merge 8.6

5 files changed, 302 insertions, 190 deletions

diff --git a/generic/tclCmdMZ.c b/generic/tclCmdMZ.c
index ba96d7c..3c5c5e4 100644
--- a/generic/tclCmdMZ.c
+++ b/generic/tclCmdMZ.c
@@ -3228,8 +3228,7 @@ StringTrimCmd(
     }
     string1 = TclGetStringFromObj(objv[1], &length1);
 
-    triml = TclTrimLeft(string1, length1, string2, length2);
-    trimr = TclTrimRight(string1 + triml, length1 - triml, string2, length2);
+    triml = TclTrim(string1, length1, string2, length2, &trimr);
 
     Tcl_SetObjResult(interp,
 	    Tcl_NewStringObj(string1 + triml, length1 - triml - trimr));
diff --git a/generic/tclInt.h b/generic/tclInt.h
index e7794c7..57f648c 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -3198,6 +3198,8 @@ MODULE_SCOPE void	TclSubstParse(Tcl_Interp *interp, const char *bytes,
 MODULE_SCOPE int	TclSubstTokens(Tcl_Interp *interp, Tcl_Token *tokenPtr,
 			    int count, int *tokensLeftPtr, int line,
 			    int *clNextOuter, const char *outerScript);
+MODULE_SCOPE int	TclTrim(const char *bytes, int numBytes,
+			    const char *trim, int numTrim, int *trimRight);
 MODULE_SCOPE int	TclTrimLeft(const char *bytes, int numBytes,
 			    const char *trim, int numTrim);
 MODULE_SCOPE int	TclTrimRight(const char *bytes, int numBytes,
diff --git a/generic/tclOO.c b/generic/tclOO.c
index dcf48ef..c80f039 100644
--- a/generic/tclOO.c
+++ b/generic/tclOO.c
@@ -523,47 +523,47 @@ InitClassSystemRoots(
 
     fakeCls.thisPtr = &fakeObject;
 
+
     fPtr->objectCls = AllocClass(interp,
 	    AllocObject(interp, "object", (Namespace *)fPtr->ooNs, NULL));
-    fPtr->classCls = AllocClass(interp,
-	    AllocObject(interp, "class", (Namespace *)fPtr->ooNs, NULL));
-
-    /*
-     * Rewire bootstrapped objects.
-     */
-
-    fPtr->objectCls->thisPtr->selfCls = fPtr->classCls;
-    fPtr->classCls->thisPtr->selfCls = fPtr->classCls;
-
+    /* Corresponding TclOODecrRefCount in KillFoudation */
     AddRef(fPtr->objectCls->thisPtr);
-    AddRef(fPtr->classCls->thisPtr);
-    AddRef(fPtr->classCls->thisPtr->selfCls->thisPtr);
-    AddRef(fPtr->objectCls->thisPtr->selfCls->thisPtr);
 
-    /*
-     * Special initialization for the primordial objects.
-     */
+    /* This is why it is unnecessary in this routine to replace the
+     * incremented reference count of fPtr->objectCls that was swallowed by
+     * fakeObject. */
+    fPtr->objectCls->superclasses.num = 0;
+    ckfree(fPtr->objectCls->superclasses.list);
+    fPtr->objectCls->superclasses.list = NULL;
 
+    /* special initialization for the primordial objects */
     fPtr->objectCls->thisPtr->flags |= ROOT_OBJECT;
     fPtr->objectCls->flags |= ROOT_OBJECT;
 
+    fPtr->classCls = AllocClass(interp,
+	    AllocObject(interp, "class", (Namespace *)fPtr->ooNs, NULL));
+    /* Corresponding TclOODecrRefCount in KillFoudation */
+    AddRef(fPtr->classCls->thisPtr);
+
     /*
-     * This is why it is unnecessary in this routine to make up for the
-     * incremented reference count of fPtr->objectCls that was sallwed by
-     * fakeObject.
+     * Increment reference counts for each reference because these
+     * relationships can be dynamically changed.
+     *
+     * Corresponding TclOODecrRefCount for all incremented refcounts is in
+     * KillFoundation.
      */
 
