" %s %s =>",
+	TRACE(("\"%.20s\" %.20s %.20s =>",
 		O2S(OBJ_AT_DEPTH(2)), O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS)));
 	length = Tcl_GetCharLength(OBJ_AT_DEPTH(2)) - 1;
 	if (TclGetIntForIndexM(interp, OBJ_UNDER_TOS, length,
 		    &fromIdx) != TCL_OK
 	    || TclGetIntForIndexM(interp, OBJ_AT_TOS, length,
 		    &toIdx) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -5097,33 +5539,206 @@ TEBCresume(
 	int length3;
 	Tcl_Obj *value3Ptr;
 
+    case INST_STR_REPLACE:
+	value3Ptr = POP_OBJECT();
+	valuePtr = OBJ_AT_DEPTH(2);
+	length = Tcl_GetCharLength(valuePtr) - 1;
+	TRACE(("\"%.20s\" %s %s \"%.20s\" => ", O2S(valuePtr),
+		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), O2S(value3Ptr)));
+	if (TclGetIntForIndexM(interp, OBJ_UNDER_TOS, length,
+		    &fromIdx) != TCL_OK
+	    || TclGetIntForIndexM(interp, OBJ_AT_TOS, length,
+		    &toIdx) != TCL_OK) {
+	    TclDecrRefCount(value3Ptr);
+	    TRACE_ERROR(interp);
+	    goto gotError;
+	}
+	TclDecrRefCount(OBJ_AT_TOS);
+	(void) POP_OBJECT();
+	TclDecrRefCount(OBJ_AT_TOS);
+	(void) POP_OBJECT();
+	if (fromIdx < 0) {
+	    fromIdx = 0;
+	}
+
+	if (fromIdx > toIdx || fromIdx > length) {
+	    TRACE_APPEND(("\"%.30s\"\n", O2S(valuePtr)));
+	    TclDecrRefCount(value3Ptr);
+	    NEXT_INST_F(1, 0, 0);
+	}
+
+	if (toIdx > length) {
+	    toIdx = length;
+	}
+
+	if (fromIdx == 0 && toIdx == length) {
+	    TclDecrRefCount(OBJ_AT_TOS);
+	    OBJ_AT_TOS = value3Ptr;
+	    TRACE_APPEND(("\"%.30s\"\n", O2S(value3Ptr)));
+	    NEXT_INST_F(1, 0, 0);
+	}
+
+	length3 = Tcl_GetCharLength(value3Ptr);
+
+	/*
+	 * Remove substring. In-place.
+	 */
+
+	if (length3 == 0 && !Tcl_IsShared(valuePtr) && toIdx == length) {
+	    TclDecrRefCount(value3Ptr);
+	    Tcl_SetObjLength(valuePtr, fromIdx);
+	    TRACE_APPEND(("\"%.30s\"\n", O2S(valuePtr)));
+	    NEXT_INST_F(1, 0, 0);
+	}
+
+	/*
+	 * See if we can splice in place. This happens when the number of
+	 * characters being replaced is the same as the number of characters
+	 * in the string to be inserted.
+	 */
+
+	if (length3 - 1 == toIdx - fromIdx) {
+	    unsigned char *bytes1, *bytes2;
+
+	    if (Tcl_IsShared(valuePtr)) {
+		objResultPtr = Tcl_DuplicateObj(valuePtr);
+		if (TclIsPureByteArray(objResultPtr)
+			&& TclIsPureByteArray(value3Ptr)) {
+		    bytes1 = Tcl_GetByteArrayFromObj(objResultPtr, NULL);
+		    bytes2 = Tcl_GetByteArrayFromObj(value3Ptr, NULL);
+		    memcpy(bytes1 + fromIdx, bytes2, length3);
+		} else {
+		    ustring1 = Tcl_GetUnicodeFromObj(objResultPtr, NULL);
+		    ustring2 = Tcl_GetUnicodeFromObj(value3Ptr, NULL);
+		    memcpy(ustring1 + fromIdx, ustring2,
+			    length3 * sizeof(Tcl_UniChar));
+
+		    /*
+		     * Magic! Flush the info in the string internal rep that
+		     * refers to the about-to-be-invalidated UTF-8 rep. This
+		     * sets the 'allocated' field of the String structure to 0
+		     * to indicate that a new buffer needs to be allocated.
+		     * This is safe; we know we've got a tclStringTypePtr set
+		     * at this point (post Tcl_GetUnicodeFromObj).
+		     */
+
+		    ((int *) objResultPtr->internalRep.otherValuePtr)[1] = 0;
+		}
+		Tcl_InvalidateStringRep(objResultPtr);
+		TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
+		NEXT_INST_F(1, 1, 1);
+	    } else {
+		if (TclIsPureByteArray(valuePtr)
+			&& TclIsPureByteArray(value3Ptr)) {
+		    bytes1 = Tcl_GetByteArrayFromObj(valuePtr, NULL);
+		    bytes2 = Tcl_GetByteArrayFromObj(value3Ptr, NULL);
+		    memcpy(bytes1 + fromIdx, bytes2, length3);
+		} else {
+		    ustring1 = Tcl_GetUnicodeFromObj(valuePtr, NULL);
+		    ustring2 = Tcl_GetUnicodeFromObj(value3Ptr, NULL);
+		    memcpy(ustring1 + fromIdx, ustring2,
+			    length3 * sizeof(Tcl_UniChar));
+
+		    /*
+		     * Magic! Flush the info in the string internal rep that
+		     * refers to the about-to-be-invalidated UTF-8 rep. This
+		     * sets the 'allocated' field of the String structure to 0
+		     * to indicate that a new buffer needs to be allocated.
+		     * This is safe; we know we've got a tclStringTypePtr set
+		     * at this point (post Tcl_GetUnicodeFromObj).
+		     */
+
+		    ((int *) objResultPtr->internalRep.otherValuePtr)[1] = 0;
+		}
+		Tcl_InvalidateStringRep(valuePtr);
+		TRACE_APPEND(("\"%.30s\"\n", O2S(valuePtr)));
+		NEXT_INST_F(1, 0, 0);
+	    }
+	}
+
+	/*
+	 * Get the unicode representation; this is where we guarantee to lose
+	 * bytearrays.
+	 */
+
+	ustring1 = Tcl_GetUnicodeFromObj(valuePtr, &length);
+	length--;
+
+	/*
+	 * Remove substring using copying.
+	 */
+
+	if (length3 == 0) {
+	    if (fromIdx > 0) {
+		objResultPtr = Tcl_NewUnicodeObj(ustring1, fromIdx);
+		if (toIdx < length) {
+		    Tcl_AppendUnicodeToObj(objResultPtr, ustring1 + toIdx + 1,
+			    length - toIdx);
+		}
+	    } else {
+		objResultPtr = Tcl_NewUnicodeObj(ustring1 + toIdx + 1,
+			length - toIdx);
+	    }
+	    TclDecrRefCount(value3Ptr);
+	    TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
+	    NEXT_INST_F(1, 1, 1);
+	}
+
+	/*
+	 * Splice string pieces by full copying.
+	 */
+
+	if (fromIdx > 0) {
+	    objResultPtr = Tcl_NewUnicodeObj(ustring1, fromIdx);
+	    Tcl_AppendObjToObj(objResultPtr, value3Ptr);
+	    if (toIdx < length) {
+		Tcl_AppendUnicodeToObj(objResultPtr, ustring1 + toIdx + 1,
+			length - toIdx);
+	    }
+	} else if (Tcl_IsShared(value3Ptr)) {
+	    objResultPtr = Tcl_DuplicateObj(value3Ptr);
+	    if (toIdx < length) {
+		Tcl_AppendUnicodeToObj(objResultPtr, ustring1 + toIdx + 1,
+			length - toIdx);
+	    }
+	} else {
+	    objResultPtr = value3Ptr;
+	    if (toIdx < length) {
+		Tcl_AppendUnicodeToObj(objResultPtr, ustring1 + toIdx + 1,
+			length - toIdx);
+	    }
+	}
+	TclDecrRefCount(value3Ptr);
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
+	NEXT_INST_F(1, 1, 1);
+
     case INST_STR_MAP:
 	valuePtr = OBJ_AT_TOS;		/* "Main" string. */
 	value3Ptr = OBJ_UNDER_TOS;	/* "Target" string. */
 	value2Ptr = OBJ_AT_DEPTH(2);	/* "Source" string. */
 	if (value3Ptr == value2Ptr) {
 	    objResultPtr = valuePtr;
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	} else if (valuePtr == value2Ptr) {
 	    objResultPtr = value3Ptr;
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	}
 	ustring1 = Tcl_GetUnicodeFromObj(valuePtr, &length);
 	if (length == 0) {
 	    objResultPtr = valuePtr;
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	}
 	ustring2 = Tcl_GetUnicodeFromObj(value2Ptr, &length2);
 	if (length2 > length || length2 == 0) {
 	    objResultPtr = valuePtr;
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	} else if (length2 == length) {
 	    if (memcmp(ustring1, ustring2, sizeof(Tcl_UniChar) * length)) {
 		objResultPtr = valuePtr;
 	    } else {
 		objResultPtr = value3Ptr;
 	    }
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	}
 	ustring3 = Tcl_GetUnicodeFromObj(value3Ptr, &length3);
 
@@ -5152,6 +5767,7 @@ TEBCresume(
 
 	    Tcl_AppendUnicodeToObj(objResultPtr, p, ustring1 - p);
 	}
+    doneStringMap:
 	TRACE_WITH_OBJ(("%.20s %.20s %.20s => ",
 		O2S(value2Ptr), O2S(value3Ptr), O2S(valuePtr)), objResultPtr);
 	NEXT_INST_V(1, 3, 1);
@@ -5174,7 +5790,6 @@ TEBCresume(
 
 	TRACE(("%.20s %.20s => %d\n",
 		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), match));
-
 	TclNewIntObj(objResultPtr, match);
 	NEXT_INST_F(1, 2, 1);
 
@@ -5198,6 +5813,25 @@ TEBCresume(
 
 	TclNewIntObj(objResultPtr, match);
 	NEXT_INST_F(1, 2, 1);
+
+    case INST_STR_CLASS:
+	opnd = TclGetInt1AtPtr(pc+1);
+	valuePtr = OBJ_AT_TOS;
+	TRACE(("%s \"%.30s\" => ", tclStringClassTable[opnd].name,
+		O2S(valuePtr)));
+	ustring1 = Tcl_GetUnicodeFromObj(valuePtr, &length);
+	match = 1;
+	if (length > 0) {
+	    end = ustring1 + length;
+	    for (p=ustring1 ; p<end ; p++) {
+		if (!tclStringClassTable[opnd].comparator(*p)) {
+		    match = 0;
+		    break;
+		}
+	    }
+	}
+	TRACE_APPEND(("%d\n", match));
+	JUMP_PEEPHOLE_F(match, 2, 1);
     }
 
     case INST_STR_MATCH:
@@ -5240,26 +5874,77 @@ TEBCresume(
 	 * Peep-hole optimisation: if you're about to jump, do jump from here.
 	 */
 
-	pc += 2;
-#ifndef TCL_COMPILE_DEBUG
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((match? 2 : TclGetInt1AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((match? TclGetInt1AtPtr(pc+1) : 2), 2, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((match? 5 : TclGetInt4AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((match? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
+	JUMP_PEEPHOLE_F(match, 2, 2);
+
+    {
+	const char *string1, *string2;
+	int trim1, trim2;
+
+    case INST_STR_TRIM_LEFT:
+	valuePtr = OBJ_UNDER_TOS;	/* String */
+	value2Ptr = OBJ_AT_TOS;		/* TrimSet */
+	string2 = TclGetStringFromObj(value2Ptr, &length2);
+	string1 = TclGetStringFromObj(valuePtr, &length);
+	trim1 = TclTrimLeft(string1, length, string2, length2);
+	trim2 = 0;
+	goto createTrimmedString;
+    case INST_STR_TRIM_RIGHT:
+	valuePtr = OBJ_UNDER_TOS;	/* String */
+	value2Ptr = OBJ_AT_TOS;		/* TrimSet */
+	string2 = TclGetStringFromObj(value2Ptr, &length2);
+	string1 = TclGetStringFromObj(valuePtr, &length);
+	trim2 = TclTrimRight(string1, length, string2, length2);
+	trim1 = 0;
+	goto createTrimmedString;
+    case INST_STR_TRIM:
+	valuePtr = OBJ_UNDER_TOS;	/* String */
+	value2Ptr = OBJ_AT_TOS;		/* TrimSet */
+	string2 = TclGetStringFromObj(value2Ptr, &length2);
+	string1 = TclGetStringFromObj(valuePtr, &length);
+	trim1 = TclTrimLeft(string1, length, string2, length2);
+	if (trim1 < length) {
+	    trim2 = TclTrimRight(string1, length, string2, length2);
+	} else {
+	    trim2 = 0;
+	}
+    createTrimmedString:
+	/*
+	 * Careful here; trim set often contains non-ASCII characters so we
+	 * take care when printing. [Bug 971cb4f1db]
+	 */
+
+#ifdef TCL_COMPILE_DEBUG
+	if (traceInstructions) {
+	    TRACE(("\"%.30s\" ", O2S(valuePtr)));
+	    TclPrintObject(stdout, value2Ptr, 30);
+	    printf(" => ");
 	}
 #endif
-	objResultPtr = TCONST(match);
-	NEXT_INST_F(0, 2, 1);
+	if (trim1 == 0 && trim2 == 0) {
+#ifdef TCL_COMPILE_DEBUG
+	    if (traceInstructions) {
+		TclPrintObject(stdout, valuePtr, 30);
+		printf("\n");
+	    }
+#endif
+	    NEXT_INST_F(1, 1, 0);
+	} else {
+	    objResultPtr = Tcl_NewStringObj(string1+trim1, length-trim1-trim2);
+#ifdef TCL_COMPILE_DEBUG
+	    if (traceInstructions) {
+		TclPrintObject(stdout, objResultPtr, 30);
+		printf("\n");
+	    }
+#endif
+	    NEXT_INST_F(1, 2, 1);
+	}
+    }
 
     case INST_REGEXP:
 	cflags = TclGetInt1AtPtr(pc+1); /* RE compile flages like NOCASE */
 	valuePtr = OBJ_AT_TOS;		/* String */
 	value2Ptr = OBJ_UNDER_TOS;	/* Pattern */
+	TRACE(("\"%.30s\" \"%.30s\" => ", O2S(valuePtr), O2S(value2Ptr)));
 
 	/*
 	 * Compile and match the regular expression.
@@ -5270,44 +5955,24 @@ TEBCresume(
 		    Tcl_GetRegExpFromObj(interp, value2Ptr, cflags);
 
 	    if (regExpr == NULL) {
-		goto regexpFailure;
+		TRACE_ERROR(interp);
+		goto gotError;
 	    }
-
 	    match = Tcl_RegExpExecObj(interp, regExpr, valuePtr, 0, 0, 0);
-
 	    if (match < 0) {
-	    regexpFailure:
-#ifdef TCL_COMPILE_DEBUG
-		objResultPtr = Tcl_GetObjResult(interp);
-		TRACE_WITH_OBJ(("%.20s %.20s => ERROR: ",
-			O2S(valuePtr), O2S(value2Ptr)), objResultPtr);
-#endif
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
 
-	TRACE(("%.20s %.20s => %d\n", O2S(valuePtr), O2S(value2Ptr), match));
+	TRACE_APPEND(("%d\n", match));
 
 	/*
 	 * Peep-hole optimisation: if you're about to jump, do jump from here.
 	 * Adjustment is 2 due to the nocase byte.
 	 */
 
-	pc += 2;
-#ifndef TCL_COMPILE_DEBUG
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((match? 2 : TclGetInt1AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((match? TclGetInt1AtPtr(pc+1) : 2), 2, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((match? 5 : TclGetInt4AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((match? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
-	}
-#endif
-	objResultPtr = TCONST(match);
-	NEXT_INST_F(0, 2, 1);
+	JUMP_PEEPHOLE_F(match, 2, 2);
     }
 
     /*
@@ -5321,6 +5986,14 @@ TEBCresume(
 	int type1, type2;
 	long l1, l2, lResult;
 
+    case INST_NUM_TYPE:
+	if (GetNumberFromObj(NULL, OBJ_AT_TOS, &ptr1, &type1) != TCL_OK) {
+	    type1 = 0;
+	}
+	TclNewIntObj(objResultPtr, type1);
+	TRACE(("\"%.20s\" => %d\n", O2S(OBJ_AT_TOS), type1));
+	NEXT_INST_F(1, 1, 1);
+
     case INST_EQ:
     case INST_NEQ:
     case INST_LT:
@@ -5405,21 +6078,9 @@ TEBCresume(
 	 */
 
     foundResult:
-	pc++;
-#ifndef TCL_COMPILE_DEBUG
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((iResult? 2 : TclGetInt1AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((iResult? TclGetInt1AtPtr(pc+1) : 2), 2, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((iResult? 5 : TclGetInt4AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((iResult? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
-	}
-#endif
-	objResultPtr = TCONST(iResult);
-	NEXT_INST_F(0, 2, 1);
+	TRACE(("\"%.20s\" \"%.20s\" => %d\n", O2S(valuePtr), O2S(value2Ptr),
+		iResult));
+	JUMP_PEEPHOLE_F(iResult, 1, 2);
     }
 
     case INST_MOD:
@@ -5506,13 +6167,13 @@ TEBCresume(
 		if (l2 < 0) {
 		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			    "negative shift argument", -1));
-#if 0
+#ifdef ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 			    "domain error: argument not in valid range",
 			    NULL);
 		    CACHE_STACK_INFO();
-#endif
+#endif /* ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR */
 		    goto gotError;
 		} else if (l1 == 0) {
 		    TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr)));
@@ -5554,13 +6215,13 @@ TEBCresume(
 		if (l2 < 0) {
 		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			    "negative shift argument", -1));
-#if 0
+#ifdef ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 			    "domain error: argument not in valid range",
 			    NULL);
 		    CACHE_STACK_INFO();
-#endif
+#endif /* ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR */
 		    goto gotError;
 		} else if (l1 == 0) {
 		    TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr)));
@@ -5577,12 +6238,12 @@ TEBCresume(
 
 		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			    "integer value too large to represent", -1));
-#if 0
+#ifdef ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "IOVERFLOW",
 			    "integer value too large to represent", NULL);
 		    CACHE_STACK_INFO();
-#endif
+#endif /* ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR */
 		    goto gotError;
 		} else {
 		    int shift = (int) l2;
@@ -5640,8 +6301,7 @@ TEBCresume(
 	    TRACE_APPEND(("DIVIDE BY ZERO\n"));
 	    goto divideByZero;
 	} else if (objResultPtr == GENERAL_ARITHMETIC_ERROR) {
-	    TRACE_APPEND(("ERROR: %s\n",
-		    TclGetString(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	} else if (objResultPtr == NULL) {
 	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
@@ -5813,8 +6473,7 @@ TEBCresume(
 	    TRACE_APPEND(("EXPONENT OF ZERO\n"));
 	    goto exponOfZero;
 	} else if (objResultPtr == GENERAL_ARITHMETIC_ERROR) {
-	    TRACE_APPEND(("ERROR: %s\n",
-		    TclGetString(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	} else if (objResultPtr == NULL) {
 	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
@@ -5832,7 +6491,7 @@ TEBCresume(
 	/* TODO - check claim that taking address of b harms performance */
 	/* TODO - consider optimization search for constants */
 	if (TclGetBooleanFromObj(NULL, valuePtr, &b) != TCL_OK) {
-	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s\n", O2S(valuePtr),
+	    TRACE(("\"%.20s\" => ERROR: illegal type %s\n", O2S(valuePtr),
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    DECACHE_STACK_INFO();
 	    IllegalExprOperandType(interp, pc, valuePtr);
@@ -5841,18 +6500,20 @@ TEBCresume(
 	}
 	/* TODO: Consider peephole opt. */
 	objResultPtr = TCONST(!b);
+	TRACE_WITH_OBJ(("%s => ", O2S(valuePtr)), objResultPtr);
 	NEXT_INST_F(1, 1, 1);
     }
 
     case INST_BITNOT:
 	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 	if ((GetNumberFromObj(NULL, valuePtr, &ptr1, &type1) != TCL_OK)
 		|| (type1==TCL_NUMBER_NAN) || (type1==TCL_NUMBER_DOUBLE)) {
 	    /*
 	     * ... ~$NonInteger => raise an error.
 	     */
 
-	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
+	    TRACE_APPEND(("ERROR: illegal type %s\n",
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    DECACHE_STACK_INFO();
 	    IllegalExprOperandType(interp, pc, valuePtr);
@@ -5863,23 +6524,28 @@ TEBCresume(
 	    l1 = *((const long *) ptr1);
 	    if (Tcl_IsShared(valuePtr)) {
 		TclNewLongObj(objResultPtr, ~l1);
+		TRACE_APPEND(("%s\n", O2S(objResultPtr)));
 		NEXT_INST_F(1, 1, 1);
 	    }
 	    TclSetLongObj(valuePtr, ~l1);
+	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 	objResultPtr = ExecuteExtendedUnaryMathOp(*pc, valuePtr);
 	if (objResultPtr != NULL) {
+	    TRACE_APPEND(("%s\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 1, 1);
 	} else {
+	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 
     case INST_UMINUS:
 	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 	if ((GetNumberFromObj(NULL, valuePtr, &ptr1, &type1) != TCL_OK)
 		|| IsErroringNaNType(type1)) {
-	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
+	    TRACE_APPEND(("ERROR: illegal type %s \n",
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    DECACHE_STACK_INFO();
 	    IllegalExprOperandType(interp, pc, valuePtr);
@@ -5889,23 +6555,28 @@ TEBCresume(
 	switch (type1) {
 	case TCL_NUMBER_NAN:
 	    /* -NaN => NaN */
+	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	case TCL_NUMBER_LONG:
 	    l1 = *((const long *) ptr1);
 	    if (l1 != LONG_MIN) {
 		if (Tcl_IsShared(valuePtr)) {
 		    TclNewLongObj(objResultPtr, -l1);
+		    TRACE_APPEND(("%s\n", O2S(objResultPtr)));
 		    NEXT_INST_F(1, 1, 1);
 		}
 		TclSetLongObj(valuePtr, -l1);
+		TRACE_APPEND(("%s\n", O2S(valuePtr)));
 		NEXT_INST_F(1, 0, 0);
 	    }
 	    /* FALLTHROUGH */
 	}
 	objResultPtr = ExecuteExtendedUnaryMathOp(*pc, valuePtr);
 	if (objResultPtr != NULL) {
+	    TRACE_APPEND(("%s\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 1, 1);
 	} else {
+	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 
@@ -5918,6 +6589,7 @@ TEBCresume(
 	 */
 
 	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 
 	if (GetNumberFromObj(NULL, valuePtr, &ptr1, &type1) != TCL_OK) {
 	    if (*pc == INST_UPLUS) {
@@ -5925,7 +6597,7 @@ TEBCresume(
 		 * ... +$NonNumeric => raise an error.
 		 */
 
-		TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
+		TRACE_APPEND(("ERROR: illegal type %s\n",
 			(valuePtr->typePtr? valuePtr->typePtr->name:"null")));
 		DECACHE_STACK_INFO();
 		IllegalExprOperandType(interp, pc, valuePtr);
@@ -5934,7 +6606,7 @@ TEBCresume(
 	    }
 
 	    /* ... TryConvertToNumeric($NonNumeric) is acceptable */
-	    TRACE(("\"%.20s\" => not numeric\n", O2S(valuePtr)));
+	    TRACE_APPEND(("not numeric\n"));
 	    NEXT_INST_F(1, 0, 0);
 	}
 	if (IsErroringNaNType(type1)) {
@@ -5943,7 +6615,7 @@ TEBCresume(
 		 * ... +$NonNumeric => raise an error.
 		 */
 
-		TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
+		TRACE_APPEND(("ERROR: illegal type %s\n",
 			(valuePtr->typePtr? valuePtr->typePtr->name:"null")));
 		DECACHE_STACK_INFO();
 		IllegalExprOperandType(interp, pc, valuePtr);
@@ -5953,8 +6625,7 @@ TEBCresume(
 		 * Numeric conversion of NaN -> error.
 		 */
 
-		TRACE(("\"%.20s\" => IEEE FLOATING PT ERROR\n",
-			O2S(objResultPtr)));
+		TRACE_APPEND(("ERROR: IEEE floating pt error\n"));
 		DECACHE_STACK_INFO();
 		TclExprFloatError(interp, *((const double *) ptr1));
 		CACHE_STACK_INFO();
@@ -5972,7 +6643,7 @@ TEBCresume(
 	 */
 
 	if (valuePtr->bytes == NULL) {
-	    TRACE(("\"%.20s\" => numeric, same Tcl_Obj\n", O2S(valuePtr)));
+	    TRACE_APPEND(("numeric, same Tcl_Obj\n"));
 	    NEXT_INST_F(1, 0, 0);
 	}
 	if (Tcl_IsShared(valuePtr)) {
@@ -5987,11 +6658,11 @@ TEBCresume(
 	    valuePtr->bytes = NULL;
 	    objResultPtr = Tcl_DuplicateObj(valuePtr);
 	    valuePtr->bytes = savedString;
-	    TRACE(("\"%.20s\" => numeric, new Tcl_Obj\n", O2S(valuePtr)));
+	    TRACE_APPEND(("numeric, new Tcl_Obj\n"));
 	    NEXT_INST_F(1, 1, 1);
 	}
 	TclInvalidateStringRep(valuePtr);
-	TRACE(("\"%.20s\" => numeric, same Tcl_Obj\n", O2S(valuePtr)));
+	TRACE_APPEND(("numeric, same Tcl_Obj\n"));
 	NEXT_INST_F(1, 0, 0);
     }
 
