Merge trunk. Add "--with-dbgx" configure option, so the name of the tclsh executable/sharedlibrary can be modified (request at EuroTcl 2016)

29 files changed, 339 insertions, 366 deletions

diff --git a/doc/proc.n b/doc/proc.n
index 129f4df..fdccaca 100644
--- a/doc/proc.n
+++ b/doc/proc.n
@@ -34,8 +34,9 @@ one or two fields.  If there is only a single field in the specifier
 then it is the name of the argument; if there are two fields, then
 the first is the argument name and the second is its default value.
 Arguments with default values that are followed by non-defaulted
-arguments become required arguments.  In 8.6 this will be considered an
-error.
+arguments become required arguments; enough actual arguments must be
+supplied to allow all arguments up to and including the last required
+formal argument.
 .PP
 When \fIname\fR is invoked a local variable
 will be created for each of the formal arguments to the procedure; its
@@ -48,11 +49,14 @@ actual arguments for all the
 formal arguments that do not have defaults, and there must not be any extra
 actual arguments.
 Arguments with default values that are followed by non-defaulted
-arguments become required arguments (in 8.6 it will be considered an
-error).
+arguments become de-facto required arguments, though this may change
+in a future version of Tcl; portable code should ensure that all
+optional arguments come after all required arguments.
+.PP
 There is one special case to permit procedures with
 variable numbers of arguments.  If the last formal argument has the name
-\fBargs\fR, then a call to the procedure may contain more actual arguments
+.QW \fBargs\fR ,
+then a call to the procedure may contain more actual arguments
 than the procedure has formal arguments.  In this case, all of the actual arguments
 starting at the one that would be assigned to \fBargs\fR are combined into
 a list (as if the \fBlist\fR command had been used); this combined value
@@ -80,6 +84,20 @@ If an error occurs while executing the procedure
 body, then the procedure-as-a-whole will return that same error.
 .SH EXAMPLES
 .PP
+This is a procedure that takes two arguments and prints both their sum
+and their product. It also returns the string
+.QW OK
+to the caller as an explicit result.
+.PP
+.CS
+\fBproc\fR printSumProduct {x y} {
+    set sum [expr {$x + $y}]
+    set prod [expr {$x * $y}]
+    puts "sum is $sum, product is $prod"
+    return "OK"
+}
+.CE
+.PP
 This is a procedure that accepts arbitrarily many arguments and prints
 them out, one by one.
 .PP
diff --git a/doc/zlib.n b/doc/zlib.n
index 9f3078d..fd29e0d 100644
--- a/doc/zlib.n
+++ b/doc/zlib.n
@@ -174,7 +174,11 @@ to the \fBzlib push\fR command:
 .VS "TIP 400"
 Sets the compression dictionary to use when working with compressing or
 decompressing the data to be \fIbinData\fR. Not valid for transformations that
-work with gzip-format data.
+work with gzip-format data.  The dictionary should consist of strings (byte
+sequences) that are likely to be encountered later in the data to be compressed,
+with the most commonly used strings preferably put towards the end of the
+dictionary. Tcl provides no mechanism for choosing a good such dictionary for
+a particular data sequence.
 .VE
 .TP
 \fB\-header\fI dictionary\fR
@@ -207,11 +211,13 @@ compression algorithm depends on what format is being produced or consumed.
 .TP
 \fB\-dictionary\fI binData\fR
 .VS "TIP 400"
-This read-write options gets or sets the compression dictionary to use when
-working with compressing or decompressing the data to be \fIbinData\fR. It is
-not valid for transformations that work with gzip-format data, and should not
-normally be set on compressing transformations other than at the point where
-the transformation is stacked.
+This read-write options gets or sets the initial compression dictionary to use
+when working with compressing or decompressing the data to be \fIbinData\fR.
+It is not valid for transformations that work with gzip-format data, and should
+not normally be set on compressing transformations other than at the point where
+the transformation is stacked. Note that this cannot be used to get the
+current active compression dictionary mid-stream, as that information is not
+exposed by the underlying library.
 .VE
 .TP
 \fB\-flush\fI type\fR
diff --git a/generic/tcl.h b/generic/tcl.h
index 6df3196..25f941b 100644
--- a/generic/tcl.h
+++ b/generic/tcl.h
@@ -144,6 +144,7 @@ extern "C" {
 #if defined(__GNUC__) && (__GNUC__ > 2)
 #   define TCL_FORMAT_PRINTF(a,b) __attribute__ ((__format__ (__printf__, a, b)))
 #   define TCL_NORETURN __attribute__ ((noreturn))
+#   define TCL_NOINLINE __attribute__ ((noinline))
 #   if defined(BUILD_tcl) || defined(BUILD_tk)
 #	define TCL_NORETURN1 __attribute__ ((noreturn))
 #   else
@@ -153,8 +154,10 @@ extern "C" {
 #   define TCL_FORMAT_PRINTF(a,b)
 #   if defined(_MSC_VER) && (_MSC_VER >= 1310)
 #	define TCL_NORETURN _declspec(noreturn)
+#	define TCL_NOINLINE __declspec(noinline)
 #   else
 #	define TCL_NORETURN /* nothing */
+#	define TCL_NOINLINE /* nothing */
 #   endif
 #   define TCL_NORETURN1 /* nothing */
 #endif
@@ -2374,9 +2377,6 @@ typedef int (Tcl_NRPostProc) (ClientData data[], Tcl_Interp *interp,
  *----------------------------------------------------------------------------
  * The following constant is used to test for older versions of Tcl in the
  * stubs tables.
- *
- * Jan Nijtman's plus patch uses 0xFCA1BACF, so we need to pick a different
- * value since the stubs tables don't match.
  */
 
 #define TCL_STUB_MAGIC		((int) 0xFCA3BACF)
@@ -2389,17 +2389,19 @@ typedef int (Tcl_NRPostProc) (ClientData data[], Tcl_Interp *interp,
  */
 
 const char *		Tcl_InitStubs(Tcl_Interp *interp, const char *version,
-			    int exact);
+			    int exact, int magic);
 const char *		TclTomMathInitializeStubs(Tcl_Interp *interp,
 			    const char *version, int epoch, int revision);
 
-/*
- * When not using stubs, make it a macro.
- */
-
-#ifndef USE_TCL_STUBS
+#ifdef USE_TCL_STUBS
+#define Tcl_InitStubs(interp, version, exact) \
+    (Tcl_InitStubs)(interp, version, \
+	    (exact)|(TCL_MAJOR_VERSION<<8)|(TCL_MINOR_VERSION<<16), \
+	    TCL_STUB_MAGIC)
+#else
 #define Tcl_InitStubs(interp, version, exact) \
-    Tcl_PkgInitStubsCheck(interp, version, exact)
+    Tcl_PkgInitStubsCheck(interp, version, \
+	    (exact)|(TCL_MAJOR_VERSION<<8)|(TCL_MINOR_VERSION<<16))
 #endif
 
 /*
diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index b089985..0a4b7e5 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -726,9 +726,7 @@ Tcl_CreateInterp(void)
      * Initialize the ensemble error message rewriting support.
      */
 
-    iPtr->ensembleRewrite.sourceObjs = NULL;
-    iPtr->ensembleRewrite.numRemovedObjs = 0;
-    iPtr->ensembleRewrite.numInsertedObjs = 0;
+    TclResetRewriteEnsemble(interp, 1);
 
     /*
      * TIP#143: Initialise the resource limit support.
@@ -4225,7 +4223,7 @@ EvalObjvCore(
 	 * TCL_EVAL_INVOKE was not set: clear rewrite rules
 	 */
 
-	iPtr->ensembleRewrite.sourceObjs = NULL;
+	TclResetRewriteEnsemble(interp, 1);
 
 	if (flags & TCL_EVAL_GLOBAL) {
 	    TEOV_SwitchVarFrame(interp);
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c
index 0d35397..c93e593 100644
--- a/generic/tclCmdIL.c
+++ b/generic/tclCmdIL.c
@@ -1203,7 +1203,7 @@ InfoFrameCmd(
     levelError:
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 		"bad level \"%s\"", TclGetString(objv[1])));
-	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "STACK_FRAME",
+	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LEVEL",
 		TclGetString(objv[1]), NULL);
 	code = TCL_ERROR;
 	goto done;
@@ -1638,7 +1638,7 @@ InfoLevelCmd(
   levelError:
     Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 	    "bad level \"%s\"", TclGetString(objv[1])));
-    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "STACK_LEVEL",
+    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LEVEL",
 	    TclGetString(objv[1]), NULL);
     return TCL_ERROR;
 }
diff --git a/generic/tclEnsemble.c b/generic/tclEnsemble.c
index 986a553..1c91734 100644
--- a/generic/tclEnsemble.c
+++ b/generic/tclEnsemble.c
@@ -1832,7 +1832,6 @@ NsEnsembleImplementationCmdNR(
 	Tcl_Obj *copyPtr;	/* The actual list of words to dispatch to.
 				 * Will be freed by the dispatch engine. */
 	int prefixObjc, copyObjc;
-	Interp *iPtr = (Interp *) interp;
 
 	/*
 	 * Get the prefix that we're rewriting to. To do this we need to
@@ -1876,25 +1875,10 @@ NsEnsembleImplementationCmdNR(
 	 * count both as inserted and removed arguments.
 	 */
 
