Patch 976520 reworks several of the details involved with

        startup/initialization of the Tcl library, focused on the
        activities of Tcl_FindExecutable().

        * generic/tclIO.c:      Removed bogus claim in comment that
        encoding "iso8859-1" is "built-in" to Tcl.

        * generic/tclInt.h:     Created a new struct ProcessGlobalValue,
        * generic/tclUtil.c:    routines Tcl(Get|Set)ProcessGlobalValue,
        and function type TclInitProcessGlobalValueProc.  Together, these
        take care of the housekeeping for "values" (things that can be
        held in a Tcl_Obj) that are global across a whole process.  That is,
        they are shared among multiple threads, and epoch and mutex
        protection must govern the validity of cached copies maintained
        in each thread.

        * generic/tclNotify.c:  Modified TclInitNotifier() to tolerate
        being called multiple times in the same thread.

        * generic/tclEvent.c:   Dropped the unused argv0 argument to
        TclInitSubsystems().  Removed machinery to unsure only one
        TclInitNotifier() call per thread, now that that is safe.
        Converted Tcl(Get|Set)LibraryPath to use a ProcessGlobalValue,
        and moved them to tclEncoding.c.
        * generic/tclBasic.c:   Updated caller.

        * generic/tclInt.h:     TclpFindExecutable now returns void.
        * unix/tclUnixFile.c:
        * win/tclWinFile.c:
        * win/tclWinPipe.c:

        * generic/tclEncoding.c: Built new encoding search initialization
        on a foundation of ProcessGlobalValues, exposing new routines
        Tcl(Get|Set)EncodingSearchPath.  A cache of a map from encoding name
        to directory pathname keeps track of where encodings are available
        for loading.  Tcl_FindExecutable greatly simplified into just
        three function calls.  The "library path" is now misnamed, as its
        only remaining purpose is as a foundation for the default encoding
        search path.

        * generic/tclInterp.c:  Inlined the initScript that is evaluated
        by Tcl_Init().  Added verification after initScript evaluation
        that Tcl can find its installed *.enc files, and that it has
        initialized [encoding system] in agreement with what the environment
        expects.  [tclInit] no longer driven by the value of $::tcl_libPath;
        it largely constructs its own search path now, rather than attempt
        to share one with the encoding system.

        * unix/tclUnixInit.c:   TclpSetInitialEncodings factored so that a new
        * win/tclWinInit.c:     routine TclpGetEncodingNameFromEnvironment
        can reveal that Tcl thinks the [encoding system] should be, even
        when an incomplete encoding search path, or a missing *.enc file
        won't allow that initialization to succeed.  TclpInitLibraryPath
        reworked as an initializer of a ProcessGlobalValue.

        * unix/tclUnixTest.c:   Update implementations of [testfindexecutable],
        [testgetdefenc], and [testsetdefenc].

        * tests/unixInit.test:  Corrected tests to operate properly even
        when a value of TCL_LIBRARY is required to find encodings.

        * generic/tclInt.decls: New internal stubs: TclGetEncodingSearchPath,
        TclSetEncodingSearchPath, TclpGetEncodingNameFromEnvironment.  These
        are candidates for public exposure by future TIPs.

        * generic/tclIntDecls.h:        make genstubs
        * generic/tclStubInit.c:

        * generic/tclTest.c:    Updated [testencoding] to use
        * tests/encoding.test:  Tcl(Get|Set)EncodingSearchPath.  Updated tests.

1 files changed, 172 insertions, 105 deletions

diff --git a/generic/tclInterp.c b/generic/tclInterp.c
index 194944b..d1cd7f5 100644
--- a/generic/tclInterp.c
+++ b/generic/tclInterp.c
@@ -10,116 +10,13 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclInterp.c,v 1.52 2004/11/22 21:24:30 dgp Exp $
+ * RCS: @(#) $Id: tclInterp.c,v 1.53 2004/11/30 19:34:49 dgp Exp $
  */
 