@@ -6000,6 +6671,17 @@ TEBCresume(
      * -----------------------------------------------------------------
      */
 
+    case INST_TRY_CVT_TO_BOOLEAN:
+	valuePtr = OBJ_AT_TOS;
+	if (valuePtr->typePtr == &tclBooleanType) {
+	    objResultPtr = TCONST(1);
+	} else {
+	    int result = (TclSetBooleanFromAny(NULL, valuePtr) == TCL_OK);
+	    objResultPtr = TCONST(result);
+	}
+	TRACE_WITH_OBJ(("\"%.30s\" => ", O2S(valuePtr)), objResultPtr);
+	NEXT_INST_F(1, 0, 1);
+
     case INST_BREAK:
 	/*
 	DECACHE_STACK_INFO();
@@ -6008,6 +6690,7 @@ TEBCresume(
 	*/
 	result = TCL_BREAK;
 	cleanup = 0;
+	TRACE(("=> BREAK!\n"));
 	goto processExceptionReturn;
 
     case INST_CONTINUE:
@@ -6018,6 +6701,7 @@ TEBCresume(
 	*/
 	result = TCL_CONTINUE;
 	cleanup = 0;
+	TRACE(("=> CONTINUE!\n"));
 	goto processExceptionReturn;
 
     {
@@ -6029,7 +6713,7 @@ TEBCresume(
 	int varIndex, valIndex, continueLoop, j, iterTmpIndex;
 	long i;
 
-    case INST_FOREACH_START4:
+    case INST_FOREACH_START4: /* DEPRECATED */
 	/*
 	 * Initialize the temporary local var that holds the count of the
 	 * number of iterations of the loop body to -1.
@@ -6062,13 +6746,14 @@ TEBCresume(
 	NEXT_INST_F(5, 0, 0);
 #endif
 
-    case INST_FOREACH_STEP4:
+    case INST_FOREACH_STEP4: /* DEPRECATED */
 	/*
 	 * "Step" a foreach loop (i.e., begin its next iteration) by assigning
 	 * the next value list element to each loop var.
 	 */
 
 	opnd = TclGetUInt4AtPtr(pc+1);
+	TRACE(("%u => ", opnd));
 	infoPtr = codePtr->auxDataArrayPtr[opnd].clientData;
 	numLists = infoPtr->numLists;
 
@@ -6095,8 +6780,8 @@ TEBCresume(
 	    listVarPtr = LOCAL(listTmpIndex);
 	    listPtr = listVarPtr->value.objPtr;
 	    if (TclListObjLength(interp, listPtr, &listLen) != TCL_OK) {
-		TRACE_WITH_OBJ(("%u => ERROR converting list %ld, \"%s\": ",
-			opnd, i, O2S(listPtr)), Tcl_GetObjResult(interp));
+		TRACE_APPEND(("ERROR converting list %ld, \"%.30s\": %s\n",
+			i, O2S(listPtr), O2S(Tcl_GetObjResult(interp))));
 		goto gotError;
 	    }
 	    if (listLen > iterNum * numVars) {
@@ -6151,9 +6836,9 @@ TEBCresume(
 			if (TclPtrSetVar(interp, varPtr, NULL, NULL, NULL,
 				valuePtr, TCL_LEAVE_ERR_MSG, varIndex)==NULL){
 			    CACHE_STACK_INFO();
-			    TRACE_WITH_OBJ((
-				    "%u => ERROR init. index temp %d: ",
-				    opnd,varIndex), Tcl_GetObjResult(interp));
+			    TRACE_APPEND((
+				    "ERROR init. index temp %d: %s\n",
+				    varIndex, O2S(Tcl_GetObjResult(interp))));
 			    TclDecrRefCount(listPtr);
 			    goto gotError;
 			}
@@ -6165,8 +6850,8 @@ TEBCresume(
 		listTmpIndex++;
 	    }
 	}
-	TRACE(("%u => %d lists, iter %d, %s loop\n", opnd, numLists,
-		iterNum, (continueLoop? "continue" : "exit")));
+	TRACE_APPEND(("%d lists, iter %d, %s loop\n",
+		numLists, iterNum, (continueLoop? "continue" : "exit")));
 
 	/*
 	 * Run-time peep-hole optimisation: the compiler ALWAYS follows
@@ -6180,6 +6865,200 @@ TEBCresume(
 	} else {
 	    NEXT_INST_F((continueLoop? 5 : TclGetInt4AtPtr(pc+1)), 0, 0);
 	}
+
+    }
+    {
+	ForeachInfo *infoPtr;
+	Tcl_Obj *listPtr, **elements, *tmpPtr;
+	ForeachVarList *varListPtr;
+	int numLists, iterMax, listLen, numVars;
+	int iterTmp, iterNum, listTmpDepth;
+	int varIndex, valIndex, j;
+	long i;
+
+    case INST_FOREACH_START:
+	/*
+	 * Initialize the data for the looping construct, pushing the
+	 * corresponding Tcl_Objs to the stack.
+	 */
+
+	opnd = TclGetUInt4AtPtr(pc+1);
+	infoPtr = codePtr->auxDataArrayPtr[opnd].clientData;
+	numLists = infoPtr->numLists;
+	TRACE(("%u => ", opnd));
+
+	/*
+	 * Compute the number of iterations that will be run: iterMax
+	 */
+
+	iterMax = 0;
+	listTmpDepth = numLists-1;
+	for (i = 0;  i < numLists;  i++) {
+	    varListPtr = infoPtr->varLists[i];
+	    numVars = varListPtr->numVars;
+	    listPtr = OBJ_AT_DEPTH(listTmpDepth);
+	    if (TclListObjLength(interp, listPtr, &listLen) != TCL_OK) {
+		TRACE_APPEND(("ERROR converting list %ld, \"%s\": %s",
+			i, O2S(listPtr), O2S(Tcl_GetObjResult(interp))));
+		goto gotError;
+	    }
+	    if (Tcl_IsShared(listPtr)) {
+		objPtr = TclListObjCopy(NULL, listPtr);
+		Tcl_IncrRefCount(objPtr);
+		Tcl_DecrRefCount(listPtr);
+		OBJ_AT_DEPTH(listTmpDepth) = objPtr;
+	    }
+	    iterTmp = (listLen + (numVars - 1))/numVars;
+	    if (iterTmp > iterMax) {
+		iterMax = iterTmp;
+	    }
+	    listTmpDepth--;
+	}
+
+	/*
+	 * Store the iterNum and iterMax in a single Tcl_Obj; we keep a
+	 * nul-string obj with the pointer stored in the ptrValue so that the
+	 * thing is properly garbage collected. THIS OBJ MAKES NO SENSE, but
+	 * it will never leave this scope and is read-only.
+	 */
+
+	TclNewObj(tmpPtr);
+	tmpPtr->internalRep.twoPtrValue.ptr1 = INT2PTR(0);
+	tmpPtr->internalRep.twoPtrValue.ptr2 = INT2PTR(iterMax);
+	PUSH_OBJECT(tmpPtr); /* iterCounts object */
+
+	/*
+	 * Store a pointer to the ForeachInfo struct; same dirty trick
+	 * as above
+	 */
+
+	TclNewObj(tmpPtr);
+	tmpPtr->internalRep.otherValuePtr = infoPtr;
+	PUSH_OBJECT(tmpPtr); /* infoPtr object */
+	TRACE_APPEND(("jump to loop step\n"));
+
+	/*
+	 * Jump directly to the INST_FOREACH_STEP instruction; the C code just
+	 * falls through.
+	 */
+
+	pc += 5 - infoPtr->loopCtTemp;
+
+    case INST_FOREACH_STEP:
+	/*
+	 * "Step" a foreach loop (i.e., begin its next iteration) by assigning
+	 * the next value list element to each loop var.
+	 */
+
+	tmpPtr = OBJ_AT_TOS;
+	infoPtr = tmpPtr->internalRep.otherValuePtr;
+	numLists = infoPtr->numLists;
+	TRACE(("=> "));
+
+	tmpPtr = OBJ_AT_DEPTH(1);
+	iterNum = PTR2INT(tmpPtr->internalRep.twoPtrValue.ptr1);
+	iterMax = PTR2INT(tmpPtr->internalRep.twoPtrValue.ptr2);
+
+	/*
+	 * If some list still has a remaining list element iterate one more
+	 * time. Assign to var the next element from its value list.
+	 */
+
+	if (iterNum < iterMax) {
+	    /*
+	     * Set the variables and jump back to run the body
+	     */
+
+	    tmpPtr->internalRep.twoPtrValue.ptr1 = INT2PTR(iterNum + 1);
+
+	    listTmpDepth = numLists + 1;
+
+	    for (i = 0;  i < numLists;  i++) {
+		varListPtr = infoPtr->varLists[i];
+		numVars = varListPtr->numVars;
+
+		listPtr = OBJ_AT_DEPTH(listTmpDepth);
+		TclListObjGetElements(interp, listPtr, &listLen, &elements);
+
+		valIndex = (iterNum * numVars);
+		for (j = 0;  j < numVars;  j++) {
+		    if (valIndex >= listLen) {
+			TclNewObj(valuePtr);
+		    } else {
+			valuePtr = elements[valIndex];
+		    }
+
+		    varIndex = varListPtr->varIndexes[j];
+		    varPtr = LOCAL(varIndex);
+		    while (TclIsVarLink(varPtr)) {
+			varPtr = varPtr->value.linkPtr;
+		    }
+		    if (TclIsVarDirectWritable(varPtr)) {
+			value2Ptr = varPtr->value.objPtr;
+			if (valuePtr != value2Ptr) {
+			    if (value2Ptr != NULL) {
+				TclDecrRefCount(value2Ptr);
+			    }
+			    varPtr->value.objPtr = valuePtr;
+			    Tcl_IncrRefCount(valuePtr);
+			}
+		    } else {
+			DECACHE_STACK_INFO();
+			if (TclPtrSetVar(interp, varPtr, NULL, NULL, NULL,
+				valuePtr, TCL_LEAVE_ERR_MSG, varIndex)==NULL){
+			    CACHE_STACK_INFO();
+			    TRACE_APPEND(("ERROR init. index temp %d: %.30s",
+				    varIndex, O2S(Tcl_GetObjResult(interp))));
+			    goto gotError;
+			}
+			CACHE_STACK_INFO();
+		    }
+		    valIndex++;
+		}
+		listTmpDepth--;
+	    }
+	    TRACE_APPEND(("jump to loop start\n"));
+	    /* loopCtTemp being 'misused' for storing the jump size */
+	    NEXT_INST_F(infoPtr->loopCtTemp, 0, 0);
+	}
+
+	TRACE_APPEND(("loop has no more iterations\n"));
+#ifdef TCL_COMPILE_DEBUG
+	NEXT_INST_F(1, 0, 0);
+#else
+	/*
+	 * FALL THROUGH
+	 */
+	pc++;
+#endif
+
+    case INST_FOREACH_END:
+	/* THIS INSTRUCTION IS ONLY CALLED AS A BREAK TARGET */
+	tmpPtr = OBJ_AT_TOS;
+	infoPtr = tmpPtr->internalRep.otherValuePtr;
+	numLists = infoPtr->numLists;
+	TRACE(("=> loop terminated\n"));
+	NEXT_INST_V(1, numLists+2, 0);
+
+    case INST_LMAP_COLLECT:
+	/*
+	 * This instruction is only issued by lmap. The stack is:
+	 *   - result
+	 *   - infoPtr
+	 *   - loop counters
+	 *   - valLists
+	 *   - collecting obj (unshared)
+	 * The instruction lappends the result to the collecting obj.
+	 */
+
+	tmpPtr = OBJ_AT_DEPTH(1);
+	infoPtr = tmpPtr->internalRep.otherValuePtr;
+	numLists = infoPtr->numLists;
+	TRACE_APPEND(("=> appending to list at depth %d\n", 3 + numLists));
+	
+	objPtr = OBJ_AT_DEPTH(3 + numLists);
+	Tcl_ListObjAppendElement(NULL, objPtr, OBJ_AT_TOS);
+	NEXT_INST_F(1, 1, 0);
     }
 
     case INST_BEGIN_CATCH4:
@@ -6241,7 +7120,8 @@ TEBCresume(
 	if (code < TCL_ERROR || code > TCL_CONTINUE) {
 	    code = TCL_CONTINUE + 1;
 	}
-	NEXT_INST_F(2*code -1, 1, 0);
+	TRACE(("\"%s\" => jump offset %d\n", O2S(OBJ_AT_TOS), 2*code-1));
+	NEXT_INST_F(2*code-1, 1, 0);
     }
 
     /*
@@ -6258,10 +7138,10 @@ TEBCresume(
 
     case INST_DICT_VERIFY:
 	dictPtr = OBJ_AT_TOS;
-	TRACE(("=> "));
+	TRACE(("\"%.30s\" => ", O2S(dictPtr)));
 	if (Tcl_DictObjSize(interp, dictPtr, &done) != TCL_OK) {
-	    TRACE_APPEND(("ERROR verifying dictionary nature of \"%s\": %s\n",
-		    O2S(OBJ_AT_DEPTH(opnd)), O2S(Tcl_GetObjResult(interp))));
+	    TRACE_APPEND(("ERROR verifying dictionary nature of \"%.30s\": %s\n",
+		    O2S(dictPtr), O2S(Tcl_GetObjResult(interp))));
 	    goto gotError;
 	}
 	TRACE_APPEND(("OK\n"));
@@ -6270,6 +7150,7 @@ TEBCresume(
     case INST_DICT_GET:
     case INST_DICT_EXISTS: {
 	register Tcl_Interp *interp2 = interp;
+	register int found;
 
 	opnd = TclGetUInt4AtPtr(pc+1);
 	TRACE(("%u => ", opnd));
@@ -6282,10 +7163,11 @@ TEBCresume(
 		    &OBJ_AT_DEPTH(opnd-1), DICT_PATH_READ);
 	    if (dictPtr == NULL) {
 		if (*pc == INST_DICT_EXISTS) {
-		    goto dictNotExists;
+		    found = 0;
+		    goto afterDictExists;
 		}
 		TRACE_WITH_OBJ((
-			"ERROR tracing dictionary path into \"%s\": ",
+			"ERROR tracing dictionary path into \"%.30s\": ",
 			O2S(OBJ_AT_DEPTH(opnd))),
 			Tcl_GetObjResult(interp));
 		goto gotError;
@@ -6294,34 +7176,40 @@ TEBCresume(
 	if (Tcl_DictObjGet(interp2, dictPtr, OBJ_AT_TOS,
 		&objResultPtr) == TCL_OK) {
 	    if (*pc == INST_DICT_EXISTS) {
-		objResultPtr = TCONST(objResultPtr ? 1 : 0);
-		TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-		NEXT_INST_V(5, opnd+1, 1);
+		found = (objResultPtr ? 1 : 0);
+		goto afterDictExists;
 	    }
-	    if (objResultPtr) {
-		TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-		NEXT_INST_V(5, opnd+1, 1);
+	    if (!objResultPtr) {
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"key \"%s\" not known in dictionary",
+			TclGetString(OBJ_AT_TOS)));
+		DECACHE_STACK_INFO();
+		Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "DICT",
+			TclGetString(OBJ_AT_TOS), NULL);
+		CACHE_STACK_INFO();
+		TRACE_ERROR(interp);
+		goto gotError;
 	    }
-	    DECACHE_STACK_INFO();
-	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
-		    "key \"%s\" not known in dictionary",
-		    TclGetString(OBJ_AT_TOS)));
-	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "DICT",
-		    TclGetString(OBJ_AT_TOS), NULL);
-	    CACHE_STACK_INFO();
-	    TRACE_WITH_OBJ(("%u => ERROR ", opnd), Tcl_GetObjResult(interp));
+	    TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+	    NEXT_INST_V(5, opnd+1, 1);
+	} else if (*pc != INST_DICT_EXISTS) {
+	    TRACE_APPEND(("ERROR reading leaf dictionary key \"%.30s\": %s",
+		    O2S(dictPtr), O2S(Tcl_GetObjResult(interp))));
+	    goto gotError;
 	} else {
-	    if (*pc == INST_DICT_EXISTS) {
-	    dictNotExists:
-		objResultPtr = TCONST(0);
-		TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-		NEXT_INST_V(5, opnd+1, 1);
-	    }
-	    TRACE_WITH_OBJ((
-		    "%u => ERROR reading leaf dictionary key \"%s\": ",
-		    opnd, O2S(dictPtr)), Tcl_GetObjResult(interp));
+	    found = 0;
 	}
-	goto gotError;
+    afterDictExists:
+	TRACE_APPEND(("%d\n", found));
+
+	/*
+	 * The INST_DICT_EXISTS instruction is usually followed by a
+	 * conditional jump, so we can take advantage of this to do some
+	 * peephole optimization (note that we're careful to not close out
+	 * someone doing something else).
+	 */
+
+	JUMP_PEEPHOLE_V(found, 5, opnd+1);
     }
 
     case INST_DICT_SET:
@@ -6395,8 +7283,8 @@ TEBCresume(
 	    if (allocateDict) {
 		TclDecrRefCount(dictPtr);
 	    }
-	    TRACE_WITH_OBJ(("%u %u => ERROR updating dictionary: ",
-		    opnd, opnd2), Tcl_GetObjResult(interp));
+	    TRACE_APPEND(("ERROR updating dictionary: %s\n",
+		    O2S(Tcl_GetObjResult(interp))));
 	    goto checkForCatch;
 	}
 
@@ -6418,8 +7306,7 @@ TEBCresume(
 	    CACHE_STACK_INFO();
 	    TclDecrRefCount(dictPtr);
 	    if (objResultPtr == NULL) {
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
@@ -6428,7 +7315,7 @@ TEBCresume(
 	    NEXT_INST_V(10, cleanup, 0);
 	}
 #endif
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_V(9, cleanup, 1);
 
     case INST_DICT_APPEND:
@@ -6461,6 +7348,7 @@ TEBCresume(
 	    if (allocateDict) {
 		TclDecrRefCount(dictPtr);
 	    }
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -6509,6 +7397,7 @@ TEBCresume(
 		    if (allocateDict) {
 			TclDecrRefCount(dictPtr);
 		    }
+		    TRACE_ERROR(interp);
 		    goto gotError;
 		}
 		Tcl_DictObjPut(NULL, dictPtr, OBJ_UNDER_TOS, valuePtr);
@@ -6518,6 +7407,7 @@ TEBCresume(
 		    if (allocateDict) {
 			TclDecrRefCount(dictPtr);
 		    }
+		    TRACE_ERROR(interp);
 		    goto gotError;
 		}
 
@@ -6554,8 +7444,7 @@ TEBCresume(
 	    CACHE_STACK_INFO();
 	    TclDecrRefCount(dictPtr);
 	    if (objResultPtr == NULL) {
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
@@ -6575,6 +7464,7 @@ TEBCresume(
 	if (Tcl_DictObjFirst(interp, dictPtr, searchPtr, &keyPtr,
 		&valuePtr, &done) != TCL_OK) {
 	    ckfree(searchPtr);
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TclNewObj(statePtr);
@@ -6610,8 +7500,9 @@ TEBCresume(
 	    PUSH_OBJECT(valuePtr);
 	    PUSH_OBJECT(keyPtr);
 	}
+	TRACE_APPEND(("\"%.30s\" \"%.30s\" %d\n",
+		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), done));
 
-#ifndef TCL_COMPILE_DEBUG
 	/*
 	 * The INST_DICT_FIRST and INST_DICT_NEXT instructsions are always
 	 * followed by a conditional jump, so we can take advantage of this to
@@ -6619,37 +7510,17 @@ TEBCresume(
 	 * out someone doing something else).
 	 */
 
-	pc += 5;
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((done ? 2 : TclGetInt1AtPtr(pc+1)), 0, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((done ? 5 : TclGetInt4AtPtr(pc+1)), 0, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((done ? TclGetInt1AtPtr(pc+1) : 2), 0, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((done ? TclGetInt4AtPtr(pc+1) : 5), 0, 0);
-	default:
-	    pc -= 5;
-	    /* fall through to non-debug handling */
-	}
-#endif
-
-	TRACE_APPEND(("\"%.30s\" \"%.30s\" %d\n",
-		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), done));
-	objResultPtr = TCONST(done);
-	/* TODO: consider opt like INST_FOREACH_STEP4 */
-	NEXT_INST_F(5, 0, 1);
+	JUMP_PEEPHOLE_F(done, 5, 0);
 
     case INST_DICT_UPDATE_START:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	opnd2 = TclGetUInt4AtPtr(pc+5);
+	TRACE(("%u => ", opnd));
 	varPtr = LOCAL(opnd);
 	duiPtr = codePtr->auxDataArrayPtr[opnd2].clientData;
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
-	TRACE(("%u => \n", opnd));
 	if (TclIsVarDirectReadable(varPtr)) {
 	    dictPtr = varPtr->value.objPtr;
 	} else {
@@ -6658,11 +7529,13 @@ TEBCresume(
 		    TCL_LEAVE_ERR_MSG, opnd);
 	    CACHE_STACK_INFO();
 	    if (dictPtr == NULL) {
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
 	if (TclListObjGetElements(interp, OBJ_AT_TOS, &length,
 		&keyPtrPtr) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	if (length != duiPtr->length) {
@@ -6671,6 +7544,7 @@ TEBCresume(
 	for (i=0 ; i<length ; i++) {
 	    if (Tcl_DictObjGet(interp, dictPtr, keyPtrPtr[i],
 		    &valuePtr) != TCL_OK) {
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    varPtr = LOCAL(duiPtr->varIndices[i]);
@@ -6686,21 +7560,23 @@ TEBCresume(
 		    valuePtr, TCL_LEAVE_ERR_MSG,
 		    duiPtr->varIndices[i]) == NULL) {
 		CACHE_STACK_INFO();
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    CACHE_STACK_INFO();
 	}
+	TRACE_APPEND(("OK\n"));
 	NEXT_INST_F(9, 0, 0);
 
     case INST_DICT_UPDATE_END:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	opnd2 = TclGetUInt4AtPtr(pc+5);
+	TRACE(("%u => ", opnd));
 	varPtr = LOCAL(opnd);
 	duiPtr = codePtr->auxDataArrayPtr[opnd2].clientData;
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
-	TRACE(("%u => ", opnd));
 	if (TclIsVarDirectReadable(varPtr)) {
 	    dictPtr = varPtr->value.objPtr;
 	} else {
@@ -6709,11 +7585,13 @@ TEBCresume(
 	    CACHE_STACK_INFO();
 	}
 	if (dictPtr == NULL) {
+	    TRACE_APPEND(("storage was unset\n"));
 	    NEXT_INST_F(9, 1, 0);
 	}
 	if (Tcl_DictObjSize(interp, dictPtr, &length) != TCL_OK
 		|| TclListObjGetElements(interp, OBJ_AT_TOS, &length,
 			&keyPtrPtr) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	allocdict = Tcl_IsShared(dictPtr);
@@ -6759,27 +7637,27 @@ TEBCresume(
 		if (allocdict) {
 		    TclDecrRefCount(dictPtr);
 		}
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
+	TRACE_APPEND(("written back\n"));
 	NEXT_INST_F(9, 1, 0);
 
     case INST_DICT_EXPAND:
 	dictPtr = OBJ_UNDER_TOS;
 	listPtr = OBJ_AT_TOS;
+	TRACE(("\"%.30s\" \"%.30s\" =>", O2S(dictPtr), O2S(listPtr)));
 	if (TclListObjGetElements(interp, listPtr, &objc, &objv) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%.30s %.30s => ERROR: ",
-		    O2S(dictPtr), O2S(listPtr)), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	objResultPtr = TclDictWithInit(interp, dictPtr, objc, objv);
 	if (objResultPtr == NULL) {
-	    TRACE_WITH_OBJ(("%.30s %.30s => ERROR: ",
-		    O2S(dictPtr), O2S(listPtr)), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
-	TRACE((" => "));
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 2, 1);
 
     case INST_DICT_RECOMBINE_STK:
@@ -6789,14 +7667,14 @@ TEBCresume(
 	TRACE(("\"%.30s\" \"%.30s\" \"%.30s\" => ",
 		O2S(varNamePtr), O2S(valuePtr), O2S(keysPtr)));
 	if (TclListObjGetElements(interp, listPtr, &objc, &objv) != TCL_OK) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    TclDecrRefCount(keysPtr);
 	    goto gotError;
 	}
 	varPtr = TclObjLookupVarEx(interp, varNamePtr, NULL,
 		TCL_LEAVE_ERR_MSG, "set", 1, 1, &arrayPtr);
 	if (varPtr == NULL) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    TclDecrRefCount(keysPtr);
 	    goto gotError;
 	}
@@ -6806,7 +7684,7 @@ TEBCresume(
 	CACHE_STACK_INFO();
 	TclDecrRefCount(keysPtr);
 	if (result != TCL_OK) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TRACE_APPEND(("OK\n"));
@@ -6820,7 +7698,7 @@ TEBCresume(
 	TRACE(("%u <- \"%.30s\" \"%.30s\" => ", opnd, O2S(valuePtr),
 		O2S(keysPtr)));
 	if (TclListObjGetElements(interp, listPtr, &objc, &objv) != TCL_OK) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	while (TclIsVarLink(varPtr)) {
@@ -6831,7 +7709,7 @@ TEBCresume(
 		objc, objv, keysPtr);
 	CACHE_STACK_INFO();
 	if (result != TCL_OK) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TRACE_APPEND(("OK\n"));
@@ -6927,10 +7805,10 @@ TEBCresume(
 	if (traceInstructions) {
 	    objPtr = Tcl_GetObjResult(interp);
 	    if ((result != TCL_ERROR) && (result != TCL_RETURN)) {
-		TRACE_APPEND(("OTHER RETURN CODE %d, result= \"%s\"\n ",
+		TRACE_APPEND(("OTHER RETURN CODE %d, result=\"%.30s\"\n ",
 			result, O2S(objPtr)));
 	    } else {
-		TRACE_APPEND(("%s, result= \"%s\"\n",
+		TRACE_APPEND(("%s, result=\"%.30s\"\n",
 			StringForResultCode(result), O2S(objPtr)));
 	    }
 	}
@@ -6943,8 +7821,8 @@ TEBCresume(
 	 */
 
     divideByZero:
-	DECACHE_STACK_INFO();
 	Tcl_SetObjResult(interp, Tcl_NewStringObj("divide by zero", -1));
+	DECACHE_STACK_INFO();
 	Tcl_SetErrorCode(interp, "ARITH", "DIVZERO", "divide by zero", NULL);
 	CACHE_STACK_INFO();
 	goto gotError;
@@ -6955,9 +7833,9 @@ TEBCresume(
 	 */
 
     exponOfZero:
-	DECACHE_STACK_INFO();
 	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"exponentiation of zero by negative power", -1));
+	DECACHE_STACK_INFO();
 	Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 		"exponentiation of zero by negative power", NULL);
 	CACHE_STACK_INFO();
@@ -7183,6 +8061,58 @@ TEBCresume(
 #undef auxObjList
 #undef catchTop
 #undef TCONST
+
+static int
+FinalizeOONext(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    CallContext *contextPtr = data[1];
+
+    /*
+     * Reset the variable lookup frame.
+     */
+
+    iPtr->varFramePtr = data[0];
+
+    /*
+     * Restore the call chain context index as we've finished the inner invoke
+     * and want to operate in the outer context again.
+     */
+
+    contextPtr->index = PTR2INT(data[2]);
+    contextPtr->skip = PTR2INT(data[3]);
+    contextPtr->oPtr->flags &= ~FILTER_HANDLING;
+    return result;
+}
+
+static int
+FinalizeOONextFilter(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    CallContext *contextPtr = data[1];
+
+    /*
+     * Reset the variable lookup frame.
+     */
+
+    iPtr->varFramePtr = data[0];
+
+    /*
+     * Restore the call chain context index as we've finished the inner invoke
+     * and want to operate in the outer context again.
+     */
+
+    contextPtr->index = PTR2INT(data[2]);
+    contextPtr->skip = PTR2INT(data[3]);
+    contextPtr->oPtr->flags |= FILTER_HANDLING;
+    return result;
+}
 