-	if (iPtr->ensembleRewrite.sourceObjs == NULL) {
-	    iPtr->ensembleRewrite.sourceObjs = objv;
-	    iPtr->ensembleRewrite.numRemovedObjs =
-		    2 + ensemblePtr->numParameters;
-	    iPtr->ensembleRewrite.numInsertedObjs =
-		    prefixObjc + ensemblePtr->numParameters;
+	if (TclInitRewriteEnsemble(interp, 2 + ensemblePtr->numParameters,
+		prefixObjc + ensemblePtr->numParameters, objv)) {
 	    TclNRAddCallback(interp, TclClearRootEnsemble, NULL, NULL, NULL,
 		    NULL);
-	} else {
-	    register int ni = 2 + ensemblePtr->numParameters
-		    - iPtr->ensembleRewrite.numInsertedObjs;
-				/* Position in objv of new front of insertion
-				 * relative to old one. */
-	    if (ni > 0) {
-		iPtr->ensembleRewrite.numRemovedObjs += ni;
-		iPtr->ensembleRewrite.numInsertedObjs += prefixObjc-1;
-	    } else {
-		iPtr->ensembleRewrite.numInsertedObjs += prefixObjc-2;
-	    }
 	}
 
 	/*
@@ -2013,7 +1997,7 @@ TclInitRewriteEnsemble(
 
 	if (numIns < numRemoved) {
 	    iPtr->ensembleRewrite.numRemovedObjs += numRemoved - numIns;
-	    iPtr->ensembleRewrite.numInsertedObjs += numInserted - 1;
+	    iPtr->ensembleRewrite.numInsertedObjs = numInserted;
 	} else {
 	    iPtr->ensembleRewrite.numInsertedObjs += numInserted - numRemoved;
 	}
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index cd28a92..0a6e60e 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -2074,6 +2074,8 @@ TclNRExecuteByteCode(
      * Push the callback for bytecode execution
      */
 
+    TclResetRewriteEnsemble(interp, 1);
+
     TclNRAddCallback(interp, TEBCresume, TD, /* pc */ NULL,
 	    /* cleanup */ INT2PTR(0), NULL);
     return TCL_OK;
@@ -3172,9 +3174,8 @@ TEBCresume(
 	if (iPtr->flags & INTERP_DEBUG_FRAME) {
 	    ArgumentBCEnter(interp, codePtr, TD, pc, objc, objv);
 	}
-	iPtr->ensembleRewrite.sourceObjs = objv;
-	iPtr->ensembleRewrite.numRemovedObjs = opnd;
-	iPtr->ensembleRewrite.numInsertedObjs = 1;
+
+	TclInitRewriteEnsemble(interp, opnd, 1, objv);
 	DECACHE_STACK_INFO();
 	pc += 6;
 	TEBC_YIELD();
@@ -7706,6 +7707,7 @@ TEBCresume(
 		goto gotError;
 	    }
 	}
+	Tcl_IncrRefCount(dictPtr);
 	if (TclListObjGetElements(interp, OBJ_AT_TOS, &length,
 		&keyPtrPtr) != TCL_OK) {
 	    TRACE_ERROR(interp);
@@ -7718,6 +7720,7 @@ TEBCresume(
 	    if (Tcl_DictObjGet(interp, dictPtr, keyPtrPtr[i],
 		    &valuePtr) != TCL_OK) {
 		TRACE_ERROR(interp);
+		Tcl_DecrRefCount(dictPtr);
 		goto gotError;
 	    }
 	    varPtr = LOCAL(duiPtr->varIndices[i]);
@@ -7734,10 +7737,12 @@ TEBCresume(
 		    duiPtr->varIndices[i]) == NULL) {
 		CACHE_STACK_INFO();
 		TRACE_ERROR(interp);
+		Tcl_DecrRefCount(dictPtr);
 		goto gotError;
 	    }
 	    CACHE_STACK_INFO();
 	}
+	TclDecrRefCount(dictPtr);
 	TRACE_APPEND(("OK\n"));
 	NEXT_INST_F(9, 0, 0);
 
diff --git a/generic/tclInterp.c b/generic/tclInterp.c
index 9c4a157..1455c7d 100644
--- a/generic/tclInterp.c
+++ b/generic/tclInterp.c
@@ -1796,11 +1796,9 @@ AliasNRCmd(
     int objc,			/* Number of arguments. */
     Tcl_Obj *const objv[])	/* Argument vector. */
 {
-    Interp *iPtr = (Interp *) interp;
     Alias *aliasPtr = clientData;
     int prefc, cmdc, i;
     Tcl_Obj **prefv, **cmdv;
-    int isRootEnsemble = (iPtr->ensembleRewrite.sourceObjs == NULL);
     Tcl_Obj *listPtr;
     List *listRep;
     int flags = TCL_EVAL_INVOKE;
@@ -1832,21 +1830,7 @@ AliasNRCmd(
      * only the source command should show, not the full target prefix.
      */
 
-    if (isRootEnsemble) {
-	iPtr->ensembleRewrite.sourceObjs = objv;
-	iPtr->ensembleRewrite.numRemovedObjs = 1;
-	iPtr->ensembleRewrite.numInsertedObjs = prefc;
-    } else {
-	iPtr->ensembleRewrite.numInsertedObjs += prefc - 1;
-    }
-
-    /*
-     * We are sending a 0-refCount obj, do not need a callback: it will be
-     * cleaned up automatically. But we may need to clear the rootEnsemble
-     * stuff ...
-     */
-
-    if (isRootEnsemble) {
+    if (TclInitRewriteEnsemble(interp, 1, prefc, objv)) {
 	TclNRAddCallback(interp, TclClearRootEnsemble, NULL, NULL, NULL, NULL);
     }
     TclSkipTailcall(interp);
@@ -1867,7 +1851,7 @@ AliasObjCmd(
     Tcl_Obj **prefv, **cmdv;
     Tcl_Obj *cmdArr[ALIAS_CMDV_PREALLOC];
     Interp *tPtr = (Interp *) targetInterp;
-    int isRootEnsemble = (tPtr->ensembleRewrite.sourceObjs == NULL);
+    int isRootEnsemble;
 
     /*
      * Append the arguments to the command prefix and invoke the command in
@@ -1897,13 +1881,7 @@ AliasObjCmd(
      * only the source command should show, not the full target prefix.
      */
 
-    if (isRootEnsemble) {
-	tPtr->ensembleRewrite.sourceObjs = objv;
-	tPtr->ensembleRewrite.numRemovedObjs = 1;
-	tPtr->ensembleRewrite.numInsertedObjs = prefc;
-    } else {
-	tPtr->ensembleRewrite.numInsertedObjs += prefc - 1;
-    }
+    isRootEnsemble = TclInitRewriteEnsemble((Tcl_Interp *)tPtr, 1, prefc, objv);
 
     /*
      * Protect the target interpreter if it isn't the same as the source
@@ -1926,9 +1904,7 @@ AliasObjCmd(
      */
 
     if (isRootEnsemble) {
-	tPtr->ensembleRewrite.sourceObjs = NULL;
-	tPtr->ensembleRewrite.numRemovedObjs = 0;
-	tPtr->ensembleRewrite.numInsertedObjs = 0;
+	TclResetRewriteEnsemble((Tcl_Interp *)tPtr, 1);
     }
 
     /*
diff --git a/generic/tclOO.c b/generic/tclOO.c
index fd531b7..9dae778 100644
--- a/generic/tclOO.c
+++ b/generic/tclOO.c
@@ -1687,7 +1687,7 @@ Tcl_NewObjectInstance(
 		TclOOGetCallContext(oPtr, NULL, CONSTRUCTOR, NULL);
 
 	if (contextPtr != NULL) {
-	    int result;
+	    int isRoot, result;
 	    Tcl_InterpState state;
 
 	    state = Tcl_SaveInterpState(interp, TCL_OK);
@@ -1698,13 +1698,14 @@ Tcl_NewObjectInstance(
 	     * Adjust the ensmble tracking record if necessary. [Bug 3514761]
 	     */
 
-	    if (((Interp*) interp)->ensembleRewrite.sourceObjs) {
-		((Interp*) interp)->ensembleRewrite.numInsertedObjs += skip-1;
-		((Interp*) interp)->ensembleRewrite.numRemovedObjs += skip-1;
-	    }
+	    isRoot = TclInitRewriteEnsemble(interp, skip, skip, objv);
 	    result = Tcl_NRCallObjProc(interp, TclOOInvokeContext, contextPtr,
 		    objc, objv);
 
+	    if (isRoot) {
+		TclResetRewriteEnsemble(interp, 1);
+	    }
+
 	    /*
 	     * It's an error if the object was whacked in the constructor.
 	     * Force this if it isn't already an error (don't want to lose
@@ -1827,9 +1828,8 @@ TclNRNewObjectInstance(
      * Adjust the ensmble tracking record if necessary. [Bug 3514761]
      */
 
-    if (((Interp *) interp)->ensembleRewrite.sourceObjs) {
-	((Interp *) interp)->ensembleRewrite.numInsertedObjs += skip - 1;
-	((Interp *) interp)->ensembleRewrite.numRemovedObjs += skip - 1;
+    if (TclInitRewriteEnsemble(interp, skip, skip, objv)) {
+	TclNRAddCallback(interp, TclClearRootEnsemble, NULL, NULL, NULL, NULL);
     }
 
     /*
diff --git a/generic/tclOODefineCmds.c b/generic/tclOODefineCmds.c
index c880754..8747ff5 100644
--- a/generic/tclOODefineCmds.c
+++ b/generic/tclOODefineCmds.c
@@ -847,9 +847,8 @@ TclOODefineObjCmd(
 	TclDecrRefCount(objNameObj);
     } else {
 	Tcl_Obj *objPtr, *obj2Ptr, **objs;
-	Interp *iPtr = (Interp *) interp;
 	Tcl_Command cmd;
-	int dummy;
+	int isRoot, dummy;
 