 #include "tclInt.h"
 #include <stdio.h>
 
 /*
- * In order to find init.tcl during initialization, the following script
- * is invoked by Tcl_Init().  It looks in several different directories:
- *
- *	$tcl_library		- can specify a primary location, if set,
- *				  no other locations will be checked.  This
- *				  is the recommended way for a program that
- *				  embeds Tcl to specifically tell Tcl where
- *				  to find an init.tcl file.
- *
- *	$env(TCL_LIBRARY)	- highest priority so user can always override
- *				  the search path unless the application has
- *				  specified an exact directory above
- *
- *	$tclDefaultLibrary	- INTERNAL:  This variable is set by Tcl
- *				  on those platforms where it can determine
- *				  at runtime the directory where it expects
- *				  the init.tcl file to be.  After [tclInit]
- *				  reads and uses this value, it [unset]s it.
- *				  External users of Tcl should not make use
- *				  of the variable to customize [tclInit].
- *
- *	$tcl_libPath		- OBSOLETE:  This variable is no longer
- *				  set by Tcl itself, but [tclInit] examines
- *				  it in case some program that embeds Tcl
- *				  is customizing [tclInit] by setting this
- *				  variable to a list of directories in which
- *				  to search.
- *
- *      [tcl::pkgconfig get scriptdir,runtime]
- *      			- the directory determined by configure to 
- *      			  be the place where Tcl's script library
- *      			  is to be installed. 
- *
- * The first directory on this path that contains a valid init.tcl script
- * will be set as the value of tcl_library.
- *
- * Note that this entire search mechanism can be bypassed by defining an
- * alternate tclInit procedure before calling Tcl_Init().
- */
-
-static char initScript[] = "if {[info proc tclInit]==\"\"} {\n\
-  proc tclInit {} {\n\
-    global tcl_libPath tcl_library\n\
-    global env tclDefaultLibrary\n\
-    variable ::tcl::LibPath\n\
-    rename tclInit {}\n\
-    set errors {}\n\
-    set LibPath {}\n\
-    if {[info exists tcl_library]} {\n\
-	lappend LibPath $tcl_library\n\
-    } else {\n\
-	if {[info exists env(TCL_LIBRARY)]} {\n\
-	    lappend LibPath $env(TCL_LIBRARY)\n\
-	    if {[regexp ^tcl(.*)$ [file tail $env(TCL_LIBRARY)] -> tail]} {\n\
-		if {$tail ne [info tclversion]} {\n\
-		    lappend LibPath [file join [file dirname\\\n\
-			    $env(TCL_LIBRARY)] tcl[info tclversion]]\n\
-		}\n\
-	    }\n\
-	}\n\
-	if {[catch {\n\
-	    lappend LibPath $tclDefaultLibrary\n\
-	    unset tclDefaultLibrary\n\
-	}]} {\n\
-	    lappend LibPath [::tcl::pkgconfig get scriptdir,runtime]\n\
-	}\n\
-	set parentDir [file normalize [file dirname [file dirname\\\n\
-		[info nameofexecutable]]]]\n\
-	set grandParentDir [file dirname $parentDir]\n\
-	lappend LibPath [file join $parentDir lib tcl[info tclversion]]\n\
-	lappend LibPath [file join $grandParentDir lib tcl[info tclversion]]\n\
-	lappend LibPath [file join $parentDir library]\n\
-	lappend LibPath [file join $grandParentDir library]\n\
-	lappend LibPath [file join $grandParentDir\\\n\
-       		tcl[info patchlevel] library]\n\
-	lappend LibPath [file join [file dirname $grandParentDir]\\\n\
-       		tcl[info patchlevel] library]\n\
-	catch {\n\
-            set LibPath [concat $LibPath $tcl_libPath]\n\
-	}\n\
-    }\n\
-    foreach i $LibPath {\n\
-	set tcl_library $i\n\
-	set tclfile [file join $i init.tcl]\n\
-	if {[file exists $tclfile]} {\n\
-	    if {![catch {uplevel #0 [list source $tclfile]} msg opts]} {\n\
-		return\n\
-	    } else {\n\
-		append errors \"$tclfile: $msg\n\"\n\
-		append errors \"[dict get $opts -errorinfo]\n\"\n\
-	    }\n\
-	}\n\