 /*
  *----------------------------------------------------------------------
@@ -8710,10 +9640,12 @@ IllegalExprOperandType(
     ClientData ptr;
     int type;
     const unsigned char opcode = *pc;
-    const char *description, *operator = operatorStrings[opcode - INST_LOR];
+    const char *description, *operator = "unknown";
 
     if (opcode == INST_EXPON) {
 	operator = "**";
+    } else if (opcode <= INST_STR_NEQ) {
+	operator = operatorStrings[opcode - INST_LOR];
     }
 
     if (GetNumberFromObj(NULL, opndPtr, &ptr, &type) != TCL_OK) {
diff --git a/generic/tclFCmd.c b/generic/tclFCmd.c
index 13377d3..6452fff 100644
--- a/generic/tclFCmd.c
+++ b/generic/tclFCmd.c
@@ -517,7 +517,7 @@ CopyRenameOneFile(
 	 * 16 bits and we get collisions. See bug #2015723.
 	 */
 
-#if !defined(WIN32) && !defined(__CYGWIN__)
+#if !defined(_WIN32) && !defined(__CYGWIN__)
 	if ((sourceStatBuf.st_ino != 0) && (targetStatBuf.st_ino != 0)) {
 	    if ((sourceStatBuf.st_ino == targetStatBuf.st_ino) &&
 		    (sourceStatBuf.st_dev == targetStatBuf.st_dev)) {
diff --git a/generic/tclIO.c b/generic/tclIO.c
index f1d85bf..ff975c3 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -165,8 +165,6 @@ static ChannelBuffer *	AllocChannelBuffer(int length);
 static void		ChannelTimerProc(ClientData clientData);
 static int		CheckChannelErrors(ChannelState *statePtr,
 			    int direction);
-static int		CheckFlush(Channel *chanPtr, ChannelBuffer *bufPtr,
-			    int newlineFlag);
 static int		CheckForDeadChannel(Tcl_Interp *interp,
 			    ChannelState *statePtr);
 static void		CheckForStdChannelsBeingClosed(Tcl_Channel chan);
@@ -194,15 +192,14 @@ static void		DiscardInputQueued(ChannelState *statePtr,
 			    int discardSavedBuffers);
 static void		DiscardOutputQueued(ChannelState *chanPtr);
 static int		DoRead(Channel *chanPtr, char *srcPtr, int slen, int allowShortReads);
-static int		DoWrite(Channel *chanPtr, const char *src, int srcLen);
 static int		DoReadChars(Channel *chan, Tcl_Obj *objPtr, int toRead,
 			    int appendFlag);
-static int		DoWriteChars(Channel *chan, const char *src, int len);
 static int		FilterInputBytes(Channel *chanPtr,
 			    GetsState *statePtr);
 static int		FlushChannel(Tcl_Interp *interp, Channel *chanPtr,
 			    int calledFromAsyncFlush);
 static int		TclGetsObjBinary(Tcl_Channel chan, Tcl_Obj *objPtr);
+static Tcl_Encoding	GetBinaryEncoding();
 static void		FreeBinaryEncoding(ClientData clientData);
 static Tcl_HashTable *	GetChannelTable(Tcl_Interp *interp);
 static int		GetInput(Channel *chanPtr);
@@ -222,18 +219,19 @@ static int		SetBlockMode(Tcl_Interp *interp, Channel *chanPtr,
 static void		StopCopy(CopyState *csPtr);
 static int		TranslateInputEOL(ChannelState *statePtr, char *dst,
 			    const char *src, int *dstLenPtr, int *srcLenPtr);
-static int		TranslateOutputEOL(ChannelState *statePtr, char *dst,
-			    const char *src, int *dstLenPtr, int *srcLenPtr);
 static void		UpdateInterest(Channel *chanPtr);
-static int		WriteBytes(Channel *chanPtr, const char *src,
-			    int srcLen);
-static int		WriteChars(Channel *chanPtr, const char *src,
-			    int srcLen);
+static int		Write(Channel *chanPtr, const char *src,
+			    int srcLen, Tcl_Encoding encoding);
 static Tcl_Obj *	FixLevelCode(Tcl_Obj *msg);
 static void		SpliceChannel(Tcl_Channel chan);
 static void		CutChannel(Tcl_Channel chan);
 static int              WillRead(Channel *chanPtr);
 
+#define WriteChars(chanPtr, src, srcLen) \
+			Write(chanPtr, src, srcLen, chanPtr->state->encoding)
+#define WriteBytes(chanPtr, src, srcLen) \
+			Write(chanPtr, src, srcLen, tclIdentityEncoding)
+
 /*
  * Simplifying helper macros. All may use their argument(s) multiple times.
  * The ANSI C "prototypes" for the macros are listed below, together with a
@@ -323,14 +321,13 @@ static int              WillRead(Channel *chanPtr);
 static void		DupChannelIntRep(Tcl_Obj *objPtr, Tcl_Obj *copyPtr);
 static int		SetChannelFromAny(Tcl_Interp *interp,
 			    Tcl_Obj *objPtr);
-static void		UpdateStringOfChannel(Tcl_Obj *objPtr);
 static void		FreeChannelIntRep(Tcl_Obj *objPtr);
 
-static const Tcl_ObjType tclChannelType = {
+static const Tcl_ObjType chanObjType = {
     "channel",			/* name for this type */
     FreeChannelIntRep,		/* freeIntRepProc */
     DupChannelIntRep,		/* dupIntRepProc */
-    NULL,			/* updateStringProc UpdateStringOfChannel */
+    NULL,			/* updateStringProc */
     NULL			/* setFromAnyProc SetChannelFromAny */
 };
 
@@ -339,7 +336,7 @@ static const Tcl_ObjType tclChannelType = {
 #define SET_CHANNELSTATE(objPtr, storePtr) \
     ((objPtr)->internalRep.twoPtrValue.ptr1 = (void *) (storePtr))
 #define GET_CHANNELINTERP(objPtr) \
-    ((Interp *) (objPtr)->internalRep.twoPtrValue.ptr2)
+    ((Tcl_Interp *) (objPtr)->internalRep.twoPtrValue.ptr2)
 #define SET_CHANNELINTERP(objPtr, storePtr) \
     ((objPtr)->internalRep.twoPtrValue.ptr2 = (void *) (storePtr))
 
@@ -1581,11 +1578,7 @@ Tcl_CreateChannel(
     statePtr->timer		= NULL;
     statePtr->csPtrR		= NULL;
     statePtr->csPtrW		= NULL;
-
     statePtr->outputStage	= NULL;
-    if ((statePtr->encoding != NULL) && GotFlag(statePtr, TCL_WRITABLE)) {
-	statePtr->outputStage = ckalloc(statePtr->bufSize + 2);
-    }
 
     /*
      * As we are creating the channel, it is obviously the top for now.
@@ -2838,10 +2831,6 @@ CloseChannel(
 	}
 
 	Tcl_FreeEncoding(statePtr->encoding);
-	if (statePtr->outputStage != NULL) {
-	    ckfree(statePtr->outputStage);
-	    statePtr->outputStage = NULL;
-	}
     }
 
     /*
@@ -3778,7 +3767,7 @@ Tcl_Write(
     if (srcLen < 0) {
 	srcLen = strlen(src);
     }
-    return DoWrite(chanPtr, src, srcLen);
+    return WriteBytes(chanPtr, src, srcLen);
 }
 
 /*
@@ -3869,82 +3858,40 @@ Tcl_WriteChars(
     int len)			/* Length of string in bytes, or < 0 for
 				 * strlen(). */
 {
-    ChannelState *statePtr;	/* State info for channel */
-
-    statePtr = ((Channel *) chan)->state;
+    Channel *chanPtr = (Channel *) chan;
+    ChannelState *statePtr = chanPtr->state;	/* State info for channel */
+    int result;
+    Tcl_Obj *objPtr;
 
     if (CheckChannelErrors(statePtr, TCL_WRITABLE) != 0) {
 	return -1;
     }
 
-    return DoWriteChars((Channel *) chan, src, len);
-}
-
-/*
- *---------------------------------------------------------------------------
- *
- * DoWriteChars --
- *
- *	Takes a sequence of UTF-8 characters and converts them for output
- *	using the channel's current encoding, may queue the buffer for output
- *	if it gets full, and also remembers whether the current buffer is
- *	ready e.g. if it contains a newline and we are in line buffering mode.
- *	Compensates stacking, i.e. will redirect the data from the specified
- *	channel to the topmost channel in a stack.
- *
- * Results:
- *	The number of bytes written or -1 in case of error. If -1,
- *	Tcl_GetErrno will return the error code.
- *
- * Side effects:
- *	May buffer up output and may cause output to be produced on the
- *	channel.
- *
- *----------------------------------------------------------------------
- */
-
-static int
-DoWriteChars(
-    Channel *chanPtr,		/* The channel to buffer output for. */
-    const char *src,		/* UTF-8 characters to queue in output
-				 * buffer. */
-    int len)			/* Length of string in bytes, or < 0 for
-				 * strlen(). */
-{
-    /*
-     * Always use the topmost channel of the stack
-     */
-
-    ChannelState *statePtr;	/* State info for channel */
-
-    statePtr = chanPtr->state;
     chanPtr = statePtr->topChanPtr;
 
     if (len < 0) {
 	len = strlen(src);
     }
-    if (statePtr->encoding == NULL) {
-	/*
-	 * Inefficient way to convert UTF-8 to byte-array, but the code
-	 * parallels the way it is done for objects.
-	 * Special case for 1-byte (used by eg [puts] for the \n) could
-	 * be extended to more efficient translation of the src string.
-	 */
-
-	int result;
+    if (statePtr->encoding) {
+	return WriteChars(chanPtr, src, len);
+    }
 
-	if ((len == 1) && (UCHAR(*src) < 0xC0)) {
-	    result = WriteBytes(chanPtr, src, len);
-	} else {
-	    Tcl_Obj *objPtr = Tcl_NewStringObj(src, len);
+    /*
+     * Inefficient way to convert UTF-8 to byte-array, but the code
+     * parallels the way it is done for objects.  Special case for 1-byte
+     * (used by eg [puts] for the \n) could be extended to more efficient
+     * translation of the src string.
+     */
 
-	    src = (char *) Tcl_GetByteArrayFromObj(objPtr, &len);
-	    result = WriteBytes(chanPtr, src, len);
-	    TclDecrRefCount(objPtr);
-	}
-	return result;
+    if ((len == 1) && (UCHAR(*src) < 0xC0)) {
+	return WriteBytes(chanPtr, src, len);
     }
-    return WriteChars(chanPtr, src, len);
+
+    objPtr = Tcl_NewStringObj(src, len);
+    src = (char *) Tcl_GetByteArrayFromObj(objPtr, &len);
+    result = WriteBytes(chanPtr, src, len);
+    TclDecrRefCount(objPtr);
+    return result;
 }
 
 /*
@@ -4036,110 +3983,9 @@ WillRead(
 /*
  *----------------------------------------------------------------------
  *
- * WriteBytes --
- *
- *	Write a sequence of bytes into an output buffer, may queue the buffer
- *	for output if it gets full, and also remembers whether the current
- *	buffer is ready e.g. if it contains a newline and we are in line
- *	buffering mode.
- *
- * Results:
- *	The number of bytes written or -1 in case of error. If -1,
- *	Tcl_GetErrno will return the error code.
+ * Write --
  *
- * Side effects:
- *	May buffer up output and may cause output to be produced on the
- *	channel.
- *
- *----------------------------------------------------------------------
- */
-
-static int
-WriteBytes(
-    Channel *chanPtr,		/* The channel to buffer output for. */
-    const char *src,		/* Bytes to write. */
-    int srcLen)			/* Number of bytes to write. */
-{
-    ChannelState *statePtr = chanPtr->state;
-				/* State info for channel */
-    ChannelBuffer *bufPtr;
-    char *dst;
-    int dstMax, sawLF, savedLF, total, dstLen, toWrite, translate;
-
-    if (srcLen) {
-        WillWrite(chanPtr);
-    }
-
-    total = 0;
-    sawLF = 0;
-    savedLF = 0;
-    translate = GotFlag(statePtr, CHANNEL_LINEBUFFERED)
-	    || (statePtr->outputTranslation != TCL_TRANSLATE_LF);
-
-    /*
-     * Loop over all bytes in src, storing them in output buffer with proper
-     * EOL translation.
-     */
-
-    while (srcLen + savedLF > 0) {
-	bufPtr = statePtr->curOutPtr;
-	if (bufPtr == NULL) {
-	    bufPtr = AllocChannelBuffer(statePtr->bufSize);
-	    statePtr->curOutPtr = bufPtr;
-	}
-	dst = InsertPoint(bufPtr);
-	dstMax = SpaceLeft(bufPtr);
-	dstLen = dstMax;
-
-	toWrite = dstLen;
-	if (toWrite > srcLen) {
-	    toWrite = srcLen;
-	}
-
-	if (translate) {
-	    if (savedLF) {
-		/*
-		 * A '\n' was left over from last call to TranslateOutputEOL()
-		 * and we need to store it in this buffer. If the channel is
-		 * line-based, we will need to flush it.
-		 */
-
-		*dst++ = '\n';
-		dstLen--;
-		sawLF++;
-	    }
-	    if (TranslateOutputEOL(statePtr, dst, src, &dstLen, &toWrite)) {
-		sawLF++;
-	    }
-	    dstLen += savedLF;
-	    savedLF = 0;
-	    if (dstLen > dstMax) {
-		savedLF = 1;
-		dstLen = dstMax;
-	    }
-	} else {
-	    memcpy(dst, src, toWrite);
-	    dstLen = toWrite;
-	}
-
-	bufPtr->nextAdded += dstLen;
-	if (CheckFlush(chanPtr, bufPtr, sawLF) != 0) {
-	    return -1;
-	}
-	total += dstLen;
-	src += toWrite;
-	srcLen -= toWrite;
-	sawLF = 0;
-    }
-    return total;
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * WriteChars --
- *
- *	Convert UTF-8 bytes to the channel's external encoding and write the
+ *	Convert srcLen bytes starting at src according to encoding and write
  *	produced bytes into an output buffer, may queue the buffer for output
  *	if it gets full, and also remembers whether the current buffer is
  *	ready e.g. if it contains a newline and we are in line buffering mode.
@@ -4156,381 +4002,163 @@ WriteBytes(
  */
 
 static int
-WriteChars(
+Write(
     Channel *chanPtr,		/* The channel to buffer output for. */
     const char *src,		/* UTF-8 string to write. */
-    int srcLen)			/* Length of UTF-8 string in bytes. */
+    int srcLen,			/* Length of UTF-8 string in bytes. */
+    Tcl_Encoding encoding)
 {
     ChannelState *statePtr = chanPtr->state;
 				/* State info for channel */
-    ChannelBuffer *bufPtr;
-    char *dst, *stage;
-    int saved, savedLF, sawLF, total, dstLen, stageMax, dstWrote;
-    int stageLen, toWrite, stageRead, endEncoding, result;
-    int consumedSomething, translate;
-    Tcl_Encoding encoding;
-    char safe[BUFFER_PADDING];
+    char *nextNewLine = NULL;
+    int endEncoding, saved = 0, total = 0, flushed = 0, needNlFlush = 0;
 
     if (srcLen) {
         WillWrite(chanPtr);
     }
 
-    total = 0;
-    sawLF = 0;
-    savedLF = 0;
-    saved = 0;
-    encoding = statePtr->encoding;
-
     /*
      * Write the terminated escape sequence even if srcLen is 0.
      */
 
     endEncoding = ((statePtr->outputEncodingFlags & TCL_ENCODING_END) != 0);
 
-    translate = GotFlag(statePtr, CHANNEL_LINEBUFFERED)
-	    || (statePtr->outputTranslation != TCL_TRANSLATE_LF);
-
-    /*
-     * Loop over all UTF-8 characters in src, storing them in staging buffer
-     * with proper EOL translation.
-     */
+    if (GotFlag(statePtr, CHANNEL_LINEBUFFERED)
+	    || (statePtr->outputTranslation != TCL_TRANSLATE_LF)) {
+	nextNewLine = memchr(src, '\n', srcLen);
+    }
 
-    consumedSomething = 1;
-    while (consumedSomething && (srcLen + savedLF + endEncoding > 0)) {
-	consumedSomething = 0;
-	stage = statePtr->outputStage;
-	stageMax = statePtr->bufSize;
-	stageLen = stageMax;
+    while (srcLen + saved + endEncoding > 0) {
+	ChannelBuffer *bufPtr;
+	char *dst, safe[BUFFER_PADDING];
+	int result, srcRead, dstLen, dstWrote, srcLimit = srcLen;
 
-	toWrite = stageLen;
-	if (toWrite > srcLen) {
-	    toWrite = srcLen;
+	if (nextNewLine) {
+	    srcLimit = nextNewLine - src;
 	}
-
-	if (translate) {
-	    if (savedLF) {
-		/*
-		 * A '\n' was left over from last call to TranslateOutputEOL()
-		 * and we need to store it in the staging buffer. If the
-		 * channel is line-based, we will need to flush the output
-		 * buffer (after translating the staging buffer).
-		 */
-
-		*stage++ = '\n';
-		stageLen--;
-		sawLF++;
-	    }
-	    if (TranslateOutputEOL(statePtr, stage, src, &stageLen,
-		    &toWrite)) {
-		sawLF++;
-	    }
-
-	    stage -= savedLF;
-	    stageLen += savedLF;
-	    savedLF = 0;
-
-	    if (stageLen > stageMax) {
-		savedLF = 1;
-		stageLen = stageMax;
-	    }
-	} else {
-	    memcpy(stage, src, toWrite);
-	    stageLen = toWrite;
+	
+	/* Get space to write into */
+	bufPtr = statePtr->curOutPtr;
+	if (bufPtr == NULL) {
+	    bufPtr = AllocChannelBuffer(statePtr->bufSize);
+	    statePtr->curOutPtr = bufPtr;
 	}
-	src += toWrite;
-	srcLen -= toWrite;
-
-	/*
-	 * Loop over all UTF-8 characters in staging buffer, converting them
-	 * to external encoding, storing them in output buffer.
-	 */
-
-	while (stageLen + saved + endEncoding > 0) {
-	    bufPtr = statePtr->curOutPtr;
-	    if (bufPtr == NULL) {
-		bufPtr = AllocChannelBuffer(statePtr->bufSize);
-		statePtr->curOutPtr = bufPtr;
-	    }
-	    dst = InsertPoint(bufPtr);
-	    dstLen = SpaceLeft(bufPtr);
-
-	    if (saved != 0) {
-		/*
-		 * Here's some translated bytes left over from the last buffer
-		 * that we need to stick at the beginning of this buffer.
-		 */
-
-		memcpy(dst, safe, (size_t) saved);
-		bufPtr->nextAdded += saved;
-		dst += saved;
-		dstLen -= saved;
-		saved = 0;
-	    }
-
-	    result = Tcl_UtfToExternal(NULL, encoding, stage, stageLen,
-		    statePtr->outputEncodingFlags,
-		    &statePtr->outputEncodingState, dst,
-		    dstLen + BUFFER_PADDING, &stageRead, &dstWrote, NULL);
-
+	if (saved) {
 	    /*
-	     * Fix for SF #506297, reported by Martin Forssen
-	     * <ruric@users.sourceforge.net>.
-	     *
-	     * The encoding chosen in the script exposing the bug writes out
-	     * three intro characters when TCL_ENCODING_START is set, but does
-	     * not consume any input as TCL_ENCODING_END is cleared. As some
-	     * output was generated the enclosing loop calls UtfToExternal
-	     * again, again with START set. Three more characters in the out
-	     * and still no use of input ... To break this infinite loop we
-	     * remove TCL_ENCODING_START from the set of flags after the first
-	     * call (no condition is required, the later calls remove an unset
-	     * flag, which is a no-op). This causes the subsequent calls to
-	     * UtfToExternal to consume and convert the actual input.
+	     * Here's some translated bytes left over from the last buffer
+	     * that we need to stick at the beginning of this buffer.
 	     */
 
-	    statePtr->outputEncodingFlags &= ~TCL_ENCODING_START;
+	    memcpy(InsertPoint(bufPtr), safe, (size_t) saved);
+	    bufPtr->nextAdded += saved;
+	    saved = 0;
+	}
+	dst = InsertPoint(bufPtr);
+	dstLen = SpaceLeft(bufPtr);
+
+	result = Tcl_UtfToExternal(NULL, encoding, src, srcLimit,
+		statePtr->outputEncodingFlags,
+		&statePtr->outputEncodingState, dst,
+		dstLen + BUFFER_PADDING, &srcRead, &dstWrote, NULL);
+
+	/* See chan-io-1.[89]. Tcl Bug 506297. */
+	statePtr->outputEncodingFlags &= ~TCL_ENCODING_START;
+	
+	if ((result != TCL_OK) && (srcRead + dstWrote == 0)) {
+	    /* We're reading from invalid/incomplete UTF-8 */
+	    if (total == 0) {
+		Tcl_SetErrno(EINVAL);
+		return -1;
+	    }
+	    break;
+	}
 
-	    /*
-	     * The following code must be executed only when result is not 0.
-	     */
+	bufPtr->nextAdded += dstWrote;
+	src += srcRead;
+	srcLen -= srcRead;
+	total += dstWrote;
+	dst += dstWrote;
+	dstLen -= dstWrote;
 
-	    if ((result != 0) && (stageRead + dstWrote == 0)) {
-		/*
-		 * We have an incomplete UTF-8 character at the end of the
-		 * staging buffer. It will get moved to the beginning of the
-		 * staging buffer followed by more bytes from src.
-		 */
+	if (src == nextNewLine && dstLen > 0) {
+	    static char crln[3] = "\r\n";
+	    char *nl = NULL;
+	    int nlLen = 0;
 