 	/*
 	 * More than one argument: fire them through the ensemble processing
@@ -861,18 +860,7 @@ TclOODefineObjCmd(
 	 * the moment. Ugly!
 	 */
 
-	if (iPtr->ensembleRewrite.sourceObjs == NULL) {
-	    iPtr->ensembleRewrite.sourceObjs = objv;
-	    iPtr->ensembleRewrite.numRemovedObjs = 3;
-	    iPtr->ensembleRewrite.numInsertedObjs = 1;
-	} else {
-	    int ni = iPtr->ensembleRewrite.numInsertedObjs;
-	    if (ni < 3) {
-		iPtr->ensembleRewrite.numRemovedObjs += 3 - ni;
-	    } else {
-		iPtr->ensembleRewrite.numInsertedObjs -= 2;
-	    }
-	}
+	isRoot = TclInitRewriteEnsemble(interp, 3, 1, objv);
 
 	/*
 	 * Build the list of arguments using a Tcl_Obj as a workspace. See
@@ -894,6 +882,9 @@ TclOODefineObjCmd(
 	Tcl_ListObjGetElements(NULL, objPtr, &dummy, &objs);
 
 	result = Tcl_EvalObjv(interp, objc-2, objs, TCL_EVAL_INVOKE);
+	if (isRoot) {
+	    TclResetRewriteEnsemble(interp, 1);
+	}
 	Tcl_DecrRefCount(objPtr);
     }
     DelRef(oPtr);
@@ -927,7 +918,7 @@ TclOOObjDefObjCmd(
     Tcl_Obj *const *objv)
 {
     Foundation *fPtr = TclOOGetFoundation(interp);
-    int result;
+    int isRoot, result;
     Object *oPtr;
 
     if (objc < 3) {
@@ -962,7 +953,6 @@ TclOOObjDefObjCmd(
 	TclDecrRefCount(objNameObj);
     } else {
 	Tcl_Obj *objPtr, *obj2Ptr, **objs;
-	Interp *iPtr = (Interp *) interp;
 	Tcl_Command cmd;
 	int dummy;
 
@@ -976,18 +966,7 @@ TclOOObjDefObjCmd(
 	 * the moment. Ugly!
 	 */
 
-	if (iPtr->ensembleRewrite.sourceObjs == NULL) {
-	    iPtr->ensembleRewrite.sourceObjs = objv;
-	    iPtr->ensembleRewrite.numRemovedObjs = 3;
-	    iPtr->ensembleRewrite.numInsertedObjs = 1;
-	} else {
-	    int ni = iPtr->ensembleRewrite.numInsertedObjs;
-	    if (ni < 3) {
-		iPtr->ensembleRewrite.numRemovedObjs += 3 - ni;
-	    } else {
-		iPtr->ensembleRewrite.numInsertedObjs -= 2;
-	    }
-	}
+	isRoot = TclInitRewriteEnsemble(interp, 3, 1, objv);
 
 	/*
 	 * Build the list of arguments using a Tcl_Obj as a workspace. See
@@ -1009,6 +988,10 @@ TclOOObjDefObjCmd(
 	Tcl_ListObjGetElements(NULL, objPtr, &dummy, &objs);
 
 	result = Tcl_EvalObjv(interp, objc-2, objs, TCL_EVAL_INVOKE);
+
+	if (isRoot) {
+	    TclResetRewriteEnsemble(interp, 1);
+	}
 	Tcl_DecrRefCount(objPtr);
     }
     DelRef(oPtr);
@@ -1077,9 +1060,8 @@ TclOODefineSelfObjCmd(
 	TclDecrRefCount(objNameObj);
     } else {
 	Tcl_Obj *objPtr, *obj2Ptr, **objs;
-	Interp *iPtr = (Interp *) interp;
 	Tcl_Command cmd;
-	int dummy;
+	int isRoot, dummy;
 
 	/*
 	 * More than one argument: fire them through the ensemble processing
@@ -1091,18 +1073,7 @@ TclOODefineSelfObjCmd(
 	 * the moment. Ugly!
 	 */
 
-	if (iPtr->ensembleRewrite.sourceObjs == NULL) {
-	    iPtr->ensembleRewrite.sourceObjs = objv;
-	    iPtr->ensembleRewrite.numRemovedObjs = 2;
-	    iPtr->ensembleRewrite.numInsertedObjs = 1;
-	} else {
-	    int ni = iPtr->ensembleRewrite.numInsertedObjs;
-	    if (ni < 2) {
-		iPtr->ensembleRewrite.numRemovedObjs += 2 - ni;
-	    } else {
-		iPtr->ensembleRewrite.numInsertedObjs -= 1;
-	    }
-	}
+	isRoot = TclInitRewriteEnsemble(interp, 2, 1, objv);
 
 	/*
 	 * Build the list of arguments using a Tcl_Obj as a workspace. See
@@ -1124,6 +1095,9 @@ TclOODefineSelfObjCmd(
 	Tcl_ListObjGetElements(NULL, objPtr, &dummy, &objs);
 
 	result = Tcl_EvalObjv(interp, objc-1, objs, TCL_EVAL_INVOKE);
+	if (isRoot) {
+	    TclResetRewriteEnsemble(interp, 1);
+	}
 	Tcl_DecrRefCount(objPtr);
     }
     DelRef(oPtr);
diff --git a/generic/tclOOMethod.c b/generic/tclOOMethod.c
index 34fa108..a311ddb 100644
--- a/generic/tclOOMethod.c
+++ b/generic/tclOOMethod.c
@@ -1458,6 +1458,11 @@ InvokeForwardMethod(
     argObjs = InitEnsembleRewrite(interp, objc, objv, skip,
 	    numPrefixes, prefixObjs, &len);
     Tcl_NRAddCallback(interp, FinalizeForwardCall, argObjs, NULL, NULL, NULL);
+    /*
+     * NOTE: The combination of direct set of iPtr->lookupNsPtr and the use
+     * of the TCL_EVAL_NOERR flag results in an evaluation configuration
+     * very much like TCL_EVAL_INVOKE.
+     */
     ((Interp *)interp)->lookupNsPtr
 	    = (Namespace *) contextPtr->oPtr->namespacePtr;
     return TclNREvalObjv(interp, len, argObjs, TCL_EVAL_NOERR, NULL);
@@ -1594,12 +1599,9 @@ InitEnsembleRewrite(
     int *lengthPtr)		/* Where to write the resulting length of the
 				 * array of rewritten arguments. */
 {
-    Interp *iPtr = (Interp *) interp;
-    int isRootEnsemble = (iPtr->ensembleRewrite.sourceObjs == NULL);
-    Tcl_Obj **argObjs;
     unsigned len = rewriteLength + objc - toRewrite;
+    Tcl_Obj **argObjs = TclStackAlloc(interp, sizeof(Tcl_Obj *) * len);
 
-    argObjs = TclStackAlloc(interp, sizeof(Tcl_Obj *) * len);
     memcpy(argObjs, rewriteObjs, rewriteLength * sizeof(Tcl_Obj *));
     memcpy(argObjs + rewriteLength, objv + toRewrite,
 	    sizeof(Tcl_Obj *) * (objc - toRewrite));
@@ -1613,22 +1615,9 @@ InitEnsembleRewrite(
      * (and unavoidably).
      */
 
-    if (isRootEnsemble) {
-	iPtr->ensembleRewrite.sourceObjs = objv;
-	iPtr->ensembleRewrite.numRemovedObjs = toRewrite;
-	iPtr->ensembleRewrite.numInsertedObjs = rewriteLength;
-    } else {
-	int numIns = iPtr->ensembleRewrite.numInsertedObjs;
-
-	if (numIns < toRewrite) {
-	    iPtr->ensembleRewrite.numRemovedObjs += toRewrite - numIns;
-	    iPtr->ensembleRewrite.numInsertedObjs += rewriteLength - 1;
-	} else {
-	    iPtr->ensembleRewrite.numInsertedObjs +=
-		    rewriteLength - toRewrite;
-	}
+    if (TclInitRewriteEnsemble(interp, toRewrite, rewriteLength, objv)) {
+	TclNRAddCallback(interp, TclClearRootEnsemble, NULL, NULL, NULL, NULL);
     }
-
     *lengthPtr = len;
     return argObjs;
 }
diff --git a/generic/tclParse.c b/generic/tclParse.c
index 95abc45..568024b 100644
--- a/generic/tclParse.c
+++ b/generic/tclParse.c
@@ -167,6 +167,8 @@ static int		ParseTokens(const char *src, int numBytes, int mask,
 			    int flags, Tcl_Parse *parsePtr);
 static int		ParseWhiteSpace(const char *src, int numBytes,
 			    int *incompletePtr, char *typePtr);
+static int		ParseAllWhiteSpace(const char *src, int numBytes,
+			    int *incompletePtr);
 
 /*
  *----------------------------------------------------------------------
@@ -298,9 +300,43 @@ Tcl_ParseCommand(
      */
 
     parsePtr->commandStart = src;
+    type = CHAR_TYPE(*src);
+    scanned = 1;	/* Can't have missing whitepsace before first word. */
     while (1) {
 	int expandWord = 0;
 