-    fPtr->objectCls->superclasses.num = 0;
-    ckfree(fPtr->objectCls->superclasses.list);
-    fPtr->objectCls->superclasses.list = NULL;
+    /* Rewire bootstrapped objects. */
+    fPtr->objectCls->thisPtr->selfCls = fPtr->classCls;
+    AddRef(fPtr->objectCls->thisPtr->selfCls->thisPtr);
+
+    fPtr->classCls->thisPtr->selfCls = fPtr->classCls;
+    AddRef(fPtr->classCls->thisPtr->selfCls->thisPtr);
 
     fPtr->classCls->thisPtr->flags |= ROOT_CLASS;
     fPtr->classCls->flags |= ROOT_CLASS;
 
-    /*
-     * Standard initialization for new Objects.
-     */
-
+    /* Standard initialization for new Objects */
     TclOOAddToInstances(fPtr->objectCls->thisPtr, fPtr->classCls);
     TclOOAddToInstances(fPtr->classCls->thisPtr, fPtr->classCls);
     TclOOAddToSubclasses(fPtr->classCls, fPtr->objectCls);
@@ -632,20 +632,20 @@ KillFoundation(
 {
     Foundation *fPtr = GetFoundation(interp);
 
-    /*
-     * Crude mechanism to avoid leaking the Object struct of the
-     * foundation components oo::object and oo::class
-     *
-     * Should probably be replaced with something more elegantly designed.
-     */
-    while (TclOODecrRefCount(fPtr->objectCls->thisPtr) == 0) {};
-    while (TclOODecrRefCount(fPtr->classCls->thisPtr) == 0) {};
-
     TclDecrRefCount(fPtr->unknownMethodNameObj);
     TclDecrRefCount(fPtr->constructorName);
     TclDecrRefCount(fPtr->destructorName);
     TclDecrRefCount(fPtr->clonedName);
     TclDecrRefCount(fPtr->defineName);
+    if (fPtr->objectCls->thisPtr->selfCls != NULL) {
+	TclOODecrRefCount(fPtr->objectCls->thisPtr->selfCls->thisPtr);
+    }
+    if (fPtr->classCls->thisPtr->selfCls != NULL) {
+	TclOODecrRefCount(fPtr->classCls->thisPtr->selfCls->thisPtr);
+    }
+    TclOODecrRefCount(fPtr->objectCls->thisPtr);
+    TclOODecrRefCount(fPtr->classCls->thisPtr);
+
     ckfree(fPtr);
 }
 
@@ -729,6 +729,8 @@ AllocObject(
 	Tcl_ResetResult(interp);
     }
 
+    ((Namespace *)oPtr->namespacePtr)->refCount++;
+
     /*
      * Make the namespace know about the helper commands. This grants access
      * to the [self] and [next] commands.
@@ -901,10 +903,9 @@ ObjectRenamedTrace(
 /*
  * ----------------------------------------------------------------------
  *
- * DeleteDescendants, ReleaseClassContents --
+ * DeleteDescendants --
  *
- *	Tear down the special class data structure, including deleting all
- *	dependent classes and objects.
+ *	Delete all descendants of a particular class.
  *
  * ----------------------------------------------------------------------
  */
@@ -916,44 +917,55 @@ DeleteDescendants(
 {
     Class *clsPtr = oPtr->classPtr, *subclassPtr, *mixinSubclassPtr;
     Object *instancePtr;
-    int i;
 
     /*
      * Squelch classes that this class has been mixed into.
      */
 
-    FOREACH(mixinSubclassPtr, clsPtr->mixinSubs) {
-	/*
-	 * This condition also covers the case where mixinSubclassPtr ==
-	 * clsPtr
-	 */
-
-	if (!Deleted(mixinSubclassPtr->thisPtr)) {
-	    Tcl_DeleteCommandFromToken(interp,
-		    mixinSubclassPtr->thisPtr->command);
+    if (clsPtr->mixinSubs.num > 0) {
+	while (clsPtr->mixinSubs.num > 0) {
+	    mixinSubclassPtr = clsPtr->mixinSubs.list[clsPtr->mixinSubs.num-1];
+	    /* This condition also covers the case where mixinSubclassPtr ==
+	     * clsPtr
+	     */
+	    if (!Deleted(mixinSubclassPtr->thisPtr)) {
+		Tcl_DeleteCommandFromToken(interp,
+			mixinSubclassPtr->thisPtr->command);
+	    }
+	    TclOORemoveFromMixinSubs(mixinSubclassPtr, clsPtr);
 	}
-	i -= TclOORemoveFromMixinSubs(mixinSubclassPtr, clsPtr);
-	TclOODecrRefCount(mixinSubclassPtr->thisPtr);
+    }
+    if (clsPtr->mixinSubs.size > 0) {
+	ckfree(clsPtr->mixinSubs.list);
+	clsPtr->mixinSubs.size = 0;
     }
 