-		src -= stageLen;
-		srcLen += stageLen;
-		stageLen = 0;
-		savedLF = 0;
+	    switch (statePtr->outputTranslation) {
+	    case TCL_TRANSLATE_LF:
+		nl = crln + 1;
+		nlLen = 1;
+		break;
+	    case TCL_TRANSLATE_CR:
+		nl = crln;
+		nlLen = 1;
+		break;
+	    case TCL_TRANSLATE_CRLF:
+		nl = crln;
+		nlLen = 2;
+		break;
+	    default:
+		Tcl_Panic("unknown output translation requested");
 		break;
 	    }
-	    bufPtr->nextAdded += dstWrote;
-	    if (IsBufferOverflowing(bufPtr)) {
-		/*
-		 * When translating from UTF-8 to external encoding, we
-		 * allowed the translation to produce a character that crossed
-		 * the end of the output buffer, so that we would get a
-		 * completely full buffer before flushing it. The extra bytes
-		 * will be moved to the beginning of the next buffer.
-		 */
+	
+	    result |= Tcl_UtfToExternal(NULL, encoding, nl, nlLen,
+		statePtr->outputEncodingFlags,
+		&statePtr->outputEncodingState, dst,
+		dstLen + BUFFER_PADDING, &srcRead, &dstWrote, NULL);
 
-		saved = -SpaceLeft(bufPtr);
-		memcpy(safe, dst + dstLen, (size_t) saved);
-		bufPtr->nextAdded = bufPtr->bufLength;
-	    }
-	    if (CheckFlush(chanPtr, bufPtr, sawLF) != 0) {
-		return -1;
+	    if (srcRead != nlLen) {
+		Tcl_Panic("Can This Happen?");
 	    }
 
+	    bufPtr->nextAdded += dstWrote;
+	    src++;
+	    srcLen--;
 	    total += dstWrote;
-	    stage += stageRead;
-	    stageLen -= stageRead;
-	    sawLF = 0;
-
-	    consumedSomething = 1;
+	    dst += dstWrote;
+	    dstLen -= dstWrote;
+	    nextNewLine = memchr(src, '\n', srcLen);
+	    needNlFlush = 1;
+	}
 
+	if (IsBufferOverflowing(bufPtr)) {
 	    /*
-	     * If all translated characters are written to the buffer,
-	     * endEncoding is set to 0 because the escape sequence may be
-	     * output.
+	     * When translating from UTF-8 to external encoding, we
+	     * allowed the translation to produce a character that crossed
+	     * the end of the output buffer, so that we would get a
+	     * completely full buffer before flushing it. The extra bytes
+	     * will be moved to the beginning of the next buffer.
 	     */
 
-	    if ((stageLen + saved == 0) && (result == 0)) {
-		endEncoding = 0;
-	    }
-	}
-    }
-
-    /*
-     * If nothing was written and it happened because there was no progress in
-     * the UTF conversion, we throw an error.
-     */
-
-    if (!consumedSomething && (total == 0)) {
-	Tcl_SetErrno(EINVAL);
-	return -1;
-    }
-    return total;
-}
-
-/*
- *---------------------------------------------------------------------------
- *
- * TranslateOutputEOL --
- *
- *	Helper function for WriteBytes() and WriteChars(). Converts the '\n'
- *	characters in the source buffer into the appropriate EOL form
- *	specified by the output translation mode.
- *
- *	EOL translation stops either when the source buffer is empty or the
- *	output buffer is full.
- *
- *	When converting to CRLF mode and there is only 1 byte left in the
- *	output buffer, this routine stores the '\r' in the last byte and then
- *	stores the '\n' in the byte just past the end of the buffer. The
- *	caller is responsible for passing in a buffer that is large enough to
- *	hold the extra byte.
- *
- * Results:
- *	The return value is 1 if a '\n' was translated from the source buffer,
- *	or 0 otherwise -- this can be used by the caller to decide to flush a
- *	line-based channel even though the channel buffer is not full.
- *
- *	*dstLenPtr is filled with how many bytes of the output buffer were
- *	used. As mentioned above, this can be one more that the output
- *	buffer's specified length if a CRLF was stored.
- *
- *	*srcLenPtr is filled with how many bytes of the source buffer were
- *	consumed.
- *
- * Side effects:
- *	It may be obvious, but bears mentioning that when converting in CRLF
- *	mode (which requires two bytes of storage in the output buffer), the
- *	number of bytes consumed from the source buffer will be less than the
- *	number of bytes stored in the output buffer.
- *
- *---------------------------------------------------------------------------
- */
-
-static int
-TranslateOutputEOL(
-    ChannelState *statePtr,	/* Channel being read, for translation and
-				 * buffering modes. */
-    char *dst,			/* Output buffer filled with UTF-8 chars by
-				 * applying appropriate EOL translation to
-				 * source characters. */
-    const char *src,		/* Source UTF-8 characters. */
-    int *dstLenPtr,		/* On entry, the maximum length of output
-				 * buffer in bytes. On exit, the number of
-				 * bytes actually used in output buffer. */
-    int *srcLenPtr)		/* On entry, the length of source buffer. On
-				 * exit, the number of bytes read from the
-				 * source buffer. */
-{
-    char *dstEnd;
-    int srcLen, newlineFound;
-
-    newlineFound = 0;
-    srcLen = *srcLenPtr;
-
-    switch (statePtr->outputTranslation) {
-    case TCL_TRANSLATE_LF:
-	for (dstEnd = dst + srcLen; dst < dstEnd; ) {
-	    if (*src == '\n') {
-		newlineFound = 1;
-	    }
-	    *dst++ = *src++;
+	    saved = -SpaceLeft(bufPtr);
+	    memcpy(safe, dst + dstLen, (size_t) saved);
+	    bufPtr->nextAdded = bufPtr->bufLength;
 	}
-	*dstLenPtr = srcLen;
-	break;
-    case TCL_TRANSLATE_CR:
-	for (dstEnd = dst + srcLen; dst < dstEnd;) {
-	    if (*src == '\n') {
-		*dst++ = '\r';
-		newlineFound = 1;
-		src++;
-	    } else {
-		*dst++ = *src++;
-	    }
-	}
-	*dstLenPtr = srcLen;
-	break;
-    case TCL_TRANSLATE_CRLF: {
-	/*
-	 * Since this causes the number of bytes to grow, we start off trying
-	 * to put 'srcLen' bytes into the output buffer, but allow it to store
-	 * more bytes, as long as there's still source bytes and room in the
-	 * output buffer.
-	 */
-
-	char *dstStart, *dstMax;
-	const char *srcStart;
-
-	dstStart = dst;
-	dstMax = dst + *dstLenPtr;
 
-	srcStart = src;
-
-	if (srcLen < *dstLenPtr) {
-	    dstEnd = dst + srcLen;
-	} else {
-	    dstEnd = dst + *dstLenPtr;
-	}
-	while (dst < dstEnd) {
-	    if (*src == '\n') {
-		if (dstEnd < dstMax) {
-		    dstEnd++;
-		}
-		*dst++ = '\r';
-		newlineFound = 1;
-	    }
-	    *dst++ = *src++;
+	if ((srcLen + saved == 0) && (result == TCL_OK)) {
+	    endEncoding = 0;
 	}
-	*srcLenPtr = src - srcStart;
-	*dstLenPtr = dst - dstStart;
-	break;
-    }
-    default:
-	break;
-    }
-    return newlineFound;
-}
-
-/*
- *---------------------------------------------------------------------------
- *
- * CheckFlush --
- *
- *	Helper function for WriteBytes() and WriteChars(). If the channel
- *	buffer is ready to be flushed, flush it.
- *
- * Results:
- *	The return value is -1 if there was a problem flushing the channel
- *	buffer, or 0 otherwise.
- *
- * Side effects:
- *	The buffer will be recycled if it is flushed.
- *
- *---------------------------------------------------------------------------
- */
-
-static int
-CheckFlush(
-    Channel *chanPtr,		/* Channel being read, for buffering mode. */
-    ChannelBuffer *bufPtr,	/* Channel buffer to possibly flush. */
-    int newlineFlag)		/* Non-zero if a the channel buffer contains a
-				 * newline. */
-{
-    ChannelState *statePtr = chanPtr->state;
-				/* State info for channel */
-
-    /*
-     * The current buffer is ready for output:
-     * 1. if it is full.
-     * 2. if it contains a newline and this channel is line-buffered.
-     * 3. if it contains any output and this channel is unbuffered.
-     */
 
-    if (!GotFlag(statePtr, BUFFER_READY)) {
 	if (IsBufferFull(bufPtr)) {
-	    SetFlag(statePtr, BUFFER_READY);
-	} else if (GotFlag(statePtr, CHANNEL_LINEBUFFERED)) {
-	    if (newlineFlag != 0) {
-		SetFlag(statePtr, BUFFER_READY);
+	    if (FlushChannel(NULL, chanPtr, 0) != 0) {
+		return -1;
+	    }
+	    flushed += statePtr->bufSize;
+	    if (saved == 0 || src[-1] != '\n') {
+		needNlFlush = 0;
 	    }
-	} else if (GotFlag(statePtr, CHANNEL_UNBUFFERED)) {
-	    SetFlag(statePtr, BUFFER_READY);
 	}
     }
-    if (GotFlag(statePtr, BUFFER_READY)) {
+    if ((flushed < total) && (GotFlag(statePtr, CHANNEL_UNBUFFERED) ||
+	    (needNlFlush && GotFlag(statePtr, CHANNEL_LINEBUFFERED)))) {
+	SetFlag(statePtr, BUFFER_READY);
 	if (FlushChannel(NULL, chanPtr, 0) != 0) {
 	    return -1;
 	}
     }
-    return 0;
+
+    return total;
 }
 
 /*
@@ -4656,16 +4284,7 @@ Tcl_GetsObj(
      */
 
     if (encoding == NULL) {
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
-
-	if (tsdPtr->binaryEncoding == NULL) {
-	    tsdPtr->binaryEncoding = Tcl_GetEncoding(NULL, "iso8859-1");
-	    Tcl_CreateThreadExitHandler(FreeBinaryEncoding, NULL);
-	}
-	encoding = tsdPtr->binaryEncoding;
-	if (encoding == NULL) {
-	    Tcl_Panic("attempted gets on binary channel where no iso8859-1 encoding available");
-	}
+	encoding = GetBinaryEncoding();
     }
 
     /*
@@ -5231,6 +4850,21 @@ FreeBinaryEncoding(
 	tsdPtr->binaryEncoding = NULL;
     }
 }
+
+static Tcl_Encoding
+GetBinaryEncoding()
+{
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+
+    if (tsdPtr->binaryEncoding == NULL) {
+	tsdPtr->binaryEncoding = Tcl_GetEncoding(NULL, "iso8859-1");
+	Tcl_CreateThreadExitHandler(FreeBinaryEncoding, NULL);
+    }
+    if (tsdPtr->binaryEncoding == NULL) {
+	Tcl_Panic("binary encoding is not available");
+    }
+    return tsdPtr->binaryEncoding;
+}
 
 /*
  *---------------------------------------------------------------------------
@@ -7594,14 +7228,6 @@ Tcl_SetChannelBufferSize(
 
     statePtr = ((Channel *) chan)->state;
     statePtr->bufSize = sz;
-
-    if (statePtr->outputStage != NULL) {
-	ckfree(statePtr->outputStage);
-	statePtr->outputStage = NULL;
-    }
-    if ((statePtr->encoding != NULL) && GotFlag(statePtr, TCL_WRITABLE)) {
-	statePtr->outputStage = ckalloc(statePtr->bufSize + 2);
-    }
 }
 
 /*
@@ -8242,17 +7868,6 @@ Tcl_SetChannelOption(
 	statePtr->inQueueTail = NULL;
     }
 
-    /*
-     * If encoding or bufsize changes, need to update output staging buffer.
-     */
-
-    if (statePtr->outputStage != NULL) {
-	ckfree(statePtr->outputStage);
-	statePtr->outputStage = NULL;
-    }
-    if ((statePtr->encoding != NULL) && GotFlag(statePtr, TCL_WRITABLE)) {
-	statePtr->outputStage = ckalloc(statePtr->bufSize + 2);
-    }
     return TCL_OK;
 }
 
@@ -9399,9 +9014,9 @@ CopyData(
 	}
 
 	if (outBinary || sameEncoding) {
-	    sizeb = DoWrite(outStatePtr->topChanPtr, buffer, sizeb);
+	    sizeb = WriteBytes(outStatePtr->topChanPtr, buffer, sizeb);
 	} else {
-	    sizeb = DoWriteChars(outStatePtr->topChanPtr, buffer, sizeb);
+	    sizeb = WriteChars(outStatePtr->topChanPtr, buffer, sizeb);
 	}
 
 	/*
@@ -9953,162 +9568,6 @@ CopyBuffer(
 /*
  *----------------------------------------------------------------------
  *
- * DoWrite --
- *
- *	Puts a sequence of characters into an output buffer, may queue the
- *	buffer for output if it gets full, and also remembers whether the
- *	current buffer is ready e.g. if it contains a newline and we are in
- *	line buffering mode.
- *
- * Results:
- *	The number of bytes written or -1 in case of error. If -1,
- *	Tcl_GetErrno will return the error code.
- *
- * Side effects:
- *	May buffer up output and may cause output to be produced on the
- *	channel.
- *
- *----------------------------------------------------------------------
- */
-
-static int
-DoWrite(
-    Channel *chanPtr,		/* The channel to buffer output for. */
-    const char *src,		/* Data to write. */
-    int srcLen)			/* Number of bytes to write. */
-{
-    ChannelState *statePtr = chanPtr->state;
-				/* State info for channel */
-    ChannelBuffer *outBufPtr;	/* Current output buffer. */
-    int foundNewline;		/* Did we find a newline in output? */
-    char *dPtr;
-    const char *sPtr;		/* Search variables for newline. */
-    int crsent;			/* In CRLF eol translation mode, remember the
-				 * fact that a CR was output to the channel
-				 * without its following NL. */
-    int i;			/* Loop index for newline search. */
-    int destCopied;		/* How many bytes were used in this
-				 * destination buffer to hold the output? */
-    int totalDestCopied;	/* How many bytes total were copied to the
-				 * channel buffer? */
-    int srcCopied;		/* How many bytes were copied from the source
-				 * string? */
-    char *destPtr;		/* Where in line to copy to? */
-
-    /*
-     * If we are in network (or windows) translation mode, record the fact
-     * that we have not yet sent a CR to the channel.
-     */
-
-    crsent = 0;
-
-    /*
-     * Loop filling buffers and flushing them until all output has been
-     * consumed.
-     */
-
-    srcCopied = 0;
-    totalDestCopied = 0;
-
-    while (srcLen > 0) {
-	/*
-	 * Make sure there is a current output buffer to accept output.
-	 */
-
-	if (statePtr->curOutPtr == NULL) {
-	    statePtr->curOutPtr = AllocChannelBuffer(statePtr->bufSize);
-	}
-
-	outBufPtr = statePtr->curOutPtr;
-
-	destCopied = SpaceLeft(outBufPtr);
-	if (destCopied > srcLen) {
-	    destCopied = srcLen;
-	}
-
-	destPtr = InsertPoint(outBufPtr);
-	switch (statePtr->outputTranslation) {
-	case TCL_TRANSLATE_LF:
-	    srcCopied = destCopied;
-	    memcpy(destPtr, src, (size_t) destCopied);
-	    break;
-	case TCL_TRANSLATE_CR:
-	    srcCopied = destCopied;
-	    memcpy(destPtr, src, (size_t) destCopied);
-	    for (dPtr = destPtr; dPtr < destPtr + destCopied; dPtr++) {
-		if (*dPtr == '\n') {
-		    *dPtr = '\r';
-		}
-	    }
-	    break;
-	case TCL_TRANSLATE_CRLF:
-	    for (srcCopied = 0, dPtr = destPtr, sPtr = src;
-		    dPtr < destPtr + destCopied;
-		    dPtr++, sPtr++, srcCopied++) {
-		if (*sPtr == '\n') {
-		    if (crsent) {
-			*dPtr = '\n';
-			crsent = 0;
-		    } else {
-			*dPtr = '\r';
-			crsent = 1;
-			sPtr--, srcCopied--;
-		    }
-		} else {
-		    *dPtr = *sPtr;
-		}
-	    }
-	    break;
-	case TCL_TRANSLATE_AUTO:
-	    Tcl_Panic("Tcl_Write: AUTO output translation mode not supported");
-	default:
-	    Tcl_Panic("Tcl_Write: unknown output translation mode");
-	}
-
-	/*
-	 * The current buffer is ready for output if it is full, or if it
-	 * contains a newline and this channel is line-buffered, or if it
-	 * contains any output and this channel is unbuffered.
-	 */
-
-	outBufPtr->nextAdded += destCopied;
-	if (!GotFlag(statePtr, BUFFER_READY)) {
-	    if (IsBufferFull(outBufPtr)) {
-		SetFlag(statePtr, BUFFER_READY);
-	    } else if (GotFlag(statePtr, CHANNEL_LINEBUFFERED)) {
-		for (sPtr = src, i = 0, foundNewline = 0;
-			(i < srcCopied) && (!foundNewline);
-			i++, sPtr++) {
-		    if (*sPtr == '\n') {
-			foundNewline = 1;
-			break;
-		    }
-		}
-		if (foundNewline) {
-		    SetFlag(statePtr, BUFFER_READY);
-		}
-	    } else if (GotFlag(statePtr, CHANNEL_UNBUFFERED)) {
-		SetFlag(statePtr, BUFFER_READY);
-	    }
-	}
-
-	totalDestCopied += srcCopied;
-	src += srcCopied;
-	srcLen -= srcCopied;
-
-	if (GotFlag(statePtr, BUFFER_READY)) {
-	    if (FlushChannel(NULL, chanPtr, 0) != 0) {
-		return -1;
-	    }
-	}
-    } /* Closes "while" */
-
-    return totalDestCopied;
-}
-
-/*
- *----------------------------------------------------------------------
- *
  * CopyEventProc --
  *
  *	This routine is invoked as a channel event handler for the background
@@ -11331,12 +10790,11 @@ DupChannelIntRep(
 				 * currently have an internal rep.*/
 {
     ChannelState *statePtr  = GET_CHANNELSTATE(srcPtr);
-    Interp *interpPtr = GET_CHANNELINTERP(srcPtr);
 
     SET_CHANNELSTATE(copyPtr, statePtr);
-    SET_CHANNELINTERP(copyPtr, interpPtr);
+    SET_CHANNELINTERP(copyPtr, GET_CHANNELINTERP(srcPtr));
     Tcl_Preserve(statePtr);
-    copyPtr->typePtr = &tclChannelType;
+    copyPtr->typePtr = srcPtr->typePtr;
 }
 
 /*
@@ -11362,43 +10820,29 @@ SetChannelFromAny(
     register Tcl_Obj *objPtr)	/* The object to convert. */
 {
     ChannelState *statePtr;
-    Interp *interpPtr;
 
     if (interp == NULL) {
 	return TCL_ERROR;
     }
-    if (objPtr->typePtr == &tclChannelType) {
+    if (objPtr->typePtr == &chanObjType) {
 	/*
 	 * The channel is valid until any call to DetachChannel occurs.
 	 * Ensure consistency checks are done.
 	 */
 
 	statePtr = GET_CHANNELSTATE(objPtr);
-	interpPtr = GET_CHANNELINTERP(objPtr);
 	if (GotFlag(statePtr, CHANNEL_TAINTED|CHANNEL_CLOSED)) {
 	    ResetFlag(statePtr, CHANNEL_TAINTED);
 	    Tcl_Release(statePtr);
-	    UpdateStringOfChannel(objPtr);
 	    objPtr->typePtr = NULL;
-	} else if (interpPtr != (Interp*) interp) {
+	} else if (interp != GET_CHANNELINTERP(objPtr)) {
 	    Tcl_Release(statePtr);
-	    UpdateStringOfChannel(objPtr);
 	    objPtr->typePtr = NULL;
 	}
     }
-    if (objPtr->typePtr != &tclChannelType) {
-	Tcl_Channel chan;
-
-	/*
-	 * We need a valid string with which to check for a valid channel, but
-	 * make sure not to free internal rep until validated. [Bug 1847044]
-	 */
+    if (objPtr->typePtr != &chanObjType) {
+	Tcl_Channel chan = Tcl_GetChannel(interp, TclGetString(objPtr), NULL);
 
-	if ((objPtr->typePtr != NULL) && (objPtr->bytes == NULL)) {
-	    objPtr->typePtr->updateStringProc(objPtr);
-	}
-
-	chan = Tcl_GetChannel(interp, objPtr->bytes, NULL);
 	if (chan == NULL) {
 	    return TCL_ERROR;
 	}
@@ -11408,7 +10852,7 @@ SetChannelFromAny(
 	Tcl_Preserve(statePtr);
 	SET_CHANNELSTATE(objPtr, statePtr);
 	SET_CHANNELINTERP(objPtr, interp);
-	objPtr->typePtr = &tclChannelType;
+	objPtr->typePtr = &chanObjType;
     }
     return TCL_OK;
 }
@@ -11416,45 +10860,6 @@ SetChannelFromAny(
 /*
  *----------------------------------------------------------------------
  *
- * UpdateStringOfChannel --
- *
- *	Update the string representation for an object whose internal
- *	representation is "Channel".
- *
- * Results:
- *	None.
- *
- * Side effects:
- *	The object's string may be set by converting its Unicode represention
- *	to UTF format.
- *
- *----------------------------------------------------------------------
- */
-
-static void
-UpdateStringOfChannel(
-    Tcl_Obj *objPtr)		/* Object with string rep to update. */
-{
-    if (objPtr->bytes == NULL) {
-	ChannelState *statePtr = GET_CHANNELSTATE(objPtr);
-	const char *name = statePtr->channelName;
-
-	if (name) {
-	    size_t len = strlen(name);
-
-	    objPtr->bytes = ckalloc(len + 1);
-	    objPtr->length = len;
-	    memcpy(objPtr->bytes, name, len);
-	} else {
-	    objPtr->bytes = tclEmptyStringRep;
-	    objPtr->length = 0;
-	}
-    }
-}
-
-/*
- *----------------------------------------------------------------------
- *
  * FreeChannelIntRep --
  *
  *	Release statePtr storage.
diff --git a/generic/tclIOUtil.c b/generic/tclIOUtil.c
index 6259216..f624cb7 100644
--- a/generic/tclIOUtil.c
+++ b/generic/tclIOUtil.c
@@ -19,7 +19,7 @@
  */
 
 #include "tclInt.h"
-#ifdef __WIN32__
+#ifdef _WIN32
 #   include "tclWinInt.h"
 #endif
 #include "tclFileSystem.h"
@@ -792,7 +792,7 @@ TclFinalizeFilesystem(void)
      * filesystem is likely to fail.
      */
 
-#ifdef __WIN32__
+#ifdef _WIN32
     TclWinEncodingsCleanup();
 #endif
 }
@@ -819,7 +819,7 @@ TclResetFilesystem(void)
     filesystemList = &nativeFilesystemRecord;
     theFilesystemEpoch++;
 
-#ifdef __WIN32__
+#ifdef _WIN32
     /*
      * Cleans up the win32 API filesystem proc lookup table. This must happen
      * very late in finalization so that deleting of copied dlls can occur.
@@ -3255,7 +3255,7 @@ Tcl_LoadFile(
 	return TCL_ERROR;
     }
 
-#ifndef __WIN32__
+#ifndef _WIN32
     /*
      * Do we need to set appropriate permissions on the file? This may be
      * required on some systems. On Unix we could loop over the file
diff --git a/generic/tclInt.decls b/generic/tclInt.decls
index f0e907f..9f7b106 100644
--- a/generic/tclInt.decls
+++ b/generic/tclInt.decls
@@ -1006,6 +1006,12 @@ declare 249 {
 declare 250 {
     void TclSetSlaveCancelFlags(Tcl_Interp *interp, int flags, int force)
 }
+
+# Allow extensions for optimization
+declare 251 {
+    int TclRegisterLiteral(void *envPtr,
+	    char *bytes, int length, int flags)
+}
 
 ##############################################################################
 
diff --git a/generic/tclInt.h b/generic/tclInt.h
index 5c8dbfd..2aa1725 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -1686,6 +1686,7 @@ typedef struct Command {
 #define CMD_TRACE_ACTIVE	    0x2
 #define CMD_HAS_EXEC_TRACES	    0x4
 #define CMD_COMPILES_EXPANDED	    0x8
+#define CMD_REDEF_IN_PROGRESS	    0x10
 
 /*
  *----------------------------------------------------------------
@@ -1809,7 +1810,14 @@ typedef struct Interp {
     ClientData interpInfo;	/* Information used by tclInterp.c to keep
 				 * track of master/slave interps on a
 				 * per-interp basis. */
-    Tcl_HashTable unused2;	/* No longer used (was mathFuncTable) */
+    union {
+	void (*optimizer)(void *envPtr);
+	Tcl_HashTable unused2;	/* No longer used (was mathFuncTable). The
+				 * unused space in interp was repurposed for
+				 * pluggable bytecode optimizers. The core
+				 * contains one optimizer, which can be
+				 * selectively overriden by extensions. */
+    } extra;
 
     /*
      * Information related to procedures and variables. See tclProc.c and
@@ -2632,6 +2640,8 @@ MODULE_SCOPE char *tclMemDumpFileName;
 MODULE_SCOPE TclPlatformType tclPlatform;
 MODULE_SCOPE Tcl_NotifierProcs tclNotifierHooks;
 