+	/* Are we at command termination? */
+
+	if ((numBytes == 0) || (type & terminators) != 0) {
+	    parsePtr->term = src;
+	    parsePtr->commandSize = src + (numBytes != 0)
+		    - parsePtr->commandStart;
+	    return TCL_OK;
+	}
+
+	/* Are we missing white space after previous word? */
+
+	if (scanned == 0) {
+	    if (src[-1] == '"') {
+		if (interp != NULL) {
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "extra characters after close-quote", -1));
+		}
+		parsePtr->errorType = TCL_PARSE_QUOTE_EXTRA;
+	    } else {
+		if (interp != NULL) {
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "extra characters after close-brace", -1));
+		}
+		parsePtr->errorType = TCL_PARSE_BRACE_EXTRA;
+	    }
+	    parsePtr->term = src;
+	error:
+	    Tcl_FreeParse(parsePtr);
+	    parsePtr->commandSize = parsePtr->end - parsePtr->commandStart;
+	    return TCL_ERROR;
+	}
+
 	/*
 	 * Create the token for the word.
 	 */
@@ -310,23 +346,6 @@ Tcl_ParseCommand(
 	tokenPtr = &parsePtr->tokenPtr[wordIndex];
 	tokenPtr->type = TCL_TOKEN_WORD;
 
-	/*
-	 * Skip white space before the word. Also skip a backslash-newline
-	 * sequence: it should be treated just like white space.
-	 */
-
-	scanned = ParseWhiteSpace(src,numBytes, &parsePtr->incomplete, &type);
-	src += scanned;
-	numBytes -= scanned;
-	if (numBytes == 0) {
-	    parsePtr->term = src;
-	    break;
-	}
-	if ((type & terminators) != 0) {
-	    parsePtr->term = src;
-	    src++;
-	    break;
-	}
 	tokenPtr->start = src;
 	parsePtr->numTokens++;
 	parsePtr->numWords++;
@@ -546,52 +565,12 @@ Tcl_ParseCommand(
 	    tokenPtr->type = TCL_TOKEN_SIMPLE_WORD;
 	}
 
-	/*
-	 * Do two additional checks: (a) make sure we're really at the end of
-	 * a word (there might have been garbage left after a quoted or braced
-	 * word), and (b) check for the end of the command.
-	 */
+	/* Parse the whitespace between words. */
 
 	scanned = ParseWhiteSpace(src,numBytes, &parsePtr->incomplete, &type);
-	if (scanned) {
-	    src += scanned;
-	    numBytes -= scanned;
-	    continue;
-	}
-
-	if (numBytes == 0) {
-	    parsePtr->term = src;
-	    break;
-	}
-	if ((type & terminators) != 0) {
-	    parsePtr->term = src;
-	    src++;
-	    break;
-	}
-	if (src[-1] == '"') {
-	    if (interp != NULL) {
-		Tcl_SetObjResult(interp, Tcl_NewStringObj(
-			"extra characters after close-quote", -1));
-	    }
-	    parsePtr->errorType = TCL_PARSE_QUOTE_EXTRA;
-	} else {
-	    if (interp != NULL) {
-		Tcl_SetObjResult(interp, Tcl_NewStringObj(
-			"extra characters after close-brace", -1));
-	    }
-	    parsePtr->errorType = TCL_PARSE_BRACE_EXTRA;
-	}
-	parsePtr->term = src;
-	goto error;
+	src += scanned;
+	numBytes -= scanned;
     }
-
-    parsePtr->commandSize = src - parsePtr->commandStart;
-    return TCL_OK;
-
-  error:
-    Tcl_FreeParse(parsePtr);
-    parsePtr->commandSize = parsePtr->end - parsePtr->commandStart;
-    return TCL_ERROR;
 }
 
 /*
@@ -733,23 +712,32 @@ ParseWhiteSpace(
  *----------------------------------------------------------------------
  */
 
-int
-TclParseAllWhiteSpace(
+static int
+ParseAllWhiteSpace(
     const char *src,		/* First character to parse. */
-    int numBytes)		/* Max number of byes to scan */
+    int numBytes,		/* Max number of byes to scan */
+    int *incompletePtr)		/* Set true if parse is incomplete. */
 {
-    int dummy;
     char type;
     const char *p = src;
 
     do {
-	int scanned = ParseWhiteSpace(p, numBytes, &dummy, &type);
+	int scanned = ParseWhiteSpace(p, numBytes, incompletePtr, &type);
 
 	p += scanned;
 	numBytes -= scanned;
     } while (numBytes && (*p == '\n') && (p++, --numBytes));
     return (p-src);
 }
+
+int
+TclParseAllWhiteSpace(
+    const char *src,		/* First character to parse. */
+    int numBytes)		/* Max number of byes to scan */
+{
+    int dummy;
+    return ParseAllWhiteSpace(src, numBytes, &dummy);
+}
 
 /*
  *----------------------------------------------------------------------
@@ -1021,17 +1009,12 @@ ParseComment(
 				 * command. */
 {
     register const char *p = src;
+    int incomplete = parsePtr->incomplete;
 
     while (numBytes) {
-	char type;
-	int scanned;
-
-	do {
-	    scanned = ParseWhiteSpace(p, numBytes,
-		    &parsePtr->incomplete, &type);
-	    p += scanned;
-	    numBytes -= scanned;
-	} while (numBytes && (*p == '\n') && (p++,numBytes--));
+	int scanned = ParseAllWhiteSpace(p, numBytes, &incomplete);
+	p += scanned;
+	numBytes -= scanned;
 
 	if ((numBytes == 0) || (*p != '#')) {
 	    break;
@@ -1039,36 +1022,29 @@ ParseComment(
 	if (parsePtr->commentStart == NULL) {
 	    parsePtr->commentStart = p;
 	}
-
+	
+	p++;
+	numBytes--;
 	while (numBytes) {
+	    if (*p == '\n') {
+		p++;
+		numBytes--;
+		break;
+	    }
 	    if (*p == '\\') {
-		scanned = ParseWhiteSpace(p, numBytes, &parsePtr->incomplete,
-			&type);
-		if (scanned) {
-		    p += scanned;
-		    numBytes -= scanned;
-		} else {
-		    /*
-		     * General backslash substitution in comments isn't part
-		     * of the formal spec, but test parse-15.47 and history
-		     * indicate that it has been the de facto rule. Don't
-		     * change it now.
-		     */
-
-		    TclParseBackslash(p, numBytes, &scanned, NULL);
-		    p += scanned;
-		    numBytes -= scanned;
-		}
-	    } else {
 		p++;
 		numBytes--;
-		if (p[-1] == '\n') {
+		if (numBytes == 0) {
 		    break;
 		}
 	    }
+	    incomplete = (*p == '\n');
+	    p++;
+	    numBytes--;
 	}
 	parsePtr->commentSize = p - parsePtr->commentStart;
     }
+    parsePtr->incomplete = incomplete;
     return (p - src);
 }
 
diff --git a/generic/tclPkg.c b/generic/tclPkg.c
index 0a3aef9..d4467e7 100644
--- a/generic/tclPkg.c
+++ b/generic/tclPkg.c
@@ -1913,7 +1913,7 @@ Tcl_PkgInitStubsCheck(
 {
     const char *actualVersion = Tcl_PkgPresent(interp, "Tcl", version, 0);
 
-    if (exact && actualVersion) {
+    if ((exact&1) && actualVersion) {
 	const char *p = version;
 	int count = 0;
 
diff --git a/generic/tclProc.c b/generic/tclProc.c
index 172b860..b663caf 100644
--- a/generic/tclProc.c
+++ b/generic/tclProc.c
@@ -22,7 +22,6 @@
  */
 
 typedef struct {
-    int isRootEnsemble;
     Command cmd;
     ExtraFrameInfo efi;
 } ApplyExtraData;
@@ -870,7 +869,7 @@ TclObjGetFrame(
     }
 
     Tcl_SetObjResult(interp, Tcl_ObjPrintf("bad level \"%s\"", name));
-    Tcl_SetErrorCode(interp, "TCL", "VALUE", "STACKLEVEL", NULL);
+    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LEVEL", name, NULL);
     return -1;
 }
 
@@ -2634,7 +2633,7 @@ TclNRApplyObjCmd(
     Interp *iPtr = (Interp *) interp;
     Proc *procPtr = NULL;
     Tcl_Obj *lambdaPtr, *nsObjPtr;
-    int result, isRootEnsemble;
+    int result;
     Tcl_Namespace *nsPtr;
     ApplyExtraData *extraPtr;
 
@@ -2717,15 +2716,9 @@ TclNRApplyObjCmd(
     extraPtr->efi.fields[0].clientData = lambdaPtr;
     extraPtr->cmd.clientData = &extraPtr->efi;
 
-    isRootEnsemble = (iPtr->ensembleRewrite.sourceObjs == NULL);
-    if (isRootEnsemble) {
-	iPtr->ensembleRewrite.sourceObjs = objv;
-	iPtr->ensembleRewrite.numRemovedObjs = 1;
-	iPtr->ensembleRewrite.numInsertedObjs = 0;
-    } else {
-	iPtr->ensembleRewrite.numInsertedObjs -= 1;
+    if (TclInitRewriteEnsemble(interp, 1, 0, objv)) {
+	TclNRAddCallback(interp, TclClearRootEnsemble, NULL, NULL, NULL, NULL);
     }
-    extraPtr->isRootEnsemble = isRootEnsemble;
 
     result = TclPushProcCallFrame(procPtr, interp, objc, objv, 1);
     if (result == TCL_OK) {
@@ -2743,10 +2736,6 @@ ApplyNR2(
 {
     ApplyExtraData *extraPtr = data[0];
 