     /*
      * Squelch subclasses of this class.
      */
 
-    FOREACH(subclassPtr, clsPtr->subclasses) {
-	if (!Deleted(subclassPtr->thisPtr) && !IsRoot(subclassPtr)) {
-	    Tcl_DeleteCommandFromToken(interp, subclassPtr->thisPtr->command);
+    if (clsPtr->subclasses.num > 0) {
+	while (clsPtr->subclasses.num > 0) {
+	    subclassPtr = clsPtr->subclasses.list[clsPtr->subclasses.num-1];
+	    if (!Deleted(subclassPtr->thisPtr) && !IsRoot(subclassPtr)) {
+		Tcl_DeleteCommandFromToken(interp, subclassPtr->thisPtr->command);
+	    }
+	    TclOORemoveFromSubclasses(subclassPtr, clsPtr);
 	}
-	i -= TclOORemoveFromSubclasses(subclassPtr, clsPtr);
-	TclOODecrRefCount(subclassPtr->thisPtr);
+    }
+    if (clsPtr->subclasses.size > 0) {
+	ckfree(clsPtr->subclasses.list);
+	clsPtr->subclasses.list = NULL;
+	clsPtr->subclasses.size = 0;
     }
 
     /*
      * Squelch instances of this class (includes objects we're mixed into).
      */
 
-    if (!IsRootClass(oPtr)) {
-	FOREACH(instancePtr, clsPtr->instances) {
+    if (clsPtr->instances.num > 0) {
+	while (clsPtr->instances.num > 0) {
+	    instancePtr = clsPtr->instances.list[clsPtr->instances.num-1];
 	    /*
 	     * This condition also covers the case where instancePtr == oPtr
 	     */
@@ -961,10 +973,26 @@ DeleteDescendants(
 	    if (!Deleted(instancePtr) && !IsRoot(instancePtr)) {
 		Tcl_DeleteCommandFromToken(interp, instancePtr->command);
 	    }
-	    i -= TclOORemoveFromInstances(instancePtr, clsPtr);
+	    TclOORemoveFromInstances(instancePtr, clsPtr);
 	}
     }
+    if (clsPtr->instances.size > 0) {
+	ckfree(clsPtr->instances.list);
+	clsPtr->instances.list = NULL;
+	clsPtr->instances.size = 0;
+    }
 }
+
+/*
+ * ----------------------------------------------------------------------
+ *
+ * ReleaseClassContents --
+ *
+ *	Tear down the special class data structure, including deleting all
+ *	dependent classes and objects.
+ *
+ * ----------------------------------------------------------------------
+ */
 
 static void
 ReleaseClassContents(
@@ -1034,21 +1062,6 @@ ReleaseClassContents(
     }
 
     /*
-     * Squelch our instances.
-     */
-
-    if (clsPtr->instances.num) {
-	Object *oPtr;
-
-	FOREACH(oPtr, clsPtr->instances) {
-	    TclOODecrRefCount(oPtr);
-	}
-	ckfree(clsPtr->instances.list);
-	clsPtr->instances.list = NULL;
-	clsPtr->instances.num = 0;
-    }
-
-    /*
      * Squelch our metadata.
      */
 
@@ -1064,11 +1077,21 @@ ReleaseClassContents(
 	clsPtr->metadataPtr = NULL;
     }
 