-    }\n\
-    set msg \"Can't find a usable init.tcl in the following directories: \n\"\n\
-    append msg \"    $LibPath\n\n\"\n\
-    append msg \"$errors\n\n\"\n\
-    append msg \"This probably means that Tcl wasn't installed properly.\n\"\n\
-    error $msg\n\
-  }\n\
-}\n\
-tclInit";
-
-/*
  * A pointer to a string that holds an initialization script that if non-NULL
  * is evaluated in Tcl_Init() prior to the built-in initialization script
  * above.  This variable can be modified by the procedure below.
@@ -404,12 +301,182 @@ int
 Tcl_Init(interp)
     Tcl_Interp *interp;         /* Interpreter to initialize. */
 {
+    int code;
+    Tcl_DString script, encodingName;
+    Tcl_Obj *path;
+
     if (tclPreInitScript != NULL) {
 	if (Tcl_Eval(interp, tclPreInitScript) == TCL_ERROR) {
 	    return (TCL_ERROR);
 	};
     }
-    return Tcl_Eval(interp, initScript);
+/*
+ * In order to find init.tcl during initialization, the following script
+ * is invoked by Tcl_Init().  It looks in several different directories:
+ *
+ *	$tcl_library		- can specify a primary location, if set,
+ *				  no other locations will be checked.  This
+ *				  is the recommended way for a program that
+ *				  embeds Tcl to specifically tell Tcl where
+ *				  to find an init.tcl file.
+ *
+ *	$env(TCL_LIBRARY)	- highest priority so user can always override
+ *				  the search path unless the application has
+ *				  specified an exact directory above
+ *
+ *	$tclDefaultLibrary	- INTERNAL:  This variable is set by Tcl
+ *				  on those platforms where it can determine
+ *				  at runtime the directory where it expects
+ *				  the init.tcl file to be.  After [tclInit]
+ *				  reads and uses this value, it [unset]s it.
+ *				  External users of Tcl should not make use
+ *				  of the variable to customize [tclInit].
+ *
+ *	$tcl_libPath		- OBSOLETE:  This variable is no longer
+ *				  set by Tcl itself, but [tclInit] examines
+ *				  it in case some program that embeds Tcl
+ *				  is customizing [tclInit] by setting this
+ *				  variable to a list of directories in which
+ *				  to search.
+ *
+ *      [tcl::pkgconfig get scriptdir,runtime]
+ *      			- the directory determined by configure to 
+ *      			  be the place where Tcl's script library
+ *      			  is to be installed. 
+ *
+ * The first directory on this path that contains a valid init.tcl script
+ * will be set as the value of tcl_library.
+ *
+ * Note that this entire search mechanism can be bypassed by defining an
+ * alternate tclInit procedure before calling Tcl_Init().
+ */
+    code = Tcl_Eval(interp,
+"if {[info proc tclInit]==\"\"} {\n"
+"  proc tclInit {} {\n"
+"    global tcl_libPath tcl_library\n"
+"    global env tclDefaultLibrary\n"
+"    variable ::tcl::LibPath\n"
+"    rename tclInit {}\n"
+"    set errors {}\n"
+"    set localPath {}\n"
+"    set LibPath {}\n"
+"    if {[info exists tcl_library]} {\n"
+"	lappend localPath $tcl_library\n"
+"    } else {\n"
+"	if {[info exists env(TCL_LIBRARY)]\n"
+"		&& [string length $env(TCL_LIBRARY)]} {\n"
+"	    lappend localPath $env(TCL_LIBRARY)\n"
+"	    lappend LibPath $env(TCL_LIBRARY)\n"
+"	    if {[regexp ^tcl(.*)$ [file tail $env(TCL_LIBRARY)] -> tail]} {\n"
+"		if {$tail ne [info tclversion]} {\n"
+"		    lappend localPath [file join [file dirname\\\n"
+"			    $env(TCL_LIBRARY)] tcl[info tclversion]]\n"
+"		    lappend LibPath [file join [file dirname\\\n"
+"			    $env(TCL_LIBRARY)] tcl[info tclversion]]\n"
+"		}\n"
+"	    }\n"
+"	}\n"
+"	if {[catch {\n"
+"	    lappend localPath $tclDefaultLibrary\n"
+"	    unset tclDefaultLibrary\n"
+"	}]} {\n"