-    if (extraPtr->isRootEnsemble) {
-	((Interp *) interp)->ensembleRewrite.sourceObjs = NULL;
-    }
-
     TclStackFree(interp, extraPtr);
     return result;
 }
diff --git a/generic/tclStubLib.c b/generic/tclStubLib.c
index 859cbf9..afabdca 100644
--- a/generic/tclStubLib.c
+++ b/generic/tclStubLib.c
@@ -24,13 +24,10 @@ const TclIntStubs *tclIntStubsPtr = NULL;
 const TclIntPlatStubs *tclIntPlatStubsPtr = NULL;
 
 /*
- * Use our own isDigit to avoid linking to libc on windows
+ * Use our own ISDIGIT to avoid linking to libc on windows
  */
 
-static int isDigit(const int c)
-{
-    return (c >= '0' && c <= '9');
-}
+#define ISDIGIT(c) (((unsigned)((c)-'0')) <= 9)
 
 /*
  *----------------------------------------------------------------------
@@ -54,7 +51,8 @@ MODULE_SCOPE const char *
 Tcl_InitStubs(
     Tcl_Interp *interp,
     const char *version,
-    int exact)
+    int exact,
+    int magic)
 {
     Interp *iPtr = (Interp *) interp;
     const char *actualVersion = NULL;
@@ -67,8 +65,8 @@ Tcl_InitStubs(
      * times. [Bug 615304]
      */
 
-    if (!stubsPtr || (stubsPtr->magic != TCL_STUB_MAGIC)) {
-	iPtr->result = "interpreter uses an incompatible stubs mechanism";
+    if (!stubsPtr || (stubsPtr->magic != (((exact&0xff00) >= 0x900) ? magic : TCL_STUB_MAGIC))) {
+	iPtr->result = (char *)"interpreter uses an incompatible stubs mechanism";
 	iPtr->freeProc = TCL_STATIC;
 	return NULL;
     }
@@ -77,12 +75,12 @@ Tcl_InitStubs(
     if (actualVersion == NULL) {
 	return NULL;
     }
-    if (exact) {
+    if (exact&1) {
 	const char *p = version;
 	int count = 0;
 
 	while (*p) {
-	    count += !isDigit(*p++);
+	    count += !ISDIGIT(*p++);
 	}
 	if (count == 1) {
 	    const char *q = actualVersion;
@@ -91,7 +89,7 @@ Tcl_InitStubs(
 	    while (*p && (*p == *q)) {
 		p++; q++;
 	    }
-	    if (*p || isDigit(*q)) {
+	    if (*p || ISDIGIT(*q)) {
 		/* Construct error message */
 		stubsPtr->tcl_PkgRequireEx(interp, "Tcl", version, 1, NULL);
 		return NULL;
diff --git a/generic/tclUtil.c b/generic/tclUtil.c
index 2b0fb72..553593c 100644
--- a/generic/tclUtil.c
+++ b/generic/tclUtil.c
@@ -2634,7 +2634,19 @@ Tcl_DStringAppend(
 	    memcpy(newString, dsPtr->string, (size_t) dsPtr->length);
 	    dsPtr->string = newString;
 	} else {
+	    int offset = -1;
+
+	    /* See [16896d49fd] */
+	    if (bytes >= dsPtr->string
+		    && bytes <= dsPtr->string + dsPtr->length) {
+		offset = bytes - dsPtr->string;
+	    }
+
 	    dsPtr->string = ckrealloc(dsPtr->string, dsPtr->spaceAvl);
+
+	    if (offset >= 0) {
+		bytes = dsPtr->string + offset;
+	    }
 	}
     }
 
@@ -2725,7 +2737,19 @@ Tcl_DStringAppendElement(
 	    memcpy(newString, dsPtr->string, (size_t) dsPtr->length);
 	    dsPtr->string = newString;
 	} else {
+	    int offset = -1;
+
+	    /* See [16896d49fd] */
+	    if (element >= dsPtr->string
+		    && element <= dsPtr->string + dsPtr->length) {
+		offset = element - dsPtr->string;
+	    }
+
 	    dsPtr->string = ckrealloc(dsPtr->string, dsPtr->spaceAvl);
+
+	    if (offset >= 0) {
+		element = dsPtr->string + offset;
+	    }
 	}
 	dst = dsPtr->string + dsPtr->length;
     }
diff --git a/generic/tclVar.c b/generic/tclVar.c
index b5b5b10..dc7fa20 100644
--- a/generic/tclVar.c
+++ b/generic/tclVar.c
@@ -4921,7 +4921,8 @@ Tcl_UpvarObjCmd(
 
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 		"bad level \"%s\"", TclGetString(levelObj)));
-	Tcl_SetErrorCode(interp, "TCL", "VALUE", "LEVEL", NULL);
+	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LEVEL",
+		TclGetString(levelObj), NULL);
 	return TCL_ERROR;
     }
 
diff --git a/generic/tclZlib.c b/generic/tclZlib.c
index 691d57a..dac47cf 100644
--- a/generic/tclZlib.c
+++ b/generic/tclZlib.c
@@ -2906,9 +2906,9 @@ ZlibTransformClose(
 		}
 	    }
 	} while (e != Z_STREAM_END);
-	e = deflateEnd(&cd->outStream);
+	(void) deflateEnd(&cd->outStream);
     } else {
-	e = inflateEnd(&cd->inStream);
+	(void) inflateEnd(&cd->inStream);
     }
 
     /*
@@ -3344,10 +3344,13 @@ ZlibTransformGetOption(
 		Tcl_DStringAppendElement(dsPtr, "");
 	    }
 	} else {
-	    int len;
-	    const char *str = Tcl_GetStringFromObj(cd->compDictObj, &len);
+	    if (cd->compDictObj) {
+		int len;
+		const char *str = Tcl_GetStringFromObj(cd->compDictObj, &len);
 
-	    Tcl_DStringAppend(dsPtr, str, len);
+		Tcl_DStringAppend(dsPtr, str, len);
+	    }
+	    return TCL_OK;
 	}
     }
 
@@ -3549,7 +3552,6 @@ ZlibStackChannelTransform(
     ZlibChannelData *cd = ckalloc(sizeof(ZlibChannelData));
     Tcl_Channel chan;
     int wbits = 0;
-    int e;
 
     if (mode != TCL_ZLIB_STREAM_DEFLATE && mode != TCL_ZLIB_STREAM_INFLATE) {
 	Tcl_Panic("unknown mode: %d", mode);
@@ -3603,43 +3605,35 @@ ZlibStackChannelTransform(
      */
 
     if (mode == TCL_ZLIB_STREAM_INFLATE) {
-	e = inflateInit2(&cd->inStream, wbits);
-	if (e != Z_OK) {
+	if (inflateInit2(&cd->inStream, wbits) != Z_OK) {
 	    goto error;
 	}
 	cd->inAllocated = DEFAULT_BUFFER_SIZE;
 	cd->inBuffer = ckalloc(cd->inAllocated);
 	if (cd->flags & IN_HEADER) {
-	    e = inflateGetHeader(&cd->inStream, &cd->inHeader.header);
-	    if (e != Z_OK) {
+	    if (inflateGetHeader(&cd->inStream, &cd->inHeader.header) != Z_OK) {
 		goto error;
 	    }
 	}
 	if (cd->format == TCL_ZLIB_FORMAT_RAW && cd->compDictObj) {
-	    e = SetInflateDictionary(&cd->inStream, cd->compDictObj);
-	    if (e != Z_OK) {
+	    if (SetInflateDictionary(&cd->inStream, cd->compDictObj) != Z_OK) {
 		goto error;
 	    }
-	    TclDecrRefCount(cd->compDictObj);
-	    cd->compDictObj = NULL;
 	}
     } else {
-	e = deflateInit2(&cd->outStream, level, Z_DEFLATED, wbits,
-		MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
-	if (e != Z_OK) {
+	if (deflateInit2(&cd->outStream, level, Z_DEFLATED, wbits,
+		MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK) {
 	    goto error;
 	}
 	cd->outAllocated = DEFAULT_BUFFER_SIZE;
 	cd->outBuffer = ckalloc(cd->outAllocated);
 	if (cd->flags & OUT_HEADER) {
-	    e = deflateSetHeader(&cd->outStream, &cd->outHeader.header);
-	    if (e != Z_OK) {
+	    if (deflateSetHeader(&cd->outStream, &cd->outHeader.header) != Z_OK) {
 		goto error;
 	    }
 	}
 	if (cd->compDictObj) {
-	    e = SetDeflateDictionary(&cd->outStream, cd->compDictObj);
-	    if (e != Z_OK) {
+	    if (SetDeflateDictionary(&cd->outStream, cd->compDictObj) != Z_OK) {
 		goto error;
 	    }
 	}
diff --git a/tests/dict.test b/tests/dict.test
index d5406d0..a6b0cb4 100644
--- a/tests/dict.test
+++ b/tests/dict.test
@@ -2048,6 +2048,13 @@ test dict-24.25 {dict map with huge dict (compiled)} {
     }} 100000
 } 166666666600000
 
+test dict-25.1 {compiled dict update with low-refcount values [Bug d553228d9f]} {
+    # Test crashes on failure
+    apply {{} {
+	lassign {} item
+	dict update item item item two two {}
+    }}
+} {}
 