-    FOREACH(tmpClsPtr, clsPtr->mixins) {
-	TclOORemoveFromMixinSubs(clsPtr, tmpClsPtr);
+    if (clsPtr->mixins.num) {
+	FOREACH(tmpClsPtr, clsPtr->mixins) {
+	    TclOORemoveFromMixinSubs(clsPtr, tmpClsPtr);
+	}
+	ckfree(clsPtr->mixins.list);
     }
-    FOREACH(tmpClsPtr, clsPtr->superclasses) {
-	TclOORemoveFromSubclasses(clsPtr, tmpClsPtr);
+
+    if (clsPtr->superclasses.num > 0) {
+	FOREACH(tmpClsPtr, clsPtr->superclasses) {
+	    TclOORemoveFromSubclasses(clsPtr, tmpClsPtr);
+	    TclOODecrRefCount(tmpClsPtr->thisPtr);
+	}
+	ckfree(clsPtr->superclasses.list);
+	clsPtr->superclasses.num = 0;
+	clsPtr->superclasses.list = NULL;
     }
 
     FOREACH_HASH_VALUE(mPtr, &clsPtr->classMethods) {
@@ -1204,10 +1227,10 @@ ObjectNamespaceDeleted(
 
     TclOORemoveFromInstances(oPtr, oPtr->selfCls);
 
-    FOREACH(mixinPtr, oPtr->mixins) {
-	i -= TclOORemoveFromInstances(oPtr, mixinPtr);
-    }
-    if (i) {
+    if (oPtr->mixins.num > 0) {
+	FOREACH(mixinPtr, oPtr->mixins) {
+	    TclOORemoveFromInstances(oPtr, mixinPtr);
+	}
 	ckfree(oPtr->mixins.list);
     }
 
@@ -1276,7 +1299,9 @@ ObjectNamespaceDeleted(
      * Delete the object structure itself.
      */
 
+    TclNsDecrRefCount((Namespace *)oPtr->namespacePtr);
     oPtr->namespacePtr = NULL;
+    TclOODecrRefCount(oPtr->selfCls->thisPtr);
     oPtr->selfCls = NULL;
     TclOODecrRefCount(oPtr);
     return;
@@ -1299,14 +1324,8 @@ TclOODecrRefCount(
     Object *oPtr)
 {
     if (oPtr->refCount-- <= 1) {
-	Class *clsPtr = oPtr->classPtr;
 
 	if (oPtr->classPtr != NULL) {
-	    ckfree(clsPtr->superclasses.list);
-	    ckfree(clsPtr->subclasses.list);
-	    ckfree(clsPtr->instances.list);
-	    ckfree(clsPtr->mixinSubs.list);
-	    ckfree(clsPtr->mixins.list);
 	    ckfree(oPtr->classPtr);
 	}
 	ckfree(oPtr);
@@ -1335,10 +1354,6 @@ TclOORemoveFromInstances(
     int i, res = 0;
     Object *instPtr;
 
-    if (Deleted(clsPtr->thisPtr)) {
-	return res;
-    }
-
     FOREACH(instPtr, clsPtr->instances) {
 	if (oPtr == instPtr) {
 	    RemoveItem(Object, clsPtr->instances, i);
@@ -1401,10 +1416,6 @@ TclOORemoveFromSubclasses(
     int i, res = 0;
     Class *subclsPtr;
 
-    if (Deleted(superPtr->thisPtr)) {
-	return res;
-    }
-
     FOREACH(subclsPtr, superPtr->subclasses) {
 	if (subPtr == subclsPtr) {
 	    RemoveItem(Class, superPtr->subclasses, i);
@@ -1469,10 +1480,6 @@ TclOORemoveFromMixinSubs(
     int i, res = 0;
     Class *subclsPtr;
 
-    if (Deleted(superPtr->thisPtr)) {
-	return res;
-    }
-
     FOREACH(subclsPtr, superPtr->mixinSubs) {
 	if (subPtr == subclsPtr) {
 	    RemoveItem(Class, superPtr->mixinSubs, i);
@@ -1780,6 +1787,7 @@ TclNewObjectInstanceCommon(
 
     oPtr = AllocObject(interp, simpleName, nsPtr, nsNameStr);
     oPtr->selfCls = classPtr;
+    AddRef(classPtr->thisPtr);
     TclOOAddToInstances(oPtr, classPtr);
 