+MODULE_SCOPE Tcl_Encoding tclIdentityEncoding;
+
 /*
  * TIP #233 (Virtualized Time)
  * Data for the time hooks, if any.
@@ -3435,6 +3445,9 @@ MODULE_SCOPE int	TclCompileBreakCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileCatchCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileConcatCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileContinueCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
@@ -3534,6 +3547,9 @@ MODULE_SCOPE int	TclCompileLassignCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileLindexCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileLinsertCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileListCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
@@ -3558,6 +3574,9 @@ MODULE_SCOPE int	TclCompileNamespaceCodeCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileNamespaceCurrentCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileNamespaceOriginCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileNamespaceQualifiersCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
@@ -3573,6 +3592,12 @@ MODULE_SCOPE int	TclCompileNamespaceWhichCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileNoOp(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileObjectNextCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileObjectNextToCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileObjectSelfCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
@@ -3600,6 +3625,9 @@ MODULE_SCOPE int	TclCompileStringFirstCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileStringIndexCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileStringIsCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileStringLastCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
@@ -3615,6 +3643,27 @@ MODULE_SCOPE int	TclCompileStringMatchCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileStringRangeCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileStringReplaceCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileStringToLowerCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileStringToTitleCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileStringToUpperCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileStringTrimCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileStringTrimLCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileStringTrimRCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileSubstCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
@@ -3645,6 +3694,9 @@ MODULE_SCOPE int	TclCompileWhileCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileYieldCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileYieldToCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileBasic0ArgCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
diff --git a/generic/tclIntDecls.h b/generic/tclIntDecls.h
index 47c6afd..f95f999 100644
--- a/generic/tclIntDecls.h
+++ b/generic/tclIntDecls.h
@@ -614,6 +614,9 @@ EXTERN char *		TclDoubleDigits(double dv, int ndigits, int flags,
 /* 250 */
 EXTERN void		TclSetSlaveCancelFlags(Tcl_Interp *interp, int flags,
 				int force);
+/* 251 */
+EXTERN int		TclRegisterLiteral(void *envPtr, char *bytes,
+				int length, int flags);
 
 typedef struct TclIntStubs {
     int magic;
@@ -870,6 +873,7 @@ typedef struct TclIntStubs {
     int (*tclCopyChannel) (Tcl_Interp *interp, Tcl_Channel inChan, Tcl_Channel outChan, Tcl_WideInt toRead, Tcl_Obj *cmdPtr); /* 248 */
     char * (*tclDoubleDigits) (double dv, int ndigits, int flags, int *decpt, int *signum, char **endPtr); /* 249 */
     void (*tclSetSlaveCancelFlags) (Tcl_Interp *interp, int flags, int force); /* 250 */
+    int (*tclRegisterLiteral) (void *envPtr, char *bytes, int length, int flags); /* 251 */
 } TclIntStubs;
 
 extern const TclIntStubs *tclIntStubsPtr;
@@ -1299,6 +1303,8 @@ extern const TclIntStubs *tclIntStubsPtr;
 	(tclIntStubsPtr->tclDoubleDigits) /* 249 */
 #define TclSetSlaveCancelFlags \
 	(tclIntStubsPtr->tclSetSlaveCancelFlags) /* 250 */
+#define TclRegisterLiteral \
+	(tclIntStubsPtr->tclRegisterLiteral) /* 251 */
 
 #endif /* defined(USE_TCL_STUBS) */
 
diff --git a/generic/tclIntPlatDecls.h b/generic/tclIntPlatDecls.h
index 72719fe..2c74b5a 100644
--- a/generic/tclIntPlatDecls.h
+++ b/generic/tclIntPlatDecls.h
@@ -13,7 +13,7 @@
 #ifndef _TCLINTPLATDECLS
 #define _TCLINTPLATDECLS
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #   define Tcl_DirEntry void
 #   define DIR void
 #endif
@@ -45,7 +45,7 @@ extern "C" {
  * Exported function declarations:
  */
 
-#if !defined(__WIN32__) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
 /* 0 */
 EXTERN void		TclGetAndDetachPids(Tcl_Interp *interp,
 				Tcl_Channel chan);
@@ -104,7 +104,7 @@ EXTERN int		TclUnixOpenTemporaryFile(Tcl_Obj *dirObj,
 				Tcl_Obj *basenameObj, Tcl_Obj *extensionObj,
 				Tcl_Obj *resultingNameObj);
 #endif /* UNIX */
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 /* 0 */
 EXTERN void		TclWinConvertError(DWORD errCode);
 /* 1 */
@@ -258,7 +258,7 @@ typedef struct TclIntPlatStubs {
     int magic;
     void *hooks;
 
-#if !defined(__WIN32__) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
     void (*tclGetAndDetachPids) (Tcl_Interp *interp, Tcl_Channel chan); /* 0 */
     int (*tclpCloseFile) (TclFile file); /* 1 */
     Tcl_Channel (*tclpCreateCommandChannel) (TclFile readFile, TclFile writeFile, TclFile errorFile, int numPids, Tcl_Pid *pidPtr); /* 2 */
@@ -291,7 +291,7 @@ typedef struct TclIntPlatStubs {
     int (*tclWinCPUID) (unsigned int index, unsigned int *regs); /* 29 */
     int (*tclUnixOpenTemporaryFile) (Tcl_Obj *dirObj, Tcl_Obj *basenameObj, Tcl_Obj *extensionObj, Tcl_Obj *resultingNameObj); /* 30 */
 #endif /* UNIX */
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
     void (*tclWinConvertError) (DWORD errCode); /* 0 */
     void (*tclWinConvertWSAError) (DWORD errCode); /* 1 */
     struct servent * (*tclWinGetServByName) (const char *nm, const char *proto); /* 2 */
@@ -371,7 +371,7 @@ extern const TclIntPlatStubs *tclIntPlatStubsPtr;
  * Inline function declarations:
  */
 
-#if !defined(__WIN32__) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
 #define TclGetAndDetachPids \
 	(tclIntPlatStubsPtr->tclGetAndDetachPids) /* 0 */
 #define TclpCloseFile \
@@ -420,7 +420,7 @@ extern const TclIntPlatStubs *tclIntPlatStubsPtr;
 #define TclUnixOpenTemporaryFile \
 	(tclIntPlatStubsPtr->tclUnixOpenTemporaryFile) /* 30 */
 #endif /* UNIX */
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 #define TclWinConvertError \
 	(tclIntPlatStubsPtr->tclWinConvertError) /* 0 */
 #define TclWinConvertWSAError \
@@ -550,7 +550,7 @@ extern const TclIntPlatStubs *tclIntPlatStubsPtr;
 #undef TclpInetNtoa
 #define TclpInetNtoa inet_ntoa
 
-#if defined(__WIN32__) || defined(__CYGWIN__)
+#if defined(_WIN32) || defined(__CYGWIN__)
 #   undef TclWinNToHS
 #   define TclWinNToHS ntohs
 #else
diff --git a/generic/tclLiteral.c b/generic/tclLiteral.c
index 11da6f8..2b0cc7e 100644
--- a/generic/tclLiteral.c
+++ b/generic/tclLiteral.c
@@ -358,7 +358,7 @@ TclFetchLiteral(
 
 int
 TclRegisterLiteral(
-    CompileEnv *envPtr,		/* Points to the CompileEnv in whose object
+    void *ePtr,		/* Points to the CompileEnv in whose object
 				 * array an object is found or created. */
     register char *bytes,	/* Points to string for which to find or
 				 * create an object in CompileEnv's object
@@ -372,6 +372,7 @@ TclRegisterLiteral(
 				 * the literal should not be shared accross
 				 * namespaces. */
 {
+    CompileEnv *envPtr = ePtr;
     Interp *iPtr = envPtr->iPtr;
     LiteralTable *localTablePtr = &envPtr->localLitTable;
     LiteralEntry *globalPtr, *localPtr;
diff --git a/generic/tclLoad.c b/generic/tclLoad.c
index 5cacab1..7c70e03 100644
--- a/generic/tclLoad.c
+++ b/generic/tclLoad.c
@@ -830,7 +830,7 @@ Tcl_UnloadObjCmd(
 	 * Unload the shared library from the application memory...
 	 */
 
-#if defined(TCL_UNLOAD_DLLS) || defined(__WIN32__)
+#if defined(TCL_UNLOAD_DLLS) || defined(_WIN32)
 	/*
 	 * Some Unix dlls are poorly behaved - registering things like atexit
 	 * calls that can't be unregistered. If you unload such dlls, you get
@@ -1151,7 +1151,7 @@ TclFinalizeLoad(void)
 	pkgPtr = firstPackagePtr;
 	firstPackagePtr = pkgPtr->nextPtr;
 
-#if defined(TCL_UNLOAD_DLLS) || defined(__WIN32__)
+#if defined(TCL_UNLOAD_DLLS) || defined(_WIN32)
 	/*
 	 * Some Unix dlls are poorly behaved - registering things like atexit
 	 * calls that can't be unregistered. If you unload such dlls, you get
diff --git a/generic/tclMain.c b/generic/tclMain.c
index faea75a..360f5e9 100644
--- a/generic/tclMain.c
+++ b/generic/tclMain.c
@@ -47,7 +47,7 @@
  * we have to translate that to strcmp here.
  */
 
-#ifndef __WIN32__
+#ifndef _WIN32
 #   define TCHAR char
 #   define TEXT(arg) arg
 #   define _tcscmp strcmp
diff --git a/generic/tclNamesp.c b/generic/tclNamesp.c
index cd44455..8f2f10e 100644
--- a/generic/tclNamesp.c
+++ b/generic/tclNamesp.c
@@ -171,7 +171,7 @@ static const EnsembleImplMap defaultNamespaceMap[] = {
     {"forget",	   NamespaceForgetCmd,	TclCompileBasicMin0ArgCmd, NULL, NULL, 0},
     {"import",	   NamespaceImportCmd,	TclCompileBasicMin0ArgCmd, NULL, NULL, 0},
     {"inscope",	   NamespaceInscopeCmd,	NULL, NRNamespaceInscopeCmd, NULL, 0},
-    {"origin",	   NamespaceOriginCmd,	TclCompileBasic1ArgCmd, NULL, NULL, 0},
+    {"origin",	   NamespaceOriginCmd,	TclCompileNamespaceOriginCmd, NULL, NULL, 0},
     {"parent",	   NamespaceParentCmd,	TclCompileBasic0Or1ArgCmd, NULL, NULL, 0},
     {"path",	   NamespacePathCmd,	TclCompileBasic0Or1ArgCmd, NULL, NULL, 0},
     {"qualifiers", NamespaceQualifiersCmd, TclCompileNamespaceQualifiersCmd, NULL, NULL, 0},
diff --git a/generic/tclOO.c b/generic/tclOO.c
index 529640f..de00733 100644
--- a/generic/tclOO.c
+++ b/generic/tclOO.c
@@ -437,10 +437,12 @@ InitFoundation(
      * ensemble.
      */
 
-    Tcl_CreateObjCommand(interp, "::oo::Helpers::next", TclOONextObjCmd, NULL,
-	    NULL);
-    Tcl_CreateObjCommand(interp, "::oo::Helpers::nextto", TclOONextToObjCmd,
-	    NULL, NULL);
+    cmdPtr = (Command *) Tcl_NRCreateCommand(interp, "::oo::Helpers::next",
+	    NULL, TclOONextObjCmd, NULL, NULL);
+    cmdPtr->compileProc = TclCompileObjectNextCmd;
+    cmdPtr = (Command *) Tcl_NRCreateCommand(interp, "::oo::Helpers::nextto",
+	    NULL, TclOONextToObjCmd, NULL, NULL);
+    cmdPtr->compileProc = TclCompileObjectNextToCmd;
     cmdPtr = (Command *) Tcl_CreateObjCommand(interp, "::oo::Helpers::self",
 	    TclOOSelfObjCmd, NULL, NULL);
     cmdPtr->compileProc = TclCompileObjectSelfCmd;
diff --git a/generic/tclOOBasic.c b/generic/tclOOBasic.c
index 853e2ec..0b0516b 100644
--- a/generic/tclOOBasic.c
+++ b/generic/tclOOBasic.c
@@ -17,16 +17,11 @@
 #include "tclOOInt.h"
 
 static inline Tcl_Object *AddConstructionFinalizer(Tcl_Interp *interp);
-static int		AfterNRDestructor(ClientData data[],
-			    Tcl_Interp *interp, int result);
-static int		DecrRefsPostClassConstructor(ClientData data[],
-			    Tcl_Interp *interp, int result);
-static int		FinalizeConstruction(ClientData data[],
-			    Tcl_Interp *interp, int result);
-static int		FinalizeEval(ClientData data[],
-			    Tcl_Interp *interp, int result);
-static int		RestoreFrame(ClientData data[],
-			    Tcl_Interp *interp, int result);
+static Tcl_NRPostProc	AfterNRDestructor;
+static Tcl_NRPostProc	DecrRefsPostClassConstructor;
+static Tcl_NRPostProc	FinalizeConstruction;
+static Tcl_NRPostProc	FinalizeEval;
+static Tcl_NRPostProc	NextRestoreFrame;
 
 /*
  * ----------------------------------------------------------------------
@@ -808,7 +803,7 @@ TclOONextObjCmd(
      * that this is like [uplevel 1] and not [eval].
      */
 
-    TclNRAddCallback(interp, RestoreFrame, framePtr, NULL, NULL, NULL);
+    TclNRAddCallback(interp, NextRestoreFrame, framePtr, NULL,NULL,NULL);
     iPtr->varFramePtr = framePtr->callerVarPtr;
     return TclNRObjectContextInvokeNext(interp, context, objc, objv, 1);
 }
@@ -826,6 +821,7 @@ TclOONextToObjCmd(
     CallContext *contextPtr;
     int i;
     Tcl_Object object;
+    const char *methodType;
 
     /*
      * Start with sanity checks on the calling context to make sure that we
@@ -877,8 +873,8 @@ TclOONextToObjCmd(
 	     * context. Note that this is like [uplevel 1] and not [eval].
 	     */
 
-	    TclNRAddCallback(interp, RestoreFrame, framePtr, contextPtr,
-		    INT2PTR(contextPtr->index), NULL);
+	    TclNRAddCallback(interp, NextRestoreFrame, framePtr,
+		    contextPtr, INT2PTR(contextPtr->index), NULL);
 	    contextPtr->index = i-1;
 	    iPtr->varFramePtr = framePtr->callerVarPtr;
 	    return TclNRObjectContextInvokeNext(interp,
@@ -891,24 +887,35 @@ TclOONextToObjCmd(
      * is on the chain but unreachable, or not on the chain at all.
      */
 
+    if (contextPtr->callPtr->flags & CONSTRUCTOR) {
+	methodType = "constructor";
+    } else if (contextPtr->callPtr->flags & DESTRUCTOR) {
+	methodType = "destructor";
+    } else {
+	methodType = "method";
+    }
+
     for (i=contextPtr->index ; i>=0 ; i--) {
 	struct MInvoke *miPtr = contextPtr->callPtr->chain + i;
 
 	if (!miPtr->isFilter && miPtr->mPtr->declaringClassPtr == classPtr) {
 	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
-		    "method implementation by \"%s\" not reachable from here",
-		    TclGetString(objv[1])));
+		    "%s implementation by \"%s\" not reachable from here",
+		    methodType, TclGetString(objv[1])));
+	    Tcl_SetErrorCode(interp, "TCL", "OO", "CLASS_NOT_REACHABLE",
+		    NULL);
 	    return TCL_ERROR;
 	}
     }
     Tcl_SetObjResult(interp, Tcl_ObjPrintf(
-	    "method has no non-filter implementation by \"%s\"",
-	    TclGetString(objv[1])));
+	    "%s has no non-filter implementation by \"%s\"",
+	    methodType, TclGetString(objv[1])));
+    Tcl_SetErrorCode(interp, "TCL", "OO", "CLASS_NOT_THERE", NULL);
     return TCL_ERROR;
 }
 
 static int
-RestoreFrame(
+NextRestoreFrame(
     ClientData data[],
     Tcl_Interp *interp,
     int result)
diff --git a/generic/tclOptimize.c b/generic/tclOptimize.c
index 3b16e6e..827d89d 100644
--- a/generic/tclOptimize.c
+++ b/generic/tclOptimize.c
@@ -191,7 +191,7 @@ TrimUnreachable(
  * ConvertZeroEffectToNOP --
  *
  *	Replace PUSH/POP sequences (when non-hazardous) with NOPs. Also
- *	replace PUSH empty/CONCAT and TRY_CVT_NUMERIC (when followed by an
+ *	replace PUSH empty/STR_CONCAT and TRY_CVT_NUMERIC (when followed by an
  *	operation that guarantees the check for arithmeticity) and eliminate
  *	LNOT when we can invert the following JUMP condition.
  *
@@ -227,7 +227,7 @@ ConvertZeroEffectToNOP(
 	case INST_PUSH1:
 	    if (nextInst == INST_POP) {
 		blank = size + InstLength(nextInst);
-	    } else if (nextInst == INST_CONCAT1
+	    } else if (nextInst == INST_STR_CONCAT1
 		    && TclGetUInt1AtPtr(currentInstPtr + size + 1) == 2) {
 		Tcl_Obj *litPtr = TclFetchLiteral(envPtr,
 			TclGetUInt1AtPtr(currentInstPtr + 1));
@@ -242,7 +242,7 @@ ConvertZeroEffectToNOP(
 	case INST_PUSH4:
 	    if (nextInst == INST_POP) {
 		blank = size + 1;
-	    } else if (nextInst == INST_CONCAT1
+	    } else if (nextInst == INST_STR_CONCAT1
 		    && TclGetUInt1AtPtr(currentInstPtr + size + 1) == 2) {
 		Tcl_Obj *litPtr = TclFetchLiteral(envPtr,
 			TclGetUInt4AtPtr(currentInstPtr + 1));
@@ -427,7 +427,7 @@ AdvanceJumps(
 
 void
 TclOptimizeBytecode(
-    CompileEnv *envPtr)
+    void *envPtr)
 {
     ConvertZeroEffectToNOP(envPtr);
     AdvanceJumps(envPtr);
diff --git a/generic/tclPathObj.c b/generic/tclPathObj.c
index b7f3dcf..fe6063f 100644
--- a/generic/tclPathObj.c
+++ b/generic/tclPathObj.c
@@ -512,7 +512,7 @@ TclFSGetPathType(
 
     if (PATHFLAGS(pathPtr) == 0) {
 	/* The path is not absolute... */
-#ifdef __WIN32__
+#ifdef _WIN32
 	/* ... on Windows we must make another call to determine whether
 	 * it's relative or volumerelative [Bug 2571597]. */
 	return TclGetPathType(pathPtr, filesystemPtrPtr, driveNameLengthPtr,
@@ -1956,7 +1956,7 @@ Tcl_FSGetNormalizedPath(
 		/*
 		 * We have a refCount on the cwd.
 		 */
-#ifdef __WIN32__
+#ifdef _WIN32
 	    } else if (type == TCL_PATH_VOLUME_RELATIVE) {
 		/*
 		 * Only Windows has volume-relative paths.
@@ -1969,7 +1969,7 @@ Tcl_FSGetNormalizedPath(
 		    return NULL;
 		}
 		pureNormalized = 0;
-#endif /* __WIN32__ */
+#endif /* _WIN32 */
 	    }
 	}
 
diff --git a/generic/tclPlatDecls.h b/generic/tclPlatDecls.h
index 681854d..abc8ee8 100644
--- a/generic/tclPlatDecls.h
+++ b/generic/tclPlatDecls.h
@@ -50,7 +50,7 @@ extern "C" {
  * Exported function declarations:
  */
 
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 /* 0 */
 EXTERN TCHAR *		Tcl_WinUtfToTChar(const char *str, int len,
 				Tcl_DString *dsPtr);
@@ -75,7 +75,7 @@ typedef struct TclPlatStubs {
     int magic;
     void *hooks;
 
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
     TCHAR * (*tcl_WinUtfToTChar) (const char *str, int len, Tcl_DString *dsPtr); /* 0 */
     char * (*tcl_WinTCharToUtf) (const TCHAR *str, int len, Tcl_DString *dsPtr); /* 1 */
 #endif /* WIN */
@@ -97,7 +97,7 @@ extern const TclPlatStubs *tclPlatStubsPtr;
  * Inline function declarations:
  */
 
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 #define Tcl_WinUtfToTChar \
 	(tclPlatStubsPtr->tcl_WinUtfToTChar) /* 0 */
 #define Tcl_WinTCharToUtf \
diff --git a/generic/tclProc.c b/generic/tclProc.c
index 1314719..ce1c767 100644
--- a/generic/tclProc.c
+++ b/generic/tclProc.c
@@ -1855,9 +1855,39 @@ InterpProcNR2(
     }
 
     /*
-     * Process the result code.
+     * Free the stack-allocated compiled locals and CallFrame. It is important
+     * to pop the call frame without freeing it first: the compiledLocals
+     * cannot be freed before the frame is popped, as the local variables must
+     * be deleted. But the compiledLocals must be freed first, as they were
+     * allocated later on the stack.
      */
 
+    if (result != TCL_OK) {
+	goto process;
+    }
+    
+    done: 
+    if (TCL_DTRACE_PROC_RESULT_ENABLED()) {
+	int l = iPtr->varFramePtr->isProcCallFrame & FRAME_IS_LAMBDA ? 1 : 0;
+	Tcl_Obj *r = Tcl_GetObjResult(interp);
+
+	TCL_DTRACE_PROC_RESULT(l < iPtr->varFramePtr->objc ?
+		TclGetString(iPtr->varFramePtr->objv[l]) : NULL, result,
+		TclGetString(r), r);
+    }
+
+    freePtr = iPtr->framePtr;
+    Tcl_PopCallFrame(interp);		/* Pop but do not free. */
+    TclStackFree(interp, freePtr->compiledLocals);
+					/* Free compiledLocals. */
+    TclStackFree(interp, freePtr);	/* Free CallFrame. */
+    return result;
+
+    /*
+     * Process any non-TCL_OK result code.
+     */
+
+    process:
     switch (result) {
     case TCL_RETURN:
 	/*
@@ -1892,46 +1922,8 @@ InterpProcNR2(
 	 */
 
 	errorProc(interp, procNameObj);
-
-    default:
-	/*
-	 * Process other results (OK and non-standard) by doing nothing
-	 * special, skipping directly to the code afterwards that cleans up
-	 * associated memory.
-	 *
-	 * Non-standard results are processed by passing them through quickly.
-	 * This means they all work as exceptions, unwinding the stack quickly
-	 * and neatly. Who knows how well they are handled by third-party code
-	 * though...
-	 */
-
-	(void) 0;		/* do nothing */
-    }
-
-    if (TCL_DTRACE_PROC_RESULT_ENABLED()) {
-	int l = iPtr->varFramePtr->isProcCallFrame & FRAME_IS_LAMBDA ? 1 : 0;
-	Tcl_Obj *r = Tcl_GetObjResult(interp);
-
-	TCL_DTRACE_PROC_RESULT(l < iPtr->varFramePtr->objc ?
-		TclGetString(iPtr->varFramePtr->objv[l]) : NULL, result,
-		TclGetString(r), r);
     }
-
-    /*
-     * Free the stack-allocated compiled locals and CallFrame. It is important
-     * to pop the call frame without freeing it first: the compiledLocals
-     * cannot be freed before the frame is popped, as the local variables must
-     * be deleted. But the compiledLocals must be freed first, as they were
-     * allocated later on the stack.
-     */
-
-    freePtr = iPtr->framePtr;
-    Tcl_PopCallFrame(interp);		/* Pop but do not free. */
-    TclStackFree(interp, freePtr->compiledLocals);
-					/* Free compiledLocals. */
-    TclStackFree(interp, freePtr);	/* Free CallFrame. */
-
-    return result;
+    goto done;
 }
 
 /*
diff --git a/generic/tclStringObj.c b/generic/tclStringObj.c
index e495c2e..dffa38c 100644
--- a/generic/tclStringObj.c
+++ b/generic/tclStringObj.c
@@ -1281,23 +1281,43 @@ Tcl_AppendObjToObj(
 
     if ((TclIsPureByteArray(objPtr) || objPtr->bytes == tclEmptyStringRep)
 	    && TclIsPureByteArray(appendObjPtr)) {
-	unsigned char *bytesSrc;
-	int lengthSrc, lengthTotal;
 
 	/*
-	 * We do not assume that objPtr and appendObjPtr must be distinct!
-	 * This makes this code a bit more complex than it otherwise would be,
-	 * but in turn makes it much safer.
+	 * You might expect the code here to be
+	 *
+	 *  bytes = Tcl_GetByteArrayFromObj(appendObjPtr, &length);
+	 *  TclAppendBytesToByteArray(objPtr, bytes, length);
+	 *
+	 * and essentially all of the time that would be fine.  However,
+	 * it would run into trouble in the case where objPtr and
+	 * appendObjPtr point to the same thing.  That may never be a
+	 * good idea.  It seems to violate Copy On Write, and we don't
+	 * have any tests for the situation, since making any Tcl commands
+	 * that call Tcl_AppendObjToObj() do that appears impossible
+	 * (They honor Copy On Write!).  For the sake of extensions that
+	 * go off into that realm, though, here's a more complex approach
+	 * that can handle all the cases.
 	 */
 