 # cleanup
 ::tcltest::cleanupTests
diff --git a/tests/namespace.test b/tests/namespace.test
index 5c5783b..fc74d73 100644
--- a/tests/namespace.test
+++ b/tests/namespace.test
@@ -2928,6 +2928,22 @@ test namespace-53.10 {ensembles: nested rewrite} -setup {
     0 {1 v}\
     1 {wrong # args: should be "ns v x z2 a2"}\
     0 {2 v v2}}
+test namespace-53.11 {ensembles: nested rewrite} -setup {
+    namespace eval ns {
+	namespace export x
+	namespace eval x {
+	    proc z2 {a1 a2} {list 2 $a1 $a2}
+	    namespace export z*
+	    namespace ensemble create -parameter p
+	}
+	namespace ensemble create
+    }
+} -body {
+    list [catch {ns x 1 z2} msg] $msg
+} -cleanup {
+    namespace delete ns
+    unset -nocomplain msg
+} -result {1 {wrong # args: should be "ns x 1 z2 a2"}}
 
 test namespace-54.1 {leak on namespace deletion} -constraints {memory} \
 -setup {
diff --git a/tests/zlib.test b/tests/zlib.test
index 968469d..c9e5f10 100644
--- a/tests/zlib.test
+++ b/tests/zlib.test
@@ -401,6 +401,26 @@ test zlib-8.16 {Bug 3603553: buffer transfer with large writes} -setup {
 } -cleanup {
     removeFile $file
 } -result 57647
+test zlib-8.17 {Bug dd260aaf: fconfigure} -setup {
+    lassign [chan pipe] inSide outSide
+} -constraints zlib -body {
+    zlib push inflate $inSide
+    zlib push deflate $outSide
+    list [chan configure $inSide -dictionary] [chan configure $outSide -dictionary]
+} -cleanup {
+    catch {close $inSide}
+    catch {close $outSide}
+} -result {{} {}}
+test zlib-8.18 {Bug dd260aaf: fconfigure} -setup {
+    lassign [chan pipe] inSide outSide
+} -constraints zlib -body {
+    zlib push inflate $inSide -dictionary "one two"
+    zlib push deflate $outSide -dictionary "one two"
+    list [chan configure $inSide -dictionary] [chan configure $outSide -dictionary]
+} -cleanup {
+    catch {close $inSide}
+    catch {close $outSide}
+} -result {{one two} {one two}}
 
 test zlib-9.1 "check fcopy with push" -constraints zlib -setup {
     set sfile [makeFile {} testsrc.gz]
diff --git a/unix/configure b/unix/configure
index 0f83eec..9ee8336 100755
--- a/unix/configure
+++ b/unix/configure
@@ -761,6 +761,7 @@ enable_shared
 enable_64bit
 enable_64bit_vis
 enable_rpath
+with_dbgx
 enable_corefoundation
 enable_load
 enable_symbols
@@ -1416,6 +1417,7 @@ Optional Packages:
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
   --with-encoding         encoding for configuration values (default:
                           iso8859-1)
+  --with-dbgx             debug extension for binaries
   --with-tzdata           install timezone data (default: autodetect)
 
 Some influential environment variables:
@@ -4969,6 +4971,13 @@ fi
 
     # Step 3: set configuration options based on system name and version.
 
+
+# Check whether --with-dbgx was given.
+if test "${with_dbgx+set}" = set; then :
+  withval=$with_dbgx; with_dbgx=${withval}
+fi
+
+
     do64bit_ok=no
     # default to '{$LIBS}' and set to "" on per-platform necessary basis
     SHLIB_LD_LIBS='${LIBS}'
@@ -5260,7 +5269,7 @@ fi
 	    CC_SEARCH_FLAGS=""
 	    LD_SEARCH_FLAGS=""
 	    TCL_NEEDS_EXP_FILE=1
-	    TCL_EXPORT_FILE_SUFFIX='${VERSION}\$\{DBGX\}.dll.a'
+	    TCL_EXPORT_FILE_SUFFIX='${VERSION}${with_dbgx}.dll.a'
 	    SHLIB_LD_LIBS="${SHLIB_LD_LIBS} -Wl,--out-implib,\$@.a"
 	    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for Cygwin version of gcc" >&5
 $as_echo_n "checking for Cygwin version of gcc... " >&6; }
@@ -5771,7 +5780,7 @@ fi
 		    CC_SEARCH_FLAGS='-Wl,-rpath,${LIB_RUNTIME_DIR}'
 fi
 		LD_SEARCH_FLAGS=${CC_SEARCH_FLAGS}
-		SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.so.${SHLIB_VERSION}'
+		SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.so.${SHLIB_VERSION}'
 		LDFLAGS="-Wl,-export-dynamic"
 		;;
 	    esac
@@ -5795,7 +5804,7 @@ fi
 
 fi
 	    # OpenBSD doesn't do version numbers with dots.
-	    UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.a'
+	    UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.a'
 	    ;;
 	NetBSD-*)
 	    # NetBSD has ELF and can use 'cc -shared' to build shared libs
@@ -5843,8 +5852,8 @@ fi
 	    case $system in
 	    FreeBSD-3.*)
 		# Version numbers are dot-stripped by system policy.
-		UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.a'
-		SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.so'
+		UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.a'
+		SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.so'
 		;;
 	    esac
 	    ;;
@@ -6317,8 +6326,8 @@ fi
 	    # requires an extra version number at the end of .so file names.
 	    # So, the library has to have a name like libtcl75.so.1.0
 
-	    SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.so.${SHLIB_VERSION}'
-	    UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.a'
+	    SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.so.${SHLIB_VERSION}'
+	    UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.a'
 	    ;;
 	SunOS-5.[0-6])
 	    # Careful to not let 5.10+ fall into this case
@@ -6649,11 +6658,11 @@ fi
 
     if test "$SHARED_LIB_SUFFIX" = ""; then :
 
-	SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${SHLIB_SUFFIX}'
+	SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}${SHLIB_SUFFIX}'
 fi
     if test "$UNSHARED_LIB_SUFFIX" = ""; then :
 
-	UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.a'
+	UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.a'
 fi
     DLL_INSTALL_DIR="\$(LIB_INSTALL_DIR)"
 
@@ -6801,7 +6810,6 @@ else
 fi
 
 # FIXME: Currently, LDFLAGS_DEFAULT is not used, it should work like CFLAGS_DEFAULT.
-    DBGX=""
     if test "$tcl_ok" = "no"; then
 	CFLAGS_DEFAULT='$(CFLAGS_OPTIMIZE)'
 	LDFLAGS_DEFAULT='$(LDFLAGS_OPTIMIZE)'
@@ -10361,7 +10369,7 @@ else
     eval libdir="$libdir"
     # default install directory for bundled packages
     PACKAGE_DIR="$libdir"
-    TCL_LIB_FLAG="-ltcl${TCL_MAJOR_VERSION}"
+    TCL_LIB_FLAG="-ltcl${TCL_MAJOR_VERSION}${with_dbgx}"
     TCL_BUILD_LIB_SPEC="-L`pwd | sed -e 's/ /\\\\ /g'` ${TCL_LIB_FLAG}"
     TCL_LIB_SPEC="-L${libdir} ${TCL_LIB_FLAG}"
 fi
@@ -10399,7 +10407,7 @@ eval "TCL_STUB_LIB_FILE=libtclstub${TCL_UNSHARED_LIB_SUFFIX}"
 eval "TCL_STUB_LIB_FILE=\"${TCL_STUB_LIB_FILE}\""
 eval "TCL_STUB_LIB_DIR=${libdir}"
 
-TCL_STUB_LIB_FLAG="-ltclstub${TCL_MAJOR_VERSION}"
+TCL_STUB_LIB_FLAG="-ltclstub${TCL_MAJOR_VERSION}${with_dbgx}"
 
 TCL_BUILD_STUB_LIB_SPEC="-L`pwd | sed -e 's/ /\\\\ /g'` ${TCL_STUB_LIB_FLAG}"
 TCL_STUB_LIB_SPEC="-L${TCL_STUB_LIB_DIR} ${TCL_STUB_LIB_FLAG}"
diff --git a/unix/configure.ac b/unix/configure.ac
index 13a497c..676bc8b 100644
--- a/unix/configure.ac
+++ b/unix/configure.ac
@@ -860,7 +860,7 @@ else
     eval libdir="$libdir"
     # default install directory for bundled packages
     PACKAGE_DIR="$libdir"
-    TCL_LIB_FLAG="-ltcl${TCL_MAJOR_VERSION}"
+    TCL_LIB_FLAG="-ltcl${TCL_MAJOR_VERSION}${with_dbgx}"
     TCL_BUILD_LIB_SPEC="-L`pwd | sed -e 's/ /\\\\ /g'` ${TCL_LIB_FLAG}"
     TCL_LIB_SPEC="-L${libdir} ${TCL_LIB_FLAG}"
 fi
@@ -898,7 +898,7 @@ eval "TCL_STUB_LIB_FILE=libtclstub${TCL_UNSHARED_LIB_SUFFIX}"
 eval "TCL_STUB_LIB_FILE=\"${TCL_STUB_LIB_FILE}\""
 eval "TCL_STUB_LIB_DIR=${libdir}"
 
-TCL_STUB_LIB_FLAG="-ltclstub${TCL_MAJOR_VERSION}"
+TCL_STUB_LIB_FLAG="-ltclstub${TCL_MAJOR_VERSION}${with_dbgx}"
 