     /*
@@ -2025,6 +2033,11 @@ Tcl_CopyObjectInstance(
 	cls2Ptr->superclasses.num = clsPtr->superclasses.num;
 	FOREACH(superPtr, cls2Ptr->superclasses) {
 	    TclOOAddToSubclasses(cls2Ptr, superPtr);
+
+	    /* For the new item in cls2Ptr->superclasses that memcpy just
+	     * created
+	     */
+	    AddRef(superPtr->thisPtr);
 	}
 
 	/*
diff --git a/generic/tclOODefineCmds.c b/generic/tclOODefineCmds.c
index 7c2a641..6c1d58a 100644
--- a/generic/tclOODefineCmds.c
+++ b/generic/tclOODefineCmds.c
@@ -1185,15 +1185,13 @@ TclOODefineClassObjCmd(
      */
 
     if (oPtr->selfCls != clsPtr) {
-	TclOORemoveFromInstances(oPtr, oPtr->selfCls);
-
-	/*
-	 * Reference count already incremented a few lines up.
-	 */
 
+	TclOORemoveFromInstances(oPtr, oPtr->selfCls);
+	TclOODecrRefCount(oPtr->selfCls->thisPtr);
 	oPtr->selfCls = clsPtr;
-
+	AddRef(oPtr->selfCls->thisPtr);
 	TclOOAddToInstances(oPtr, oPtr->selfCls);
+
 	if (oPtr->classPtr != NULL) {
 	    BumpGlobalEpoch(interp, oPtr->classPtr);
 	} else {
@@ -2234,11 +2232,6 @@ ClassSuperSet(
 	    superclasses[0] = oPtr->fPtr->objectCls;
 	}
 	superc = 1;
-
-	/*
-	 * Corresponding TclOODecrRefCount is near the end of this function.
-	 */
-
 	AddRef(superclasses[0]->thisPtr);
     } else {
 	for (i=0 ; i<superc ; i++) {
@@ -2295,12 +2288,6 @@ ClassSuperSet(
     oPtr->classPtr->superclasses.num = superc;
     FOREACH(superPtr, oPtr->classPtr->superclasses) {
 	TclOOAddToSubclasses(oPtr->classPtr, superPtr);
-
-	/*
-	 * To account for the AddRef() earlier in this function.
-	 */
-
-	TclOODecrRefCount(superPtr->thisPtr);
     }
     BumpGlobalEpoch(interp, oPtr->classPtr);
 
diff --git a/generic/tclUtil.c b/generic/tclUtil.c
index d1b81a9..3fbc325 100644
--- a/generic/tclUtil.c
+++ b/generic/tclUtil.c
@@ -1647,11 +1647,46 @@ Tcl_Backslash(
 /*
  *----------------------------------------------------------------------
  *
- * TclTrimRight --
+ * UtfWellFormedEnd --
+ *	Checks the end of utf string is malformed, if yes - wraps bytes
+ *	to the given buffer (as well-formed NTS string).  The buffer
+ *	argument should be initialized by the caller and ready to use.
+ *
+ * Results:
+ *	The bytes with well-formed end of the string.
  *
- *	Takes two counted strings in the Tcl encoding which must both be null
- *	terminated. Conceptually trims from the right side of the first string
- *	all characters found in the second string.
+ * Side effects:
+ *	Buffer (DString) may be allocated, so must be released.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static inline const char*
+UtfWellFormedEnd(
+    Tcl_DString *buffer,	/* Buffer used to hold well-formed string. */
+    const char *bytes,		/* Pointer to the beginning of the string. */
+    int length)			/* Length of the string. */
+{
+    const char *l = bytes + length;
+    const char *p = Tcl_UtfPrev(l, bytes);
+
+    if (Tcl_UtfCharComplete(p, l - p)) {
+	return bytes;
+    }
+    /* 
+     * Malformed utf-8 end, be sure we've NTS to safe compare of end-character,
+     * avoid segfault by access violation out of range.
+     */
+    Tcl_DStringAppend(buffer, bytes, length);
+    return Tcl_DStringValue(buffer);
+}
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclTrimRight --
+ *	Takes two counted strings in the Tcl encoding.  Conceptually
+ *	finds the sub string (offset) to trim from the right side of the
+ *	first string all characters found in the second string.
  *
  * Results:
  *	The number of bytes to be removed from the end of the string.
@@ -1662,8 +1697,8 @@ Tcl_Backslash(
  *----------------------------------------------------------------------
  */
 