+"	    lappend localPath [::tcl::pkgconfig get scriptdir,runtime]\n"
+"	}\n"
+"	set parentDir [file normalize [file dirname [file dirname\\\n"
+"		[info nameofexecutable]]]]\n"
+"	set grandParentDir [file dirname $parentDir]\n"
+"	lappend LibPath [file join $parentDir lib tcl[info tclversion]]\n"
+"	lappend LibPath [file join $grandParentDir lib tcl[info tclversion]]\n"
+"	lappend LibPath [file join $parentDir library]\n"
+"	lappend LibPath [file join $grandParentDir library]\n"
+"	lappend LibPath [file join $grandParentDir\\\n"
+"       		tcl[info patchlevel] library]\n"
+"	lappend LibPath [file join [file dirname $grandParentDir]\\\n"
+"       		tcl[info patchlevel] library]\n"
+"	catch {\n"
+"            set LibPath [concat $LibPath $tcl_libPath]\n"
+"	}\n"
+"    }\n"
+"    foreach i [concat $localPath $LibPath] {\n"
+"	set tcl_library $i\n"
+"	set tclfile [file join $i init.tcl]\n"
+"	if {[file exists $tclfile]} {\n"
+"	    if {![catch {uplevel #0 [list source $tclfile]} msg opts]} {\n"
+"		return\n"
+"	    } else {\n"
+"		append errors \"$tclfile: $msg\n\"\n"
+"		append errors \"[dict get $opts -errorinfo]\n\"\n"
+"	    }\n"
+"	}\n"
+"    }\n"
+"    set msg \"Can't find a usable init.tcl in the following directories: \n\"\n"
+"    append msg \"    $localPath $LibPath\n\n\"\n"
+"    append msg \"$errors\n\n\"\n"
+"    append msg \"This probably means that Tcl wasn't installed properly.\n\"\n"
+"    error $msg\n"
+"  }\n"
+"}\n"
+"tclInit");
+
+    if (code != TCL_OK) {
+	return code;
+    }
+
+    /* 
+     * Now that [info library] is initialized, make sure that
+     * [file join [info library] encoding] is on the encoding
+     * search path.
+     *
+     * Relying on use of original built-in commands.
+     * Should be a safe assumption during interp initialization.
+     * More robust would be to use C-coded equivalents, but that's such
+     * a pain...
+     */
+
+    Tcl_DStringInit(&script);
+    Tcl_DStringAppend(&script, "lsearch -exact", -1);
+    path = Tcl_DuplicateObj(TclGetEncodingSearchPath());
+    Tcl_IncrRefCount(path);
+    Tcl_DStringAppendElement(&script, Tcl_GetString(path));
+    Tcl_DStringAppend(&script, " [file join [info library] encoding]", -1);
+    code = Tcl_EvalEx(interp, Tcl_DStringValue(&script),
+	    Tcl_DStringLength(&script), TCL_EVAL_GLOBAL);
+    Tcl_DStringFree(&script);
+    if (code == TCL_OK) {
+	int index;
+	Tcl_GetIntFromObj(interp, Tcl_GetObjResult(interp), &index);
+	if (index != -1) {
+	    /* [info library]/encoding already on the encoding search path */
+	    goto done;
+	}
+    }
+    Tcl_DStringInit(&script);
+    Tcl_DStringAppend(&script, "file join [info library] encoding", -1);
+    code = Tcl_EvalEx(interp, Tcl_DStringValue(&script),
+	    Tcl_DStringLength(&script), TCL_EVAL_GLOBAL);
+    Tcl_DStringFree(&script);
+    if (code == TCL_OK) {
+	Tcl_ListObjAppendElement(NULL, path, Tcl_GetObjResult(interp));
+	TclSetEncodingSearchPath(path);
+    }
+done:
+    /*
+     * Now that we know the distributed *.enc files are on the encoding
+     * search path, check whether the [encoding system] matches that
+     * specified by the environment, and if not, attempt to correct it
+     */
+    TclpGetEncodingNameFromEnvironment(&encodingName);
+    if (strcmp(Tcl_DStringValue(&encodingName), Tcl_GetEncodingName(NULL))) {
+	code = Tcl_SetSystemEncoding(NULL, Tcl_DStringValue(&encodingName));
+	if (code == TCL_ERROR) {
+	    Tcl_Panic("system encoding \"", Tcl_DStringValue(&encodingName),
+		    "\" not available");
+	}
+    }
+    Tcl_DStringFree(&encodingName);
+    Tcl_DecrRefCount(path);
+    Tcl_ResetResult(interp);
+    return TCL_OK;
 }
 
 /*