+	/* Get lengths */
+	int lengthSrc;
+
 	(void) Tcl_GetByteArrayFromObj(objPtr, &length);
 	(void) Tcl_GetByteArrayFromObj(appendObjPtr, &lengthSrc);
-	lengthTotal = length + lengthSrc;
-	if (((length > lengthSrc) ? length : lengthSrc) > lengthTotal) {
-	    Tcl_Panic("max size for a Tcl value (%d bytes) exceeded", INT_MAX);
-	}
-	bytesSrc = Tcl_GetByteArrayFromObj(appendObjPtr, NULL);
-	TclAppendBytesToByteArray(objPtr, bytesSrc, lengthSrc);
+
+	/* Grow buffer enough for the append */
+	TclAppendBytesToByteArray(objPtr, NULL, lengthSrc);
+
+	/* Reset objPtr back to the original value */
+	Tcl_SetByteArrayLength(objPtr, length);
+
+	/*
+	 * Now do the append knowing that buffer growth cannot cause
+	 * any trouble.
+	 */
+
+	TclAppendBytesToByteArray(objPtr,
+		Tcl_GetByteArrayFromObj(appendObjPtr, NULL), lengthSrc);
 	return;
     }
 
diff --git a/generic/tclStringTrim.h b/generic/tclStringTrim.h
new file mode 100644
index 0000000..030e4ec
--- /dev/null
+++ b/generic/tclStringTrim.h
@@ -0,0 +1,43 @@
+/*
+ * tclStringTrim.h --
+ *
+ *	This file contains the definition of what characters are to be trimmed
+ *	from a string by [string trim] by default. It's only needed by Tcl's
+ *	implementation; it does not form a public or private API at all.
+ *
+ * Copyright (c) 1987-1993 The Regents of the University of California.
+ * Copyright (c) 1994-1997 Sun Microsystems, Inc.
+ * Copyright (c) 1998-2000 Scriptics Corporation.
+ * Copyright (c) 2002 ActiveState Corporation.
+ * Copyright (c) 2003-2013 Donal K. Fellows.
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ */
+
+#ifndef TCL_STRING_TRIM_H
+#define TCL_STRING_TRIM_H
+
+/*
+ * Default set of characters to trim in [string trim] and friends. This is a
+ * UTF-8 literal string containing all Unicode space characters. [TIP #413]
+ */
+
+MODULE_SCOPE const char tclDefaultTrimSet[];
+
+/*
+ * The whitespace trimming set used when [concat]enating. This is a subset of
+ * the above, and deliberately so.
+ */
+
+#define CONCAT_TRIM_SET " \f\v\r\t\n"
+
+#endif /* TCL_STRING_TRIM_H */
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */
diff --git a/generic/tclStubInit.c b/generic/tclStubInit.c
index 3f1c27b..097269f 100644
--- a/generic/tclStubInit.c
+++ b/generic/tclStubInit.c
@@ -90,7 +90,7 @@ static unsigned short TclWinNToHS(unsigned short ns) {
 }
 #endif
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #   define TclUnixWaitForFile 0
 #   define TclUnixCopyFile 0
 #   define TclUnixOpenTemporaryFile 0
@@ -551,12 +551,13 @@ static const TclIntStubs tclIntStubs = {
     TclCopyChannel, /* 248 */
     TclDoubleDigits, /* 249 */
     TclSetSlaveCancelFlags, /* 250 */
+    TclRegisterLiteral, /* 251 */
 };
 
 static const TclIntPlatStubs tclIntPlatStubs = {
     TCL_STUB_MAGIC,
     0,
-#if !defined(__WIN32__) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
     TclGetAndDetachPids, /* 0 */
     TclpCloseFile, /* 1 */
     TclpCreateCommandChannel, /* 2 */
@@ -589,7 +590,7 @@ static const TclIntPlatStubs tclIntPlatStubs = {
     TclWinCPUID, /* 29 */
     TclUnixOpenTemporaryFile, /* 30 */
 #endif /* UNIX */
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
     TclWinConvertError, /* 0 */
     TclWinConvertWSAError, /* 1 */
     TclWinGetServByName, /* 2 */
@@ -660,7 +661,7 @@ static const TclIntPlatStubs tclIntPlatStubs = {
 static const TclPlatStubs tclPlatStubs = {
     TCL_STUB_MAGIC,
     0,
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
     Tcl_WinUtfToTChar, /* 0 */
     Tcl_WinTCharToUtf, /* 1 */
 #endif /* WIN */
@@ -757,19 +758,19 @@ const TclStubs tclStubs = {
     Tcl_DbCkalloc, /* 6 */
     Tcl_DbCkfree, /* 7 */
     Tcl_DbCkrealloc, /* 8 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     Tcl_CreateFileHandler, /* 9 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     0, /* 9 */
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
     Tcl_CreateFileHandler, /* 9 */
 #endif /* MACOSX */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     Tcl_DeleteFileHandler, /* 10 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     0, /* 10 */
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
@@ -931,10 +932,10 @@ const TclStubs tclStubs = {
     Tcl_GetMaster, /* 164 */
     Tcl_GetNameOfExecutable, /* 165 */
     Tcl_GetObjResult, /* 166 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     Tcl_GetOpenFile, /* 167 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     0, /* 167 */
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
diff --git a/generic/tclTest.c b/generic/tclTest.c
index f121d0d..a27c95a 100644
--- a/generic/tclTest.c
+++ b/generic/tclTest.c
@@ -414,7 +414,7 @@ static int		TestNRELevels(ClientData clientData,
 static int		TestInterpResolverCmd(ClientData clientData,
 			    Tcl_Interp *interp, int objc,
 			    Tcl_Obj *const objv[]);
-#if defined(HAVE_CPUID) || defined(__WIN32__)
+#if defined(HAVE_CPUID) || defined(_WIN32)
 static int		TestcpuidCmd(ClientData dummy,
 			    Tcl_Interp* interp, int objc,
 			    Tcl_Obj *const objv[]);
@@ -681,7 +681,7 @@ Tcltest_Init(
 	    NULL, NULL);
     Tcl_CreateCommand(interp, "testexitmainloop", TestexitmainloopCmd,
 	    NULL, NULL);
-#if defined(HAVE_CPUID) || defined(__WIN32__)
+#if defined(HAVE_CPUID) || defined(_WIN32)
     Tcl_CreateObjCommand(interp, "testcpuid", TestcpuidCmd,
 	    (ClientData) 0, NULL);
 #endif
@@ -6648,7 +6648,7 @@ TestNumUtfCharsCmd(
     return TCL_OK;
 }
 
-#if defined(HAVE_CPUID) || defined(__WIN32__)
+#if defined(HAVE_CPUID) || defined(_WIN32)
 /*
  *----------------------------------------------------------------------
  *
diff --git a/generic/tclThreadJoin.c b/generic/tclThreadJoin.c
index 4b09e1c..5c70a62 100644
--- a/generic/tclThreadJoin.c
+++ b/generic/tclThreadJoin.c
@@ -14,7 +14,7 @@
 
 #include "tclInt.h"
 
-#ifdef WIN32
+#ifdef _WIN32
 
 /*
  * The information about each joinable thread is remembered in a structure as
@@ -305,7 +305,7 @@ TclSignalExitThread(
 
     Tcl_MutexUnlock(&threadPtr->threadMutex);
 }
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
 /*
  * Local Variables:
diff --git a/generic/tclUtil.c b/generic/tclUtil.c
index b089132..2d00adf 100644
--- a/generic/tclUtil.c
+++ b/generic/tclUtil.c
@@ -14,6 +14,7 @@
 
 #include "tclInt.h"
 #include "tclParse.h"
+#include "tclStringTrim.h"
 #include <math.h>
 
 /*
@@ -1768,8 +1769,7 @@ TclTrimLeft(
  */
 
 /* The whitespace characters trimmed during [concat] operations */
-#define CONCAT_WS " \f\v\r\t\n"
-#define CONCAT_WS_SIZE (int) (sizeof(CONCAT_WS "") - 1)
+#define CONCAT_WS_SIZE (int) (sizeof(CONCAT_TRIM_SET "") - 1)
 
 char *
 Tcl_Concat(
@@ -1825,7 +1825,8 @@ Tcl_Concat(
 	 * Trim away the leading whitespace.
 	 */
 
-	trim = TclTrimLeft(element, elemLength, CONCAT_WS, CONCAT_WS_SIZE);
+	trim = TclTrimLeft(element, elemLength, CONCAT_TRIM_SET,
+		CONCAT_WS_SIZE);
 	element += trim;
 	elemLength -= trim;
 
@@ -1834,7 +1835,8 @@ Tcl_Concat(
 	 * a final backslash character.
 	 */
 
-	trim = TclTrimRight(element, elemLength, CONCAT_WS, CONCAT_WS_SIZE);
+	trim = TclTrimRight(element, elemLength, CONCAT_TRIM_SET,
+		CONCAT_WS_SIZE);
 	trim -= trim && (element[elemLength - trim - 1] == '\\');
 	elemLength -= trim;
 
@@ -1959,7 +1961,8 @@ Tcl_ConcatObj(
 	 * Trim away the leading whitespace.
 	 */
 
-	trim = TclTrimLeft(element, elemLength, CONCAT_WS, CONCAT_WS_SIZE);
+	trim = TclTrimLeft(element, elemLength, CONCAT_TRIM_SET,
+		CONCAT_WS_SIZE);
 	element += trim;
 	elemLength -= trim;
 
@@ -1968,7 +1971,8 @@ Tcl_ConcatObj(
 	 * a final backslash character.
 	 */
 
-	trim = TclTrimRight(element, elemLength, CONCAT_WS, CONCAT_WS_SIZE);
+	trim = TclTrimRight(element, elemLength, CONCAT_TRIM_SET,
+		CONCAT_WS_SIZE);
 	trim -= trim && (element[elemLength - trim - 1] == '\\');
 	elemLength -= trim;
 
diff --git a/library/init.tcl b/library/init.tcl
index 1ca6413..f63eedf 100644
--- a/library/init.tcl
+++ b/library/init.tcl
@@ -130,9 +130,9 @@ if {(![interp issafe]) && ($tcl_platform(platform) eq "windows")} {
 		    switch -- $u {
 			COMSPEC -
 			PATH {
-			    if {![info exists env($u)]} {
-				set env($u) $env($p)
-			    }
+			    set temp $env($p)
+			    unset env($p)
+			    set env($u) $temp
 			    trace add variable env($p) write \
 				    [namespace code [list EnvTraceProc $p]]
 			    trace add variable env($u) write \
@@ -142,11 +142,7 @@ if {(![interp issafe]) && ($tcl_platform(platform) eq "windows")} {
 		}
 	    }
 	    if {![info exists env(COMSPEC)]} {
-		if {$tcl_platform(os) eq "Windows NT"} {
-		    set env(COMSPEC) cmd.exe
-		} else {
-		    set env(COMSPEC) command.com
-		}
+		set env(COMSPEC) cmd.exe
 	    }
 	}
 	InitWinEnv
diff --git a/library/parray.tcl b/library/parray.tcl
index 3ce9817..a9c2cb1 100644
--- a/library/parray.tcl
+++ b/library/parray.tcl
@@ -11,7 +11,7 @@
 proc parray {a {pattern *}} {
     upvar 1 $a array
     if {![array exists array]} {
-	error "\"$a\" isn't an array"
+	return -code error "\"$a\" isn't an array"
     }
     set maxl 0
     set names [lsort [array names array $pattern]]
diff --git a/library/tcltest/pkgIndex.tcl b/library/tcltest/pkgIndex.tcl
index 60a9485..c99ad2a 100644
--- a/library/tcltest/pkgIndex.tcl
+++ b/library/tcltest/pkgIndex.tcl
@@ -9,4 +9,4 @@
 # full path name of this file's directory.
 
 if {![package vsatisfies [package provide Tcl] 8.5]} {return}
-package ifneeded tcltest 2.3.6 [list source [file join $dir tcltest.tcl]]
+package ifneeded tcltest 2.3.7 [list source [file join $dir tcltest.tcl]]
diff --git a/library/tcltest/tcltest.tcl b/library/tcltest/tcltest.tcl
index c30d2e4..4b94312 100644
--- a/library/tcltest/tcltest.tcl
+++ b/library/tcltest/tcltest.tcl
@@ -22,7 +22,7 @@ namespace eval tcltest {
     # When the version number changes, be sure to update the pkgIndex.tcl file,
     # and the install directory in the Makefiles.  When the minor version
     # changes (new feature) be sure to update the man page as well.
-    variable Version 2.3.6
+    variable Version 2.3.7
 
     # Compatibility support for dumb variables defined in tcltest 1
     # Do not use these.  Call [package provide Tcl] and [info patchlevel]
@@ -2498,17 +2498,15 @@ proc tcltest::cleanupTests {{calledFromAllFile 0}} {
 	    if {![info exists originalEnv($index)]} {
 		lappend newEnv $index
 		unset ::env($index)
-	    } else {
-		if {$::env($index) != $originalEnv($index)} {
-		    lappend changedEnv $index
-		    set ::env($index) $originalEnv($index)
-		}
 	    }
 	}
 	foreach index [array names originalEnv] {
 	    if {![info exists ::env($index)]} {
 		lappend removedEnv $index
 		set ::env($index) $originalEnv($index)
+	    } elseif {$::env($index) ne $originalEnv($index)} {
+		lappend changedEnv $index
+		set ::env($index) $originalEnv($index)
 	    }
 	}
 	if {[llength $newEnv] > 0} {
diff --git a/tests/compile.test b/tests/compile.test
index 36e24de..2852bf2 100644
--- a/tests/compile.test
+++ b/tests/compile.test
@@ -167,6 +167,36 @@ test compile-3.6 {TclCompileCatchCmd: error in storing result [Bug 3098302]} {*}
     -cleanup {namespace delete catchtest}
 }
 
+test compile-3.7 {TclCompileCatchCmd: error in storing options [Bug 3098302]} {*}{
+     -setup {
+	 namespace eval catchtest {
+	     variable options1 {}
+	 }
+	 trace add variable catchtest::options1 write catchtest::failtrace
+	 proc catchtest::failtrace {n1 n2 op} {
+	     return -code error "trace on $n1 fails by request"
+	 }
+     }
+    -body {
+	proc catchtest::x {} {
+	    variable options1
+	    set count 0
+	    for {set i 0} {$i < 10} {incr i} {
+		set status2 [catch {
+		    set status1 [catch {
+			return -code error -level 0 "original failure"
+		    } result1 options1]
+		} result2 options2]
+		incr count
+	    }
+	    list $count $result2
+	}
+	catchtest::x
+    }
+    -result {10 {can't set "options1": trace on options1 fails by request}}
+    -cleanup {namespace delete catchtest}
+}
+
 test compile-4.1 {TclCompileForCmd: command substituted test expression} {
     set i 0
     set j 0
diff --git a/tests/coroutine.test b/tests/coroutine.test
index 03c63ad..05b58c9 100644
--- a/tests/coroutine.test
+++ b/tests/coroutine.test
@@ -1,4 +1,4 @@
-# Commands covered:  coroutine, yield, [info coroutine]
+# Commands covered:  coroutine, yield, yieldto, [info coroutine]
 #
 # This file contains a collection of tests for experimental commands that are
 # found in ::tcl::unsupported. The tests will migrate to normal test files
@@ -342,6 +342,9 @@ test coroutine-3.6 {info frame, bug #2910094} -setup {
     rename stack {}
     rename a {}
 } -result {}
+test coroutine-3.7 {bug 0b874c344d} {
+    dict get [coroutine X coroutine Y info frame 0] cmd
+} {coroutine X coroutine Y info frame 0}
 
 test coroutine-4.1 {bug #2093188} -setup {
     proc foo {} {
@@ -609,7 +612,6 @@ test coroutine-7.3 {yielding between coroutines} -body {
 } -cleanup {
     catch {rename juggler ""}
 } -result {{{a b c d e} ::j1 {a b c d} ::j2 {a b c} ::j3 {a b} ::j1 a ::j2} {} {} {}}
-
 test coroutine-7.4 {Bug 8ff0cb9fe1} -setup {
     proc foo {a b} {catch yield; return 1}
 } -cleanup {
@@ -617,7 +619,6 @@ test coroutine-7.4 {Bug 8ff0cb9fe1} -setup {
 } -body {
     coroutine demo lsort -command foo {a b}
 } -result {b a}
-
 test coroutine-7.5 {return codes} {
     set result {}
     foreach code {0 1 2 3 4 5} {
@@ -625,14 +626,12 @@ test coroutine-7.5 {return codes} {
     }
     set result
 } {0 1 2 3 4 5}
-
 test coroutine-7.6 {Early yield crashes} {
     proc foo args {}
     trace add execution foo enter {catch yield}
     coroutine demo foo
     rename foo {}
 } {}
-
 test coroutine-7.7 {Bug 2486550} -setup {
     interp hide {} yield
 } -body {
@@ -641,6 +640,92 @@ test coroutine-7.7 {Bug 2486550} -setup {
     demo
     interp expose {} yield
 } -result ok
+test coroutine-7.8 {yieldto context nuke: Bug a90d9331bc} -setup {
+    namespace eval cotest {}
+    set ::result ""
+} -body {
+    proc cotest::body {} {
+	lappend ::result a
+	yield OUT
+	lappend ::result b
+	yieldto ::return -level 0 123
+	lappend ::result c
+	return
+    }
+    lappend ::result [coroutine cotest cotest::body]
+    namespace delete cotest
+    namespace eval cotest {}
+    lappend ::result [cotest]
+    cotest
+    return $result
+} -returnCodes error -cleanup {
+    catch {namespace delete ::cotest}
+    catch {rename cotest ""}
+} -result {yieldto called in deleted namespace}
+test coroutine-7.9 {yieldto context nuke: Bug a90d9331bc} -setup {
+    namespace eval cotest {}
+    set ::result ""
+} -body {
+    proc cotest::body {} {
+	set y ::yieldto
+	lappend ::result a
+	yield OUT
+	lappend ::result b
+	$y ::return -level 0 123
+	lappend ::result c
+	return
+    }
+    lappend ::result [coroutine cotest cotest::body]
+    namespace delete cotest
+    namespace eval cotest {}
+    lappend ::result [cotest]
+    cotest
+    return $result
+} -returnCodes error -cleanup {
+    catch {namespace delete ::cotest}
+    catch {rename cotest ""}
+} -result {yieldto called in deleted namespace}
+test coroutine-7.10 {yieldto context nuke: Bug a90d9331bc} -setup {
+    namespace eval cotest {}
+    set ::result ""
+} -body {
+    proc cotest::body {} {
+	lappend ::result a
+	yield OUT
+	lappend ::result b
+	yieldto ::return -level 0 -cotest [namespace delete ::cotest] 123
+	lappend ::result c
+	return
+    }
+    lappend ::result [coroutine cotest cotest::body]
+    lappend ::result [cotest]
+    cotest
+    return $result
+} -returnCodes error -cleanup {
+    catch {namespace delete ::cotest}
+    catch {rename cotest ""}
+} -result {yieldto called in deleted namespace}
+test coroutine-7.11 {yieldto context nuke: Bug a90d9331bc} -setup {
+    namespace eval cotest {}
+    set ::result ""
+} -body {
+    proc cotest::body {} {
+	set y ::yieldto
+	lappend ::result a
+	yield OUT
+	lappend ::result b
+	$y ::return -level 0 -cotest [namespace delete ::cotest] 123
+	lappend ::result c
+	return
+    }
+    lappend ::result [coroutine cotest cotest::body]
+    lappend ::result [cotest]
+    cotest
+    return $result
+} -returnCodes error -cleanup {
+    catch {namespace delete ::cotest}
+    catch {rename cotest ""}
+} -result {yieldto called in deleted namespace}
 
 
 # cleanup
diff --git a/tests/env.test b/tests/env.test
index 8115652..83d99e0 100644
--- a/tests/env.test
+++ b/tests/env.test
@@ -218,8 +218,8 @@ test env-4.5 {unsetting international environment variables} -setup {
     unset env(\ua7)
     getenv
 } -constraints {exec} -cleanup {
-    encoding system $sysenc
     unset env(\ub6)
+    encoding system $sysenc
 } -result {\u00b6=\u00a7}
 
 test env-5.0 {corner cases - set a value, it should exist} -body {
diff --git a/tests/namespace.test b/tests/namespace.test
index f6688f1..fab0040 100644
--- a/tests/namespace.test
+++ b/tests/namespace.test
@@ -303,7 +303,7 @@ test namespace-9.4 {Tcl_Import, simple import} {
     }
     test_ns_import::p
 } {cmd1: 123}
-test namespace-9.5 {Tcl_Import, can't redefine cmd unless allowOverwrite!=0} {
+test namespace-9.5 {Tcl_Import, RFE 1230597} {
     list [catch {namespace eval test_ns_import {namespace import ::test_ns_export::*}} msg] $msg
 } {0 {}}
 test namespace-9.6 {Tcl_Import, cmd redefinition ok if allowOverwrite!=0} {
@@ -558,6 +558,15 @@ test namespace-13.1 {DeleteImportedCmd, deletes imported cmds} {
         lappend l [info commands ::test_ns_import::*]
     }
 } {::test_ns_import::cmd1 {}}
+test namespace-13.2 {DeleteImportedCmd, Bug a4494e28ed} {
+    # Will panic if still buggy
+    namespace eval src {namespace export foo; proc foo {} {}}
+    namespace eval dst {namespace import [namespace parent]::src::foo}
+    trace add command src::foo delete \
+        "[list namespace delete [namespace current]::dst] ;#"
+    proc src::foo {} {}
+    namespace delete src
+} {}
 
 test namespace-14.1 {TclGetNamespaceForQualName, absolute names} {
     catch {namespace delete {*}[namespace children :: test_ns_*]}
diff --git a/tests/string.test b/tests/string.test
index 740cdc6..cf658a2 100644
--- a/tests/string.test
+++ b/tests/string.test
@@ -1398,6 +1398,9 @@ test string-15.9 {string tolower} {
 test string-15.10 {string tolower, unicode} {
      string tolower ABCabc\xc7\xe7
 } "abcabc\xe7\xe7"
+test string-15.11 {string tolower, compiled} {
+    lindex [string tolower [list A B [list C]]] 1
+} b
 
 test string-16.1 {string toupper} {
     list [catch {string toupper} msg] $msg
@@ -1429,6 +1432,9 @@ test string-16.9 {string toupper} {
 test string-16.10 {string toupper, unicode} {
     string toupper ABCabc\xc7\xe7
 } "ABCABC\xc7\xc7"
+test string-16.11 {string toupper, compiled} {
+    lindex [string toupper [list a b [list c]]] 1
+} B
 
 test string-17.1 {string totitle} {
     list [catch {string totitle} msg] $msg
@@ -1451,6 +1457,9 @@ test string-17.6 {string totitle, unicode} {
 test string-17.7 {string totitle, unicode} {
     string totitle \u01f3BCabc\xc7\xe7
 } "\u01f2bcabc\xe7\xe7"
+test string-17.8 {string totitle, compiled} {
+    lindex [string totitle [list aa bb [list cc]]] 0
+} Aa
 
 test string-18.1 {string trim} {
     list [catch {string trim} msg] $msg
diff --git a/tools/genStubs.tcl b/tools/genStubs.tcl
index b45e560..7a75dc6 100644
--- a/tools/genStubs.tcl
+++ b/tools/genStubs.tcl
@@ -283,7 +283,7 @@ proc genStubs::addPlatformGuard {plat iftxt {eltxt {}} {withCygwin 0}} {
     set text ""
     switch $plat {
 	win {
-	    append text "#if defined(__WIN32__)"
+	    append text "#if defined(_WIN32)"
 	    if {$withCygwin} {
 		append text " || defined(__CYGWIN__)"
 	    }
@@ -294,7 +294,7 @@ proc genStubs::addPlatformGuard {plat iftxt {eltxt {}} {withCygwin 0}} {
 	    append text "#endif /* WIN */\n"
 	}
 	unix {
-	    append text "#if !defined(__WIN32__)"
+	    append text "#if !defined(_WIN32)"
 	    if {$withCygwin} {
 		append text " && !defined(__CYGWIN__)"
 	    }
@@ -320,7 +320,7 @@ proc genStubs::addPlatformGuard {plat iftxt {eltxt {}} {withCygwin 0}} {
 	    append text "#endif /* AQUA */\n"
 	}
 	x11 {
-	    append text "#if !(defined(__WIN32__)"
+	    append text "#if !(defined(_WIN32)"
 	    if {$withCygwin} {
 		append text " || defined(__CYGWIN__)"
 	    }
diff --git a/tools/man2help2.tcl b/tools/man2help2.tcl
index fe4e7ad..9c8f503 100644
--- a/tools/man2help2.tcl
+++ b/tools/man2help2.tcl
@@ -717,7 +717,7 @@ proc char {name} {
 	    textSetup
 	    puts -nonewline $file "\\'d7 "
 	}
-	{\(em} {
+	{\(em} - {\(en} {
 	    textSetup
 	    puts -nonewline $file "-"
 	}
diff --git a/tools/tcltk-man2html-utils.tcl b/tools/tcltk-man2html-utils.tcl
index bdd0079..8fd1245 100644
--- a/tools/tcltk-man2html-utils.tcl
+++ b/tools/tcltk-man2html-utils.tcl
@@ -142,6 +142,7 @@ proc process-text {text} {
 	    {\(+-}	"&#177;" \
 	    {\(co}	"&copy;" \
 	    {\(em}	"&#8212;" \
+	    {\(en}	"&#8211;" \
 	    {\(fm}	"&#8242;" \
 	    {\(mu}	"&#215;" \
 	    {\(mi}	"&#8722;" \
diff --git a/unix/Makefile.in b/unix/Makefile.in
index 6c09473..69dd14f 100644
--- a/unix/Makefile.in
+++ b/unix/Makefile.in
@@ -613,7 +613,7 @@ SRCS = $(GENERIC_SRCS) $(TOMMATH_SRCS) $(UNIX_SRCS) $(NOTIFY_SRCS) \
 
 all: binaries libraries doc packages
 
-binaries: ${LIB_FILE} $(STUB_LIB_FILE) ${TCL_EXE}
+binaries: ${LIB_FILE} ${TCL_EXE}
 
 libraries:
 