 TCL_BUILD_STUB_LIB_SPEC="-L`pwd | sed -e 's/ /\\\\ /g'` ${TCL_STUB_LIB_FLAG}"
 TCL_STUB_LIB_SPEC="-L${TCL_STUB_LIB_DIR} ${TCL_STUB_LIB_FLAG}"
diff --git a/unix/installManPage b/unix/installManPage
index 4d615bf..1f1cbde 100755
--- a/unix/installManPage
+++ b/unix/installManPage
@@ -106,7 +106,7 @@ for Target in $Names; do
 	First=$Target
 	sed -e "/man\.macros/r $SrcDir/man.macros" -e "/man\.macros/d" \
 	    $ManPage > $Dir/$First
-	chmod 444 $Dir/$First
+	chmod 644 $Dir/$First
 	$Gzip $Dir/$First
     else
 	ln $SymOrLoc$First$Gz $Dir/$Target$Gz
diff --git a/unix/tcl.m4 b/unix/tcl.m4
index 5ae523b..87d9b9b 100644
--- a/unix/tcl.m4
+++ b/unix/tcl.m4
@@ -737,7 +737,6 @@ AC_DEFUN([SC_ENABLE_SYMBOLS], [
 	    [build with debugging symbols (default: off)]),
 	[tcl_ok=$enableval], [tcl_ok=no])
 # FIXME: Currently, LDFLAGS_DEFAULT is not used, it should work like CFLAGS_DEFAULT.
-    DBGX=""
     if test "$tcl_ok" = "no"; then
 	CFLAGS_DEFAULT='$(CFLAGS_OPTIMIZE)'
 	LDFLAGS_DEFAULT='$(LDFLAGS_OPTIMIZE)'
@@ -1081,6 +1080,8 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 
     # Step 3: set configuration options based on system name and version.
 
+    AC_ARG_WITH(dbgx, [  --with-dbgx             debug extension for binaries], with_dbgx=${withval})
+
     do64bit_ok=no
     # default to '{$LIBS}' and set to "" on per-platform necessary basis
     SHLIB_LD_LIBS='${LIBS}'
@@ -1214,7 +1215,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    CC_SEARCH_FLAGS=""
 	    LD_SEARCH_FLAGS=""
 	    TCL_NEEDS_EXP_FILE=1
-	    TCL_EXPORT_FILE_SUFFIX='${VERSION}\$\{DBGX\}.dll.a'
+	    TCL_EXPORT_FILE_SUFFIX='${VERSION}${with_dbgx}.dll.a'
 	    SHLIB_LD_LIBS="${SHLIB_LD_LIBS} -Wl,--out-implib,\$[@].a"
 	    AC_CACHE_CHECK(for Cygwin version of gcc,
 		ac_cv_cygwin,
@@ -1488,7 +1489,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 		AS_IF([test $doRpath = yes], [
 		    CC_SEARCH_FLAGS='-Wl,-rpath,${LIB_RUNTIME_DIR}'])
 		LD_SEARCH_FLAGS=${CC_SEARCH_FLAGS}
-		SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.so.${SHLIB_VERSION}'
+		SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.so.${SHLIB_VERSION}'
 		LDFLAGS="-Wl,-export-dynamic"
 		;;
 	    esac
@@ -1510,7 +1511,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 		CFLAGS="$CFLAGS -pthread"
 	    ])
 	    # OpenBSD doesn't do version numbers with dots.
-	    UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.a'
+	    UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.a'
 	    ;;
 	NetBSD-*)
 	    # NetBSD has ELF and can use 'cc -shared' to build shared libs
@@ -1550,8 +1551,8 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    case $system in
 	    FreeBSD-3.*)
 		# Version numbers are dot-stripped by system policy.
-		UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.a'
-		SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.so'
+		UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.a'
+		SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.so'
 		;;
 	    esac
 	    ;;
@@ -1820,8 +1821,8 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    # requires an extra version number at the end of .so file names.
 	    # So, the library has to have a name like libtcl75.so.1.0
 
-	    SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.so.${SHLIB_VERSION}'
-	    UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.a'
+	    SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.so.${SHLIB_VERSION}'
+	    UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.a'
 	    ;;
 	SunOS-5.[[0-6]])
 	    # Careful to not let 5.10+ fall into this case
@@ -2035,9 +2036,9 @@ dnl # preprocessing tests use only CPPFLAGS.
     ])
 
     AS_IF([test "$SHARED_LIB_SUFFIX" = ""], [
-	SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${SHLIB_SUFFIX}'])
+	SHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}${SHLIB_SUFFIX}'])
     AS_IF([test "$UNSHARED_LIB_SUFFIX" = ""], [
-	UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}.a'])
+	UNSHARED_LIB_SUFFIX='${TCL_MAJOR_VERSION}${with_dbgx}.a'])
     DLL_INSTALL_DIR="\$(LIB_INSTALL_DIR)"
 
     AS_IF([test "${SHARED_BUILD}" = 1 -a "${SHLIB_SUFFIX}" != ""], [
diff --git a/win/Makefile.in b/win/Makefile.in
index ed82ab0..4eac03c 100644
--- a/win/Makefile.in
+++ b/win/Makefile.in
@@ -66,9 +66,6 @@ MAN3_INSTALL_DIR = $(MAN_INSTALL_DIR)/man3
 # Directory in which to install manual entries for the built-in Tcl commands:
 MANN_INSTALL_DIR = $(MAN_INSTALL_DIR)/mann
 
-# Libraries built with optimization switches have this additional extension
-TCL_DBGX = @TCL_DBGX@
-
 # warning flags
 CFLAGS_WARNING = @CFLAGS_WARNING@
 
diff --git a/win/configure b/win/configure
index e8e03e7..e6c5703 100755
--- a/win/configure
+++ b/win/configure
@@ -769,6 +769,7 @@ enable_shared
 enable_64bit
 enable_wince
 with_celib
+with_dbgx
 enable_symbols
 enable_embedded_manifest
 '
@@ -1401,6 +1402,7 @@ Optional Packages:
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
   --with-encoding         encoding for configuration values
   --with-celib=DIR        use Windows/CE support library from DIR
+  --with-dbgx             debug extension for binaries
 
 Some influential environment variables:
   CC          C compiler command
@@ -3882,6 +3884,13 @@ fi
 
 
 
+
+# Check whether --with-dbgx was given.
+if test "${with_dbgx+set}" = set; then :
+  withval=$with_dbgx; with_dbgx=${withval}
+fi
+
+
     SHLIB_SUFFIX=".dll"
 
     # MACHINE is IX86 for LINK, but this is used by the manifest,
@@ -4130,7 +4139,7 @@ $as_echo_n "checking compiler flags... " >&6; }
 $as_echo "using static flags" >&6; }
 	    runtime=
 	    LIBRARIES="\${STATIC_LIBRARIES}"
-	    EXESUFFIX="s\${DBGX}.exe"
+	    EXESUFFIX="${with_dbgx}.exe"
 	else
 	    # dynamic
             { $as_echo "$as_me:${as_lineno-$LINENO}: result: using shared flags" >&5
@@ -4145,7 +4154,7 @@ $as_echo "using shared flags" >&6; }
 	    runtime=
 	    # Add SHLIB_LD_LIBS to the Make rule, not here.
 
-	    EXESUFFIX="\${DBGX}.exe"
+	    EXESUFFIX="${with_dbgx}.exe"
 	    LIBRARIES="\${SHARED_LIBRARIES}"
 	fi
 	# Link with gcc since ld does not link to default libs like
@@ -4156,9 +4165,9 @@ $as_echo "using shared flags" >&6; }
 	    -Wl,--out-implib,\$(patsubst %.dll,lib%.a,\$@)"
 	# DLLSUFFIX is separate because it is the building block for
 	# users of tclConfig.sh that may build shared or static.
-	DLLSUFFIX="\${DBGX}.dll"
-	LIBSUFFIX="\${DBGX}.a"
-	LIBFLAGSUFFIX="\${DBGX}"
+	DLLSUFFIX="${with_dbgx}.dll"
+	LIBSUFFIX="${with_dbgx}.a"
+	LIBFLAGSUFFIX="${with_dbgx}"
 	SHLIB_SUFFIX=.dll
 
 	EXTRA_CFLAGS="${extra_cflags}"
@@ -4239,7 +4248,7 @@ $as_echo "   Using 64-bit $MACHINE mode" >&6; }
 $as_echo "using static flags" >&6; }
 	    runtime=-MT
 	    LIBRARIES="\${STATIC_LIBRARIES}"
-	    EXESUFFIX="s\${DBGX}.exe"
+	    EXESUFFIX="${with_dbgx}.exe"
 	else
 	    # dynamic
             { $as_echo "$as_me:${as_lineno-$LINENO}: result: using shared flags" >&5
@@ -4247,7 +4256,7 @@ $as_echo "using shared flags" >&6; }
 	    runtime=-MD
 	    # Add SHLIB_LD_LIBS to the Make rule, not here.
 	    LIBRARIES="\${SHARED_LIBRARIES}"
-	    EXESUFFIX="\${DBGX}.exe"
+	    EXESUFFIX="${with_dbgx}.exe"
 	    case "x`echo \${VisualStudioVersion}`" in
 		x1[4-9]*)
 		    lflags="${lflags} -nodefaultlib:libucrt.lib"
@@ -4259,9 +4268,9 @@ $as_echo "using shared flags" >&6; }
 	MAKE_DLL="\${SHLIB_LD} \$(LDFLAGS) -out:\$@"
 	# DLLSUFFIX is separate because it is the building block for
 	# users of tclConfig.sh that may build shared or static.
-	DLLSUFFIX="\${DBGX}.dll"
-	LIBSUFFIX="\${DBGX}.lib"
-	LIBFLAGSUFFIX="\${DBGX}"
+	DLLSUFFIX="${with_dbgx}.dll"
+	LIBSUFFIX="${with_dbgx}.lib"
+	LIBFLAGSUFFIX="${with_dbgx}"
 