@@ -621,11 +621,14 @@ doc:
 
 # The following target is configured by autoconf to generate either a shared
 # library or non-shared library for Tcl.
-${LIB_FILE}: ${OBJS} ${STUB_LIB_FILE}
+${LIB_FILE}: ${STUB_LIB_FILE} ${OBJS}
 	rm -f $@
 	@MAKE_LIB@
 
 ${STUB_LIB_FILE}: ${STUB_LIB_OBJS}
+	@if test "x${LIB_FILE}" = "xlibtcl${MAJOR_VERSION}.${MINOR_VERSION}.dll"; then \
+	    (cd ${TOP_DIR}/win; ${MAKE} tcldde14.dll tclreg13.dll); \
+	fi
 	rm -f $@
 	@MAKE_STUB_LIB@
 
@@ -849,8 +852,8 @@ install-libraries: libraries
 	    done;
 	@echo "Installing package msgcat 1.5.2 as a Tcl Module";
 	@$(INSTALL_DATA) $(TOP_DIR)/library/msgcat/msgcat.tcl "$(SCRIPT_INSTALL_DIR)"/../tcl8/8.5/msgcat-1.5.2.tm;
-	@echo "Installing package tcltest 2.3.6 as a Tcl Module";
-	@$(INSTALL_DATA) $(TOP_DIR)/library/tcltest/tcltest.tcl "$(SCRIPT_INSTALL_DIR)"/../tcl8/8.5/tcltest-2.3.6.tm;
+	@echo "Installing package tcltest 2.3.7 as a Tcl Module";
+	@$(INSTALL_DATA) $(TOP_DIR)/library/tcltest/tcltest.tcl "$(SCRIPT_INSTALL_DIR)"/../tcl8/8.5/tcltest-2.3.7.tm;
 
 	@echo "Installing package platform 1.0.12 as a Tcl Module";
 	@$(INSTALL_DATA) $(TOP_DIR)/library/platform/platform.tcl "$(SCRIPT_INSTALL_DIR)"/../tcl8/8.4/platform-1.0.12.tm;
@@ -1032,6 +1035,7 @@ IOHDR=$(GENERIC_DIR)/tclIO.h
 MATHHDRS=$(GENERIC_DIR)/tommath.h $(GENERIC_DIR)/tclTomMath.h
 PARSEHDR=$(GENERIC_DIR)/tclParse.h
 NREHDR=$(GENERIC_DIR)/tclInt.h
+TRIMHDR=$(GENERIC_DIR)/tclStringTrim.h
 
 regcomp.o: $(REGHDRS) $(GENERIC_DIR)/regcomp.c $(GENERIC_DIR)/regc_lex.c \
 		$(GENERIC_DIR)/regc_color.c $(GENERIC_DIR)/regc_locale.c \
@@ -1077,7 +1081,7 @@ tclCmdAH.o: $(GENERIC_DIR)/tclCmdAH.c
 tclCmdIL.o: $(GENERIC_DIR)/tclCmdIL.c $(TCLREHDRS)
 	$(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tclCmdIL.c
 
-tclCmdMZ.o: $(GENERIC_DIR)/tclCmdMZ.c $(TCLREHDRS)
+tclCmdMZ.o: $(GENERIC_DIR)/tclCmdMZ.c $(TCLREHDRS) $(TRIMHDR)
 	$(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tclCmdMZ.c
 
 tclDate.o: $(GENERIC_DIR)/tclDate.c
@@ -1089,7 +1093,7 @@ tclCompCmds.o: $(GENERIC_DIR)/tclCompCmds.c $(COMPILEHDR)
 tclCompCmdsGR.o: $(GENERIC_DIR)/tclCompCmdsGR.c $(COMPILEHDR)
 	$(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tclCompCmdsGR.c
 
-tclCompCmdsSZ.o: $(GENERIC_DIR)/tclCompCmdsSZ.c $(COMPILEHDR)
+tclCompCmdsSZ.o: $(GENERIC_DIR)/tclCompCmdsSZ.c $(COMPILEHDR) $(TRIMHDR)
 	$(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tclCompCmdsSZ.c
 
 tclCompExpr.o: $(GENERIC_DIR)/tclCompExpr.c $(COMPILEHDR)
@@ -1192,6 +1196,7 @@ tclLoadDld.o: $(UNIX_DIR)/tclLoadDld.c
 	$(CC) -c $(CC_SWITCHES) $(UNIX_DIR)/tclLoadDld.c
 
 tclLoadDyld.o: $(UNIX_DIR)/tclLoadDyld.c
+	@echo Warnings are expected from compiling tclLoadDyld.c: deprecated API use
 	$(CC) -c $(CC_SWITCHES) $(UNIX_DIR)/tclLoadDyld.c
 
 tclLoadNone.o: $(GENERIC_DIR)/tclLoadNone.c
@@ -1305,7 +1310,7 @@ tclStubInit.o: $(GENERIC_DIR)/tclStubInit.c
 tclTrace.o: $(GENERIC_DIR)/tclTrace.c
 	$(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tclTrace.c
 
-tclUtil.o: $(GENERIC_DIR)/tclUtil.c $(PARSEHDR)
+tclUtil.o: $(GENERIC_DIR)/tclUtil.c $(PARSEHDR) $(TRIMHDR)
 	$(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tclUtil.c
 
 tclUtf.o: $(GENERIC_DIR)/tclUtf.c $(GENERIC_DIR)/tclUniData.c
diff --git a/unix/configure b/unix/configure
index 06ff7a4..d3951b6 100755
--- a/unix/configure
+++ b/unix/configure
@@ -6490,80 +6490,6 @@ if test "${tcl_cv_cc_visibility_hidden+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
 
-	    if test "$SHARED_BUILD" = 1; then
-
-		hold_cflags=$CFLAGS; CFLAGS="$CFLAGS -fvisibility=hidden -Werror"
-		cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-#if !defined(__GNUC__) || __GNUC__ < 4
-#error visibility hidden is not supported for this compiler
-#endif
-
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext
-if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
-  (eval $ac_compile) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"
-			 || test ! -s conftest.err'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest.$ac_objext'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  tcl_cv_cc_visibility_hidden=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-tcl_cv_cc_visibility_hidden=no
-fi
-rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
-		CFLAGS=$hold_cflags
-
-else
-
-		tcl_cv_cc_visibility_hidden=no
-
-fi
-
-
-fi
-echo "$as_me:$LINENO: result: $tcl_cv_cc_visibility_hidden" >&5
-echo "${ECHO_T}$tcl_cv_cc_visibility_hidden" >&6
-    if test $tcl_cv_cc_visibility_hidden = yes; then
-
-	CFLAGS="$CFLAGS -fvisibility=hidden"
-
-cat >>confdefs.h <<\_ACEOF
-#define MODULE_SCOPE extern
-_ACEOF
-
-
-else
-
 	hold_cflags=$CFLAGS; CFLAGS="$CFLAGS -Werror"
 	cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
@@ -6614,7 +6540,10 @@ fi
 rm -f conftest.err conftest.$ac_objext \
       conftest$ac_exeext conftest.$ac_ext
 	CFLAGS=$hold_cflags
-	if test $tcl_cv_cc_visibility_hidden = yes; then
+fi
+echo "$as_me:$LINENO: result: $tcl_cv_cc_visibility_hidden" >&5
+echo "${ECHO_T}$tcl_cv_cc_visibility_hidden" >&6
+    if test $tcl_cv_cc_visibility_hidden = yes; then
 
 
 cat >>confdefs.h <<\_ACEOF
@@ -6630,9 +6559,6 @@ _ACEOF
 fi
 
 
-fi
-
-
     # Step 0.d: Disable -rpath support?
 
     echo "$as_me:$LINENO: checking if rpath support is requested" >&5
@@ -7082,6 +7008,7 @@ fi
 	    TCL_NEEDS_EXP_FILE=1
 	    TCL_EXPORT_FILE_SUFFIX='${VERSION}\$\{DBGX\}.dll.a'
 	    TCL_SHLIB_LD_EXTRAS='-Wl,--out-implib,$@.a'
+	    TK_SHLIB_LD_EXTRAS='-Wl,--out-implib,$@.a'
 	    echo "$as_me:$LINENO: checking for Cygwin version of gcc" >&5
 echo $ECHO_N "checking for Cygwin version of gcc... $ECHO_C" >&6
 if test "${ac_cv_cygwin+set}" = set; then
@@ -7150,10 +7077,15 @@ echo "$as_me: error: ${CC} is not a cygwin compiler." >&2;}
 echo "$as_me: error: CYGWIN compile is only supported with --enable-threads" >&2;}
    { (exit 1); exit 1; }; }
 	    fi
-	    if test "x${SHARED_BUILD}" = "x1" -a ! -f "../win/tcldde14.dll" -a ! -f "../win/tk86.dll"; then
-		{ { echo "$as_me:$LINENO: error: Please configure and make the ../win directory first." >&5
-echo "$as_me: error: Please configure and make the ../win directory first." >&2;}
-   { (exit 1); exit 1; }; }
+	    do64bit_ok=yes
+	    if test "x${SHARED_BUILD}" = "x1"; then
+		echo "running cd ../win; ${CONFIG_SHELL-/bin/sh} ./configure $ac_configure_args"
+		# The eval makes quoting arguments work.
+		if cd ../win; eval ${CONFIG_SHELL-/bin/sh} ./configure $ac_configure_args; cd ../unix
+		then :
+		else
+		    { echo "configure: error: configure failed for ../win" 1>&2; exit 1; }
+		fi
 	    fi
 	    ;;
 	dgux*)
@@ -7810,6 +7742,7 @@ fi
 	    SHLIB_CFLAGS="-fPIC"
 	    SHLIB_LD="${CC} -shared"
 	    TCL_SHLIB_LD_EXTRAS="-Wl,-soname=\$@"
+	    TK_SHLIB_LD_EXTRAS="-Wl,-soname,\$@"
 	    SHLIB_SUFFIX=".so"
 	    DL_OBJS="tclLoadDl.o"
 	    DL_LIBS=""
@@ -8145,7 +8078,6 @@ cat >>confdefs.h <<\_ACEOF
 #define MODULE_SCOPE __private_extern__
 _ACEOF
 
-		tcl_cv_cc_visibility_hidden=yes
 
 fi
 
diff --git a/unix/tcl.m4 b/unix/tcl.m4
index 194cf90..cb6704b 100644
--- a/unix/tcl.m4
+++ b/unix/tcl.m4
@@ -111,9 +111,9 @@ AC_DEFUN([SC_PATH_TCLCONFIG], [
 			`ls -dr ${srcdir}/../tcl[[8-9]].[[0-9]] 2>/dev/null` \
 			`ls -dr ${srcdir}/../tcl[[8-9]].[[0-9]]* 2>/dev/null` ; do
 		    if test -f "$i/unix/tclConfig.sh" ; then
-		    ac_cv_c_tclconfig="`(cd $i/unix; pwd)`"
-		    break
-		fi
+			ac_cv_c_tclconfig="`(cd $i/unix; pwd)`"
+			break
+		    fi
 		done
 	    fi
 	])
@@ -271,11 +271,10 @@ AC_DEFUN([SC_PATH_TKCONFIG], [
 #
 # Results:
 #
-#	Subst the following vars:
+#	Substitutes the following vars:
 #		TCL_BIN_DIR
 #		TCL_SRC_DIR
 #		TCL_LIB_FILE
-#
 #------------------------------------------------------------------------
 
 AC_DEFUN([SC_LOAD_TCLCONFIG], [
@@ -439,11 +438,11 @@ AC_DEFUN([SC_LOAD_TKCONFIG], [
 #	extension can't assume that an executable Tcl shell exists at
 #	build time.
 #
-# Arguments
+# Arguments:
 #	none
 #
-# Results
-#	Subst's the following values:
+# Results:
+#	Substitutes the following vars:
 #		TCLSH_PROG
 #------------------------------------------------------------------------
 
@@ -484,11 +483,11 @@ AC_DEFUN([SC_PROG_TCLSH], [
 #	when running tests from an extension build directory. It is not
 #	correct to use the TCLSH_PROG in cases like this.
 #
-# Arguments
+# Arguments:
 #	none
 #
-# Results
-#	Subst's the following values:
+# Results:
+#	Substitutes the following values:
 #		BUILD_TCLSH
 #------------------------------------------------------------------------
 
@@ -790,7 +789,6 @@ AC_DEFUN([SC_ENABLE_SYMBOLS], [
 #
 #	Defines the following vars:
 #		HAVE_LANGINFO	Triggers use of nl_langinfo if defined.
-#
 #------------------------------------------------------------------------
 
 AC_DEFUN([SC_ENABLE_LANGINFO], [
@@ -1045,34 +1043,17 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 
     AC_CACHE_CHECK([if compiler supports visibility "hidden"],
 	tcl_cv_cc_visibility_hidden, [
-	    AS_IF([test "$SHARED_BUILD" = 1], [
-		hold_cflags=$CFLAGS; CFLAGS="$CFLAGS -fvisibility=hidden -Werror"
-		AC_TRY_COMPILE(,[#if !defined(__GNUC__) || __GNUC__ < 4
-#error visibility hidden is not supported for this compiler
-#endif
-		], tcl_cv_cc_visibility_hidden=yes,
-		    tcl_cv_cc_visibility_hidden=no)
-		CFLAGS=$hold_cflags
-	    ], [
-		tcl_cv_cc_visibility_hidden=no
-	    ])
-    ])
-    AS_IF([test $tcl_cv_cc_visibility_hidden = yes], [
-	CFLAGS="$CFLAGS -fvisibility=hidden"
-	AC_DEFINE(MODULE_SCOPE, [extern], [No need to mark inidividual symbols as hidden])
-    ], [
 	hold_cflags=$CFLAGS; CFLAGS="$CFLAGS -Werror"
 	AC_TRY_LINK([
 	    extern __attribute__((__visibility__("hidden"))) void f(void);
 	    void f(void) {}], [f();], tcl_cv_cc_visibility_hidden=yes,
 	    tcl_cv_cc_visibility_hidden=no)
-	CFLAGS=$hold_cflags
-	AS_IF([test $tcl_cv_cc_visibility_hidden = yes], [
-	    AC_DEFINE(MODULE_SCOPE,
-		[extern __attribute__((__visibility__("hidden")))],
-		[Compiler support for module scope symbols])
-	    AC_DEFINE(HAVE_HIDDEN, [1], [Compiler support for module scope symbols])
-	])
+	CFLAGS=$hold_cflags])
+    AS_IF([test $tcl_cv_cc_visibility_hidden = yes], [
+	AC_DEFINE(MODULE_SCOPE,
+	    [extern __attribute__((__visibility__("hidden")))],
+	    [Compiler support for module scope symbols])
+	AC_DEFINE(HAVE_HIDDEN, [1], [Compiler support for module scope symbols])
     ])
 
     # Step 0.d: Disable -rpath support?
@@ -1237,6 +1218,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    TCL_NEEDS_EXP_FILE=1
 	    TCL_EXPORT_FILE_SUFFIX='${VERSION}\$\{DBGX\}.dll.a'
 	    TCL_SHLIB_LD_EXTRAS='-Wl,--out-implib,$[@].a'
+	    TK_SHLIB_LD_EXTRAS='-Wl,--out-implib,$[@].a'
 	    AC_CACHE_CHECK(for Cygwin version of gcc,
 		ac_cv_cygwin,
 		AC_TRY_COMPILE([
@@ -1253,8 +1235,15 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    if test "x${TCL_THREADS}" = "x0"; then
 		AC_MSG_ERROR([CYGWIN compile is only supported with --enable-threads])
 	    fi
-	    if test "x${SHARED_BUILD}" = "x1" -a ! -f "../win/tcldde14.dll" -a ! -f "../win/tk86.dll"; then
-		AC_MSG_ERROR([Please configure and make the ../win directory first.])
+	    do64bit_ok=yes
+	    if test "x${SHARED_BUILD}" = "x1"; then
+		echo "running cd ../win; ${CONFIG_SHELL-/bin/sh} ./configure $ac_configure_args"
+		# The eval makes quoting arguments work.
+		if cd ../win; eval ${CONFIG_SHELL-/bin/sh} ./configure $ac_configure_args; cd ../unix
+		then :
+		else
+		    { echo "configure: error: configure failed for ../win" 1>&2; exit 1; }
+		fi
 	    fi
 	    ;;
 	dgux*)
@@ -1543,6 +1532,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    SHLIB_CFLAGS="-fPIC"
 	    SHLIB_LD="${CC} -shared"
 	    TCL_SHLIB_LD_EXTRAS="-Wl,-soname=\$[@]"
+	    TK_SHLIB_LD_EXTRAS="-Wl,-soname,\$[@]"
 	    SHLIB_SUFFIX=".so"
 	    DL_OBJS="tclLoadDl.o"
 	    DL_LIBS=""
@@ -1638,7 +1628,6 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    AS_IF([test "$tcl_cv_cc_visibility_hidden" != yes], [
 		AC_DEFINE(MODULE_SCOPE, [__private_extern__],
 		    [Compiler support for module scope symbols])
-		tcl_cv_cc_visibility_hidden=yes
 	    ])
 	    CC_SEARCH_FLAGS=""
 	    LD_SEARCH_FLAGS=""
diff --git a/unix/tclConfig.sh.in b/unix/tclConfig.sh.in
index d47e686..b58e9fd 100644
--- a/unix/tclConfig.sh.in
+++ b/unix/tclConfig.sh.in
@@ -165,5 +165,5 @@ TCL_BUILD_STUB_LIB_PATH='@TCL_BUILD_STUB_LIB_PATH@'
 # Path to the Tcl stub library in the install directory.
 TCL_STUB_LIB_PATH='@TCL_STUB_LIB_PATH@'
 
-# Flag, 1: we built Tcl with threads enables, 0 we didn't
+# Flag, 1: we built Tcl with threads enabled, 0 we didn't
 TCL_THREADS=@TCL_THREADS@
diff --git a/unix/tclUnixInit.c b/unix/tclUnixInit.c
index f07b123..1617cba 100644
--- a/unix/tclUnixInit.c
+++ b/unix/tclUnixInit.c
@@ -33,7 +33,10 @@
 #endif
 
 #ifdef __CYGWIN__
-DLLIMPORT extern __stdcall unsigned char GetVersionExA(void *);
+DLLIMPORT extern __stdcall unsigned char GetVersionExW(void *);
+DLLIMPORT extern __stdcall void *LoadLibraryW(const void *);
+DLLIMPORT extern __stdcall void FreeLibrary(void *);
+DLLIMPORT extern __stdcall void *GetProcAddress(void *, const char *);
 DLLIMPORT extern __stdcall void GetSystemInfo(void *);
 
 #define NUMPLATFORMS 4
@@ -66,14 +69,14 @@ typedef struct _SYSTEM_INFO {
   int      wProcessorRevision;
 } SYSTEM_INFO;
 
-typedef struct _OSVERSIONINFOA {
+typedef struct _OSVERSIONINFOW {
   DWORD dwOSVersionInfoSize;
   DWORD dwMajorVersion;
   DWORD dwMinorVersion;
   DWORD dwBuildNumber;
   DWORD dwPlatformId;
-  char szCSDVersion[128];
-} OSVERSIONINFOA;
+  wchar_t szCSDVersion[128];
+} OSVERSIONINFOW;
 #endif
 
 #ifdef HAVE_COREFOUNDATION
@@ -747,7 +750,8 @@ TclpSetVariables(
 {
 #ifdef __CYGWIN__
     SYSTEM_INFO sysInfo;
-    OSVERSIONINFOA osInfo;
+    static OSVERSIONINFOW osInfo;
+    static int osInfoInitialized = 0;
     char buffer[TCL_INTEGER_SPACE * 2];
 #elif !defined(NO_UNAME)
     struct utsname name;
@@ -860,8 +864,20 @@ TclpSetVariables(
     unameOK = 0;
 #ifdef __CYGWIN__
 	unameOK = 1;
-    osInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFOA);
-    GetVersionExA(&osInfo);
+    if (!osInfoInitialized) {
+	HANDLE handle = LoadLibraryW(L"NTDLL");
+	int(__stdcall *getversion)(void *) =
+		(int(__stdcall *)(void *))GetProcAddress(handle, "RtlGetVersion");
+	osInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFOW);
+	if (!getversion || getversion(&osInfo)) {
+	    GetVersionExW(&osInfo);
+	}
+	if (handle) {
+	    FreeLibrary(handle);
+	}
+	osInfoInitialized = 1;
+    }
+
     GetSystemInfo(&sysInfo);
 
     if (osInfo.dwPlatformId < NUMPLATFORMS) {
diff --git a/win/Makefile.in b/win/Makefile.in
index bc1205a..fd80010 100644
--- a/win/Makefile.in
+++ b/win/Makefile.in
@@ -446,13 +446,13 @@ ${TCL_LIB_FILE}: ${TCL_OBJS} ${DDE_OBJS} ${REG_OBJS}
 	@MAKE_LIB@ ${TCL_OBJS} ${DDE_OBJS} ${REG_OBJS}
 	@POST_MAKE_LIB@
 
-${DDE_DLL_FILE}: ${DDE_OBJS} ${TCL_STUB_LIB_FILE}
+${DDE_DLL_FILE}: ${TCL_STUB_LIB_FILE} ${DDE_OBJS}
 	@MAKE_DLL@ ${DDE_OBJS} $(TCL_STUB_LIB_FILE) $(SHLIB_LD_LIBS)
 
-${REG_DLL_FILE}: ${REG_OBJS} ${TCL_STUB_LIB_FILE}
+${REG_DLL_FILE}: ${TCL_STUB_LIB_FILE} ${REG_OBJS}
 	@MAKE_DLL@ ${REG_OBJS} $(TCL_STUB_LIB_FILE) $(SHLIB_LD_LIBS)
 
-${TEST_DLL_FILE}: ${TCLTEST_OBJS} ${TCL_STUB_LIB_FILE}
+${TEST_DLL_FILE}: ${TCL_STUB_LIB_FILE} ${TCLTEST_OBJS}
 	@$(RM) ${TEST_DLL_FILE} ${TEST_LIB_FILE}
 	@MAKE_DLL@ ${TCLTEST_OBJS} $(TCL_STUB_LIB_FILE) $(SHLIB_LD_LIBS)
 
@@ -650,8 +650,8 @@ install-libraries: libraries install-tzdata install-msgs
 	    done;
 	@echo "Installing package msgcat 1.5.2 as a Tcl Module";
 	@$(COPY) $(ROOT_DIR)/library/msgcat/msgcat.tcl $(SCRIPT_INSTALL_DIR)/../tcl8/8.5/msgcat-1.5.2.tm;
-	@echo "Installing package tcltest 2.3.6 as a Tcl Module";
-	@$(COPY) $(ROOT_DIR)/library/tcltest/tcltest.tcl $(SCRIPT_INSTALL_DIR)/../tcl8/8.5/tcltest-2.3.6.tm;
+	@echo "Installing package tcltest 2.3.7 as a Tcl Module";
+	@$(COPY) $(ROOT_DIR)/library/tcltest/tcltest.tcl $(SCRIPT_INSTALL_DIR)/../tcl8/8.5/tcltest-2.3.7.tm;
 	@echo "Installing package platform 1.0.12 as a Tcl Module";
 	@$(COPY) $(ROOT_DIR)/library/platform/platform.tcl $(SCRIPT_INSTALL_DIR)/../tcl8/8.4/platform-1.0.12.tm;
 	@echo "Installing package platform::shell 1.1.4 as a Tcl Module";
diff --git a/win/configure b/win/configure
index d614ad5..2affd38 100755
--- a/win/configure
+++ b/win/configure
@@ -309,7 +309,7 @@ ac_includes_default="\
 # include <unistd.h>
 #endif"
 
-ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS CC CFLAGS LDFLAGS CPPFLAGS ac_ct_CC EXEEXT OBJEXT CPP EGREP AR ac_ct_AR RANLIB ac_ct_RANLIB RC ac_ct_RC SET_MAKE TCL_THREADS CYGPATH CELIB_DIR DL_LIBS CFLAGS_DEBUG CFLAGS_OPTIMIZE CFLAGS_WARNING ZLIB_DLL_FILE ZLIB_LIBS ZLIB_OBJS CFLAGS_DEFAULT LDFLAGS_DEFAULT VC_MANIFEST_EMBED_DLL VC_MANIFEST_EMBED_EXE TCL_VERSION TCL_MAJOR_VERSION TCL_MINOR_VERSION TCL_PATCH_LEVEL PKG_CFG_ARGS TCL_EXE TCL_LIB_FILE TCL_LIB_FLAG TCL_STATIC_LIB_FILE TCL_STATIC_LIB_FLAG TCL_IMPORT_LIB_FILE TCL_IMPORT_LIB_FLAG TCL_LIB_SPEC TCL_STUB_LIB_FILE TCL_STUB_LIB_FLAG TCL_STUB_LIB_SPEC TCL_STUB_LIB_PATH TCL_INCLUDE_SPEC TCL_BUILD_STUB_LIB_SPEC TCL_BUILD_STUB_LIB_PATH TCL_DLL_FILE TCL_SRC_DIR TCL_BIN_DIR TCL_DBGX CFG_TCL_SHARED_LIB_SUFFIX CFG_TCL_UNSHARED_LIB_SUFFIX CFG_TCL_EXPORT_FILE_SUFFIX EXTRA_CFLAGS DEPARG CC_OBJNAME CC_EXENAME LDFLAGS_DEBUG LDFLAGS_OPTIMIZE LDFLAGS_CONSOLE LDFLAGS_WINDOW STLIB_LD SHLIB_LD SHLIB_LD_LIBS SHLIB_CFLAGS SHLIB_SUFFIX TCL_SHARED_BUILD LIBS_GUI DLLSUFFIX LIBPREFIX LIBSUFFIX EXESUFFIX LIBRARIES MAKE_LIB MAKE_STUB_LIB POST_MAKE_LIB MAKE_DLL MAKE_EXE TCL_BUILD_LIB_SPEC TCL_LD_SEARCH_FLAGS TCL_NEEDS_EXP_FILE TCL_BUILD_EXP_FILE TCL_EXP_FILE TCL_LIB_VERSIONS_OK TCL_PACKAGE_PATH TCL_DDE_VERSION TCL_DDE_MAJOR_VERSION TCL_DDE_MINOR_VERSION TCL_REG_VERSION TCL_REG_MAJOR_VERSION TCL_REG_MINOR_VERSION RC_OUT RC_TYPE RC_INCLUDE RC_DEFINE RC_DEFINES RES LIBOBJS LTLIBOBJS'
+ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS CC CFLAGS LDFLAGS CPPFLAGS ac_ct_CC EXEEXT OBJEXT CPP EGREP AR ac_ct_AR RANLIB ac_ct_RANLIB RC ac_ct_RC SET_MAKE TCL_THREADS CYGPATH CELIB_DIR DL_LIBS CFLAGS_DEBUG CFLAGS_OPTIMIZE CFLAGS_WARNING ZLIB_DLL_FILE ZLIB_LIBS ZLIB_OBJS CFLAGS_DEFAULT LDFLAGS_DEFAULT VC_MANIFEST_EMBED_DLL VC_MANIFEST_EMBED_EXE TCL_WIN_VERSION MACHINE TCL_VERSION TCL_MAJOR_VERSION TCL_MINOR_VERSION TCL_PATCH_LEVEL PKG_CFG_ARGS TCL_EXE TCL_LIB_FILE TCL_LIB_FLAG TCL_STATIC_LIB_FILE TCL_STATIC_LIB_FLAG TCL_IMPORT_LIB_FILE TCL_IMPORT_LIB_FLAG TCL_LIB_SPEC TCL_STUB_LIB_FILE TCL_STUB_LIB_FLAG TCL_STUB_LIB_SPEC TCL_STUB_LIB_PATH TCL_INCLUDE_SPEC TCL_BUILD_STUB_LIB_SPEC TCL_BUILD_STUB_LIB_PATH TCL_DLL_FILE TCL_SRC_DIR TCL_BIN_DIR TCL_DBGX CFG_TCL_SHARED_LIB_SUFFIX CFG_TCL_UNSHARED_LIB_SUFFIX CFG_TCL_EXPORT_FILE_SUFFIX EXTRA_CFLAGS DEPARG CC_OBJNAME CC_EXENAME LDFLAGS_DEBUG LDFLAGS_OPTIMIZE LDFLAGS_CONSOLE LDFLAGS_WINDOW STLIB_LD SHLIB_LD SHLIB_LD_LIBS SHLIB_CFLAGS SHLIB_SUFFIX TCL_SHARED_BUILD LIBS_GUI DLLSUFFIX LIBPREFIX LIBSUFFIX EXESUFFIX LIBRARIES MAKE_LIB MAKE_STUB_LIB POST_MAKE_LIB MAKE_DLL MAKE_EXE TCL_BUILD_LIB_SPEC TCL_LD_SEARCH_FLAGS TCL_NEEDS_EXP_FILE TCL_BUILD_EXP_FILE TCL_EXP_FILE TCL_LIB_VERSIONS_OK TCL_PACKAGE_PATH TCL_DDE_VERSION TCL_DDE_MAJOR_VERSION TCL_DDE_MINOR_VERSION TCL_REG_VERSION TCL_REG_MAJOR_VERSION TCL_REG_MINOR_VERSION RC_OUT RC_TYPE RC_INCLUDE RC_DEFINE RC_DEFINES RES LIBOBJS LTLIBOBJS'
 ac_subst_files=''
 
 # Initialize some variables set by options.
@@ -3340,7 +3340,7 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-	    #ifndef __WIN32__
+	    #ifndef _WIN32
 		#error cross-compiler
 	    #endif
 
@@ -3463,7 +3463,7 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-		#ifdef __WIN32__
+		#ifdef _WIN32
 		    #error win32
 		#endif
 
@@ -5168,6 +5168,19 @@ else
     TCL_PACKAGE_PATH="${prefix}/lib"
 fi
 
+# The tclsh.exe.manifest requires these
+# TCL_WIN_VERSION is the 4 dotted pair Windows version format which needs
+# the release level, and must account for interim release versioning
+case "$TCL_PATCH_LEVEL" in
+     *a*) TCL_RELEASE_LEVEL=0 ;;
+     *b*) TCL_RELEASE_LEVEL=1 ;;
+     *)   TCL_RELEASE_LEVEL=2 ;;
+esac
+TCL_WIN_VERSION="$TCL_VERSION.$TCL_RELEASE_LEVEL.`echo $TCL_PATCH_LEVEL | tr -d ab.`"
+
+# X86|AMD64|IA64 for manifest
+
+
 
 
 
@@ -5262,7 +5275,7 @@ fi
 
 
 
-                              ac_config_files="$ac_config_files Makefile tclConfig.sh tcl.hpj"
+                                        ac_config_files="$ac_config_files Makefile tclConfig.sh tcl.hpj tclsh.exe.manifest"
 cat >confcache <<\_ACEOF
 # This file is a shell script that caches the results of configure
 # tests run on this system so they can be shared between configure
@@ -5816,6 +5829,7 @@ do
   "Makefile" ) CONFIG_FILES="$CONFIG_FILES Makefile" ;;
   "tclConfig.sh" ) CONFIG_FILES="$CONFIG_FILES tclConfig.sh" ;;
   "tcl.hpj" ) CONFIG_FILES="$CONFIG_FILES tcl.hpj" ;;
+  "tclsh.exe.manifest" ) CONFIG_FILES="$CONFIG_FILES tclsh.exe.manifest" ;;
   *) { { echo "$as_me:$LINENO: error: invalid argument: $ac_config_target" >&5
 echo "$as_me: error: invalid argument: $ac_config_target" >&2;}
    { (exit 1); exit 1; }; };;
@@ -5929,6 +5943,8 @@ s,@CFLAGS_DEFAULT@,$CFLAGS_DEFAULT,;t t
 s,@LDFLAGS_DEFAULT@,$LDFLAGS_DEFAULT,;t t
 s,@VC_MANIFEST_EMBED_DLL@,$VC_MANIFEST_EMBED_DLL,;t t
 s,@VC_MANIFEST_EMBED_EXE@,$VC_MANIFEST_EMBED_EXE,;t t
+s,@TCL_WIN_VERSION@,$TCL_WIN_VERSION,;t t
+s,@MACHINE@,$MACHINE,;t t
 s,@TCL_VERSION@,$TCL_VERSION,;t t
 s,@TCL_MAJOR_VERSION@,$TCL_MAJOR_VERSION,;t t
 s,@TCL_MINOR_VERSION@,$TCL_MINOR_VERSION,;t t
diff --git a/win/configure.in b/win/configure.in
index 4cc1e9f..77e0327 100644
--- a/win/configure.in
+++ b/win/configure.in
@@ -350,6 +350,19 @@ else
     TCL_PACKAGE_PATH="${prefix}/lib"
 fi
 
+# The tclsh.exe.manifest requires these
+# TCL_WIN_VERSION is the 4 dotted pair Windows version format which needs
+# the release level, and must account for interim release versioning
+case "$TCL_PATCH_LEVEL" in
+     *a*) TCL_RELEASE_LEVEL=0 ;;
+     *b*) TCL_RELEASE_LEVEL=1 ;;
+     *)   TCL_RELEASE_LEVEL=2 ;;
+esac
+TCL_WIN_VERSION="$TCL_VERSION.$TCL_RELEASE_LEVEL.`echo $TCL_PATCH_LEVEL | tr -d ab.`"
+AC_SUBST(TCL_WIN_VERSION)
+# X86|AMD64|IA64 for manifest
+AC_SUBST(MACHINE)
+
 AC_SUBST(TCL_VERSION)
 AC_SUBST(TCL_MAJOR_VERSION)
 AC_SUBST(TCL_MINOR_VERSION)
@@ -444,7 +457,7 @@ AC_SUBST(RC_DEFINE)
 AC_SUBST(RC_DEFINES)
 AC_SUBST(RES)
 
-AC_OUTPUT(Makefile tclConfig.sh tcl.hpj)
+AC_OUTPUT(Makefile tclConfig.sh tcl.hpj tclsh.exe.manifest)
 
 dnl Local Variables:
 dnl mode: autoconf;
diff --git a/win/makefile.vc b/win/makefile.vc
index b76a939..e5f6c9b 100644
--- a/win/makefile.vc
+++ b/win/makefile.vc
@@ -985,6 +985,12 @@ $(TMP_DIR)\tclTomMathStubLib.obj: $(GENERICDIR)\tclTomMathStubLib.c
 $(TMP_DIR)\tclOOStubLib.obj: $(GENERICDIR)\tclOOStubLib.c
 	$(cc32) $(STUB_CFLAGS) -Zl -DSTATIC_BUILD $(TCL_INCLUDES) -Fo$@ $?
 
+$(TMP_DIR)\tclsh.exe.manifest: $(WINDIR)\tclsh.exe.manifest.in
+	@nmakehlp -s << $** >$@
+@MACHINE@	  $(MACHINE:IX86=X86)
+@TCL_WIN_VERSION@  $(DOTVERSION).0.0
+<<
+
 #---------------------------------------------------------------------
 # Generate the source dependencies.  Having dependency rules will
 # improve incremental build accuracy without having to resort to a
@@ -1051,12 +1057,14 @@ $<
 <<
 
 {$(WINDIR)}.rc{$(TMP_DIR)}.res:
-	$(rc32) -fo $@ -r -i "$(GENERICDIR)" \
+	$(rc32) -fo $@ -r -i "$(GENERICDIR)" -i "$(TMP_DIR)" \
 	    -d DEBUG=$(DEBUG) -d UNCHECKED=$(UNCHECKED) \
 	    -d TCL_THREADS=$(TCL_THREADS) \
 	    -d STATIC_BUILD=$(STATIC_BUILD) \
 	    $<
 
+$(TMP_DIR)\tclsh.res: $(TMP_DIR)\tclsh.exe.manifest
+
 .SUFFIXES:
 .SUFFIXES:.c .rc
 
diff --git a/win/tcl.m4 b/win/tcl.m4
index 52c001f..d12ae10 100644
--- a/win/tcl.m4
+++ b/win/tcl.m4
@@ -247,7 +247,7 @@ AC_DEFUN([SC_PATH_TKCONFIG], [
 #
 # Results:
 #
-#	Subst the following vars:
+#	Substitutes the following vars:
 #		TCL_BIN_DIR
 #		TCL_SRC_DIR
 #		TCL_LIB_FILE
@@ -572,7 +572,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
       AC_CACHE_CHECK(for cross-compile version of gcc,
 	ac_cv_cross,
 	AC_TRY_COMPILE([
-	    #ifndef __WIN32__
+	    #ifndef _WIN32
 		#error cross-compiler
 	    #endif
 	], [],
@@ -639,7 +639,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	AC_CACHE_CHECK(for mingw32 version of gcc,
 	    ac_cv_win32,
 	    AC_TRY_COMPILE([
-		#ifdef __WIN32__
+		#ifdef _WIN32
 		    #error win32
 		#endif
 	    ], [],
diff --git a/win/tclConfig.sh.in b/win/tclConfig.sh.in
index 65bc5c5..00a8790 100644
--- a/win/tclConfig.sh.in
+++ b/win/tclConfig.sh.in
@@ -175,6 +175,6 @@ TCL_BUILD_STUB_LIB_PATH='@TCL_BUILD_STUB_LIB_PATH@'
 # Path to the Tcl stub library in the install directory.
 TCL_STUB_LIB_PATH='@TCL_STUB_LIB_PATH@'
 
-# Flag, 1: we built Tcl with threads enables, 0 we didn't
+# Flag, 1: we built Tcl with threads enabled, 0 we didn't
 TCL_THREADS=@TCL_THREADS@
 
diff --git a/win/tclWin32Dll.c b/win/tclWin32Dll.c
index a72b760..688fa8d 100644
--- a/win/tclWin32Dll.c
+++ b/win/tclWin32Dll.c
@@ -69,7 +69,7 @@ TCL_DECLARE_MUTEX(mountPointMap)
  * We will need this below.
  */
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #ifndef STATIC_BUILD
 
 /*
@@ -137,7 +137,7 @@ DllMain(
     return TRUE;
 }
 #endif /* !STATIC_BUILD */
-#endif /* __WIN32__ */
+#endif /* _WIN32 */
 
 /*
  *----------------------------------------------------------------------
@@ -181,11 +181,11 @@ void
 TclWinInit(
     HINSTANCE hInst)		/* Library instance handle. */
 {
-    OSVERSIONINFO os;
+    OSVERSIONINFOW os;
 
     hInstance = hInst;
-    os.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
-    GetVersionEx(&os);
+    os.dwOSVersionInfoSize = sizeof(OSVERSIONINFOW);
+    GetVersionExW(&os);
     platformId = os.dwPlatformId;
 
     /*
diff --git a/win/tclWinChan.c b/win/tclWinChan.c
index 21115f7..c63aaa7 100644
--- a/win/tclWinChan.c
+++ b/win/tclWinChan.c
@@ -95,7 +95,7 @@ static void		FileThreadActionProc(ClientData instanceData,
 static int		FileTruncateProc(ClientData instanceData,
 			    Tcl_WideInt length);
 static DWORD		FileGetType(HANDLE handle);
-
+static int		NativeIsComPort(CONST TCHAR *nativeName);
 /*
  * This structure describes the channel type structure for file based IO.
  */
@@ -885,6 +885,33 @@ TclpOpenFileChannel(
     }
 
     /*
+     * [2413550] Avoid double-open of serial ports on Windows
+     * Special handling for Windows serial ports by a "name-hint"
+     * to directly open it with the OVERLAPPED flag set.
+     */
+
+    if( NativeIsComPort(nativeName) ) {
+
+	handle = TclWinSerialOpen(INVALID_HANDLE_VALUE, nativeName, accessMode);
+	if (handle == INVALID_HANDLE_VALUE) {
+	    TclWinConvertError(GetLastError());
+	    if (interp != (Tcl_Interp *) NULL) {
+		Tcl_AppendResult(interp, "couldn't open serial \"",
+			TclGetString(pathPtr), "\": ",
+			Tcl_PosixError(interp), NULL);
+	    }
+	    return NULL;
+	}
+
+	/*
+	* For natively named Windows serial ports we are done.
+	*/
+	channel = TclWinOpenSerialChannel(handle, channelName,
+		channelPermissions);
+
+	return channel;
+    }
+    /*
      * If the file is being created, get the file attributes from the
      * permissions argument, else use the existing file attributes.
      */
@@ -935,11 +962,15 @@ TclpOpenFileChannel(
     switch (FileGetType(handle)) {
     case FILE_TYPE_SERIAL:
 	/*
+	 * Natively named serial ports "com1-9", "\\\\.\\comXX" are 
+	 * already done with the code above.
+	 * Here we handle all other serial port names.
+	 *
 	 * Reopen channel for OVERLAPPED operation. Normally this shouldn't
 	 * fail, because the channel exists.
 	 */
 
-	handle = TclWinSerialReopen(handle, nativeName, accessMode);
+	handle = TclWinSerialOpen(handle, nativeName, accessMode);
 	if (handle == INVALID_HANDLE_VALUE) {
 	    TclWinConvertError(GetLastError());
 	    if (interp != (Tcl_Interp *) NULL) {
@@ -1479,6 +1510,74 @@ FileGetType(
     return type;
 }
 
+ /*
+ *----------------------------------------------------------------------
+ *
+ * NativeIsComPort --
+ *
+ *	Determines if a path refers to a Windows serial port.
+ *	A simple and efficient solution is to use a "name hint" to detect 
+ *      COM ports by their filename instead of resorting to a syscall 
+ *	to detect serialness after the fact.
+ *	The following patterns cover common serial port names:
+ *	    COM[1-9]:?
+ *	    //./COM[0-9]+
+ *	    \\.\COM[0-9]+
+ *
+ * Results:
+ *	1 = serial port, 0 = not.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+NativeIsComPort(
+    const TCHAR *nativePath)	/* Path of file to access, native encoding. */
+{
+    const WCHAR *p = (const WCHAR *) nativePath;
+    int i, len = wcslen(p);
+
+    /*
+     * 1. Look for com[1-9]:?
+     */
+
+    if ( (len >= 4) && (len <= 5) 
+	    && (_wcsnicmp(p, L"com", 3) == 0) ) {
+	/*
+	* The 4th character must be a digit 1..9 optionally followed by a ":"
+	*/
+	
+	if ( (p[3] < L'1') || (p[3] > L'9') ) {
+	    return 0;
+	}
+	if ( (len == 5) && (p[4] != L':') ) {
+	    return 0;
+	}
+	return 1;
+    }
+    
+    /*
+     * 2. Look for //./com[0-9]+ or \\.\com[0-9]+
+     */
+    
+    if ( (len >= 8) && ( 
+	       (_wcsnicmp(p, L"//./com", 7) == 0)
+	    || (_wcsnicmp(p, L"\\\\.\\com", 7) == 0) ) )
+    {
+	/*
+	* Charaters 8..end must be a digits 0..9
+	*/
+    
+	for ( i=7; i<len; i++ ) {
+	    if ( (p[i] < '0') || (p[i] > '9') ) {
+		return 0;
+	    }
+	}
+	return 1;
+    }
+    return 0;
+}
+
 /*
  * Local Variables:
  * mode: c
diff --git a/win/tclWinInit.c b/win/tclWinInit.c
index d82944e..2c21d38 100644
--- a/win/tclWinInit.c
+++ b/win/tclWinInit.c
@@ -530,7 +530,8 @@ TclpSetVariables(
 	SYSTEM_INFO info;
 	OemId oemId;
     } sys;
-    OSVERSIONINFOA osInfo;
+    static OSVERSIONINFOW osInfo;
+    static int osInfoInitialized = 0;
     Tcl_DString ds;
     TCHAR szUserName[UNLEN+1];
     DWORD cchUserNameLen = UNLEN;
@@ -538,9 +539,19 @@ TclpSetVariables(
     Tcl_SetVar2Ex(interp, "tclDefaultLibrary", NULL,
 	    TclGetProcessGlobalValue(&defaultLibraryDir), TCL_GLOBAL_ONLY);
 
-    osInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFOA);
-    GetVersionExA(&osInfo);
-
+    if (!osInfoInitialized) {
+	HANDLE handle = LoadLibraryW(L"NTDLL");
+	int(__stdcall *getversion)(void *) =
+		(int(__stdcall *)(void *)) GetProcAddress(handle, "RtlGetVersion");
+	osInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFOW);
+	if (!getversion || getversion(&osInfo)) {
+	    GetVersionExW(&osInfo);
+	}
+	if (handle) {
+		FreeLibrary(handle);
+	}
+	osInfoInitialized = 1;
+    }
     GetSystemInfo(&sys.info);
 
     /*
diff --git a/win/tclWinInt.h b/win/tclWinInt.h
index c7066bb..9df424f 100644
--- a/win/tclWinInt.h
+++ b/win/tclWinInt.h
@@ -66,7 +66,7 @@ MODULE_SCOPE Tcl_Channel TclWinOpenFileChannel(HANDLE handle, char *channelName,
 			    int permissions, int appendMode);
 MODULE_SCOPE Tcl_Channel TclWinOpenSerialChannel(HANDLE handle,
 			    char *channelName, int permissions);
-MODULE_SCOPE HANDLE	TclWinSerialReopen(HANDLE handle, const TCHAR *name,
+MODULE_SCOPE HANDLE	TclWinSerialOpen(HANDLE handle, const TCHAR *name,
 			    DWORD access);
 MODULE_SCOPE int	TclWinSymLinkCopyDirectory(const TCHAR *LinkOriginal,
 			    const TCHAR *LinkCopy);
diff --git a/win/tclWinSerial.c b/win/tclWinSerial.c
index b9c9a9f..6487fe4 100644
--- a/win/tclWinSerial.c
+++ b/win/tclWinSerial.c
@@ -1410,23 +1410,22 @@ SerialWriterThread(
 /*
  *----------------------------------------------------------------------
  *
- * TclWinSerialReopen --
+ * TclWinSerialOpen --
  *
- *	Reopens the serial port with the OVERLAPPED FLAG set
+ *	Opens or Reopens the serial port with the OVERLAPPED FLAG set
  *
  * Results:
- *	Returns the new handle, or INVALID_HANDLE_VALUE. Normally there
- *	shouldn't be any error, because the same channel has previously been
- *	succeesfully opened.
+ *	Returns the new handle, or INVALID_HANDLE_VALUE. 
+ *	If an existing channel is specified it is closed and reopened.
  *
  * Side effects:
- *	May close the original handle
+ *	May close/reopen the original handle
  *
  *----------------------------------------------------------------------
  */
 
 HANDLE
-TclWinSerialReopen(
+TclWinSerialOpen(
     HANDLE handle,
     const TCHAR *name,
     DWORD access)
@@ -1434,16 +1433,22 @@ TclWinSerialReopen(
     SerialInit();
 
     /*
+     * If an open channel is specified, close it
+     */
+
+    if ( handle != INVALID_HANDLE_VALUE && CloseHandle(handle) == FALSE) {
+	return INVALID_HANDLE_VALUE;
+    }
+
+    /*
      * Multithreaded I/O needs the overlapped flag set otherwise
      * ClearCommError blocks under Windows NT/2000 until serial output is
      * finished
      */
 
-    if (CloseHandle(handle) == FALSE) {
-	return INVALID_HANDLE_VALUE;
-    }
     handle = CreateFile(name, access, 0, 0, OPEN_EXISTING,
 	    FILE_FLAG_OVERLAPPED, 0);
+
     return handle;
 }
 
diff --git a/win/tclWinTest.c b/win/tclWinTest.c
index b83c0ba..6027e32 100644
--- a/win/tclWinTest.c
+++ b/win/tclWinTest.c
@@ -17,7 +17,7 @@
 /*
  * For TestplatformChmod on Windows
  */
-#ifdef __WIN32__
+#ifdef _WIN32
 #include <aclapi.h>
 #endif
 
diff --git a/win/tclsh.exe.manifest.in b/win/tclsh.exe.manifest.in
new file mode 100644
index 0000000..aaa34e1
--- /dev/null
+++ b/win/tclsh.exe.manifest.in
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0"
+	xmlns:asmv3="urn:schemas-microsoft-com:asm.v3">
+    <assemblyIdentity
+	    version="@TCL_WIN_VERSION@"
+	    processorArchitecture="@MACHINE@"
+	    name="Tcl.tclsh"
+	    type="win32"
+	/>
+    <description>Tcl command line shell (tclsh)</description>
+    <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+	<security>
+	    <requestedPrivileges>
+		<requestedExecutionLevel
+			level="asInvoker"
+			uiAccess="false"
+		    />
+	    </requestedPrivileges>
+	</security>
+    </trustInfo>
+    <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+	<application>
+	    <!-- Windows 8.1 -->
+	    <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/>
+	    <!-- Windows 8 -->
+	    <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/>
+	    <!-- Windows 7 -->
+	    <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>
+	    <!-- Windows Vista -->
+	    <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}"/>
+	</application>
+    </compatibility>
+</assembly>
diff --git a/win/tclsh.rc b/win/tclsh.rc
index 16eaf83..161da50 100644
--- a/win/tclsh.rc
+++ b/win/tclsh.rc
@@ -1,3 +1,4 @@
+//
 // Version Resource Script
 //
 
@@ -67,3 +68,15 @@ END
 //
 
 tclsh                      ICON    DISCARDABLE     "tclsh.ico"
+
+//
+// This is needed for Windows 8.1 onwards.
+//
+
+#ifndef RT_MANIFEST
+#define RT_MANIFEST     24
+#endif
+#ifndef CREATEPROCESS_MANIFEST_RESOURCE_ID
+#define CREATEPROCESS_MANIFEST_RESOURCE_ID 1
+#endif
+CREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "tclsh.exe.manifest"