 	# This is a 2-stage check to make sure we have the 64-bit SDK
 	# We have to know where the SDK is installed.
@@ -5015,7 +5024,6 @@ fi
     if test "$tcl_ok" = "no"; then
 	CFLAGS_DEFAULT='$(CFLAGS_OPTIMIZE)'
 	LDFLAGS_DEFAULT='$(LDFLAGS_OPTIMIZE)'
-	DBGX=""
 
 $as_echo "#define NDEBUG 1" >>confdefs.h
 
@@ -5027,7 +5035,6 @@ $as_echo "no" >&6; }
     else
 	CFLAGS_DEFAULT='$(CFLAGS_DEBUG)'
 	LDFLAGS_DEFAULT='$(LDFLAGS_DEBUG)'
-	DBGX=g
 	if test "$tcl_ok" = "yes"; then
 	    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes (standard debugging)" >&5
 $as_echo "yes (standard debugging)" >&6; }
@@ -5062,7 +5069,7 @@ $as_echo "enabled $tcl_ok debugging" >&6; }
     fi
 
 
-TCL_DBGX=${DBGX}
+TCL_DBGX=""
 
 #--------------------------------------------------------------------
 # Embed the manifest if we can determine how
@@ -5167,17 +5174,9 @@ CFG_TCL_EXPORT_FILE_SUFFIX=${TCL_EXPORT_FILE_SUFFIX}
 #--------------------------------------------------------------------
 
 if test ${SHARED_BUILD} = 0 ; then
-    if test "${DBGX}" = "g"; then
-        RC_DEFINES="${RC_DEFINE} STATIC_BUILD ${RC_DEFINE} DEBUG"
-    else
-        RC_DEFINES="${RC_DEFINE} STATIC_BUILD"
-    fi
+    RC_DEFINES="${RC_DEFINE} STATIC_BUILD"
 else
-    if test "${DBGX}" = "g"; then
-        RC_DEFINES="${RC_DEFINE} DEBUG"
-    else
-        RC_DEFINES=""
-    fi
+    RC_DEFINES=""
 fi
 
 #--------------------------------------------------------------------
diff --git a/win/configure.ac b/win/configure.ac
index 1646aaa..84df590 100644
--- a/win/configure.ac
+++ b/win/configure.ac
@@ -4,7 +4,7 @@
 # to configure the system for the local environment.
 
 AC_INIT(../generic/tcl.h)
-AC_PREREQ(2.59)
+AC_PREREQ(2.69)
 
 # The following define is needed when building with Cygwin since newer
 # versions of autoconf incorrectly set SHELL to /bin/bash instead of
@@ -268,7 +268,7 @@ fi
 
 SC_ENABLE_SYMBOLS
 
-TCL_DBGX=${DBGX}
+TCL_DBGX=""
 
 #--------------------------------------------------------------------
 # Embed the manifest if we can determine how
@@ -324,17 +324,9 @@ CFG_TCL_EXPORT_FILE_SUFFIX=${TCL_EXPORT_FILE_SUFFIX}
 #--------------------------------------------------------------------
 
 if test ${SHARED_BUILD} = 0 ; then
-    if test "${DBGX}" = "g"; then
-        RC_DEFINES="${RC_DEFINE} STATIC_BUILD ${RC_DEFINE} DEBUG"
-    else
-        RC_DEFINES="${RC_DEFINE} STATIC_BUILD"
-    fi
+    RC_DEFINES="${RC_DEFINE} STATIC_BUILD"
 else
-    if test "${DBGX}" = "g"; then
-        RC_DEFINES="${RC_DEFINE} DEBUG"
-    else
-        RC_DEFINES=""
-    fi
+    RC_DEFINES=""
 fi
 
 #--------------------------------------------------------------------
diff --git a/win/tcl.m4 b/win/tcl.m4
index 7dfbd73..91c9465 100644
--- a/win/tcl.m4
+++ b/win/tcl.m4
@@ -442,7 +442,6 @@ AC_DEFUN([SC_ENABLE_THREADS], [
 #				Sets to $(CFLAGS_OPTIMIZE) if false
 #		LDFLAGS_DEFAULT	Sets to $(LDFLAGS_DEBUG) if true
 #				Sets to $(LDFLAGS_OPTIMIZE) if false
-#		DBGX		Debug library extension
 #
 #------------------------------------------------------------------------
 
@@ -453,7 +452,6 @@ AC_DEFUN([SC_ENABLE_SYMBOLS], [
     if test "$tcl_ok" = "no"; then
 	CFLAGS_DEFAULT='$(CFLAGS_OPTIMIZE)'
 	LDFLAGS_DEFAULT='$(LDFLAGS_OPTIMIZE)'
-	DBGX=""
 	AC_DEFINE(NDEBUG, 1, [Is no debugging enabled?])
 	AC_MSG_RESULT([no])
 
@@ -461,7 +459,6 @@ AC_DEFUN([SC_ENABLE_SYMBOLS], [
     else
 	CFLAGS_DEFAULT='$(CFLAGS_DEBUG)'
 	LDFLAGS_DEFAULT='$(LDFLAGS_DEBUG)'
-	DBGX=g
 	if test "$tcl_ok" = "yes"; then
 	    AC_MSG_RESULT([yes (standard debugging)])
 	fi
@@ -561,6 +558,8 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 
     AC_CHECK_PROG(CYGPATH, cygpath, cygpath -m, echo)
 
+    AC_ARG_WITH(dbgx, [  --with-dbgx             debug extension for binaries], with_dbgx=${withval})
+
     SHLIB_SUFFIX=".dll"
 
     # MACHINE is IX86 for LINK, but this is used by the manifest,
@@ -693,7 +692,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
             AC_MSG_RESULT([using static flags])
 	    runtime=
 	    LIBRARIES="\${STATIC_LIBRARIES}"
-	    EXESUFFIX="s\${DBGX}.exe"
+	    EXESUFFIX="${with_dbgx}.exe"
 	else
 	    # dynamic
             AC_MSG_RESULT([using shared flags])
@@ -707,7 +706,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    runtime=
 	    # Add SHLIB_LD_LIBS to the Make rule, not here.
 
-	    EXESUFFIX="\${DBGX}.exe"
+	    EXESUFFIX="${with_dbgx}.exe"
 	    LIBRARIES="\${SHARED_LIBRARIES}"
 	fi
 	# Link with gcc since ld does not link to default libs like
@@ -718,9 +717,9 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    -Wl,--out-implib,\$(patsubst %.dll,lib%.a,\[$]@)"
 	# DLLSUFFIX is separate because it is the building block for
 	# users of tclConfig.sh that may build shared or static.
-	DLLSUFFIX="\${DBGX}.dll"
-	LIBSUFFIX="\${DBGX}.a"
-	LIBFLAGSUFFIX="\${DBGX}"
+	DLLSUFFIX="${with_dbgx}.dll"
+	LIBSUFFIX="${with_dbgx}.a"
+	LIBFLAGSUFFIX="${with_dbgx}"
 	SHLIB_SUFFIX=.dll
 
 	EXTRA_CFLAGS="${extra_cflags}"
@@ -783,14 +782,14 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
             AC_MSG_RESULT([using static flags])
 	    runtime=-MT
 	    LIBRARIES="\${STATIC_LIBRARIES}"
-	    EXESUFFIX="s\${DBGX}.exe"
+	    EXESUFFIX="${with_dbgx}.exe"
 	else
 	    # dynamic
             AC_MSG_RESULT([using shared flags])
 	    runtime=-MD
 	    # Add SHLIB_LD_LIBS to the Make rule, not here.
 	    LIBRARIES="\${SHARED_LIBRARIES}"
-	    EXESUFFIX="\${DBGX}.exe"
+	    EXESUFFIX="${with_dbgx}.exe"
 	    case "x`echo \${VisualStudioVersion}`" in
 		x1[[4-9]]*)
 		    lflags="${lflags} -nodefaultlib:libucrt.lib"
@@ -802,9 +801,9 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	MAKE_DLL="\${SHLIB_LD} \$(LDFLAGS) -out:\[$]@"
 	# DLLSUFFIX is separate because it is the building block for
 	# users of tclConfig.sh that may build shared or static.
-	DLLSUFFIX="\${DBGX}.dll"
-	LIBSUFFIX="\${DBGX}.lib"
-	LIBFLAGSUFFIX="\${DBGX}"
+	DLLSUFFIX="${with_dbgx}.dll"
+	LIBSUFFIX="${with_dbgx}.lib"
+	LIBFLAGSUFFIX="${with_dbgx}"
 
 	# This is a 2-stage check to make sure we have the 64-bit SDK
 	# We have to know where the SDK is installed.
@@ -1213,7 +1212,7 @@ AC_DEFUN([SC_PROG_TCLSH], [
 
 AC_DEFUN([SC_BUILD_TCLSH], [
     AC_MSG_CHECKING([for tclsh in Tcl build directory])
-    BUILD_TCLSH=${TCL_BIN_DIR}/tclsh${TCL_MAJOR_VERSION}${TCL_MINOR_VERSION}${TCL_DBGX}${EXEEXT}
+    BUILD_TCLSH=${TCL_BIN_DIR}/tclsh${TCL_MAJOR_VERSION}${TCL_MINOR_VERSION}${EXEEXT}
     AC_MSG_RESULT($BUILD_TCLSH)
     AC_SUBST(BUILD_TCLSH)
 ])