-int
-TclTrimRight(
+static inline int
+TrimRight(
     const char *bytes,		/* String to be trimmed... */
     int numBytes,		/* ...and its length in bytes */
     const char *trim,		/* String of trim characters... */
@@ -1673,18 +1708,6 @@ TclTrimRight(
     int pInc;
     Tcl_UniChar ch1 = 0, ch2 = 0;
 
-    if ((bytes[numBytes] != '\0') || (trim[numTrim] != '\0')) {
-	Tcl_Panic("TclTrimRight works only on null-terminated strings");
-    }
-
-    /*
-     * Empty strings -> nothing to do.
-     */
-
-    if ((numBytes == 0) || (numTrim == 0)) {
-	return 0;
-    }
-
     /*
      * Outer loop: iterate over string to be trimmed.
      */
@@ -1723,15 +1746,46 @@ TclTrimRight(
 
     return numBytes - (p - bytes);
 }
+
+int
+TclTrimRight(
+    const char *bytes,	/* String to be trimmed... */
+    int numBytes,	/* ...and its length in bytes */
+    const char *trim,	/* String of trim characters... */
+    int numTrim)	/* ...and its length in bytes */
+{
+    int res;
+    Tcl_DString bytesBuf, trimBuf;
+
+    /* Empty strings -> nothing to do */
+    if ((numBytes == 0) || (numTrim == 0)) {
+	return 0;
+    }
+
+    Tcl_DStringInit(&bytesBuf);
+    Tcl_DStringInit(&trimBuf);
+    bytes = UtfWellFormedEnd(&bytesBuf, bytes, numBytes);
+    trim = UtfWellFormedEnd(&trimBuf, trim, numTrim);
+
+    res = TrimRight(bytes, numBytes, trim, numTrim);
+    if (res > numBytes) {
+	res = numBytes;
+    }
+
+    Tcl_DStringFree(&bytesBuf);
+    Tcl_DStringFree(&trimBuf);
+
+    return res;
+}
 
 /*
  *----------------------------------------------------------------------
  *
  * TclTrimLeft --
  *
- *	Takes two counted strings in the Tcl encoding which must both be null
- *	terminated. Conceptually trims from the left side of the first string
- *	all characters found in the second string.
+ *	Takes two counted strings in the Tcl encoding.  Conceptually
+ *	finds the sub string (offset) to trim from the left side of the
+ *	first string all characters found in the second string.
  *
  * Results:
  *	The number of bytes to be removed from the start of the string.
@@ -1742,8 +1796,8 @@ TclTrimRight(
  *----------------------------------------------------------------------
  */
 
-int
-TclTrimLeft(
+static inline int
+TrimLeft(
     const char *bytes,		/* String to be trimmed... */
     int numBytes,		/* ...and its length in bytes */
     const char *trim,		/* String of trim characters... */
@@ -1752,18 +1806,6 @@ TclTrimLeft(
     const char *p = bytes;
 	Tcl_UniChar ch1 = 0, ch2 = 0;
 
-    if ((bytes[numBytes] != '\0') || (trim[numTrim] != '\0')) {
-	Tcl_Panic("TclTrimLeft works only on null-terminated strings");
-    }
-
-    /*
-     * Empty strings -> nothing to do.
-     */
-
-    if ((numBytes == 0) || (numTrim == 0)) {
-	return 0;
-    }
-
     /*
      * Outer loop: iterate over string to be trimmed.
      */
@@ -1798,10 +1840,99 @@ TclTrimLeft(
 
 	p += pInc;
 	numBytes -= pInc;
-    } while (numBytes);
+    } while (numBytes > 0);
 
     return p - bytes;
 }
+
+int
+TclTrimLeft(
+    const char *bytes,	/* String to be trimmed... */
+    int numBytes,	/* ...and its length in bytes */
+    const char *trim,	/* String of trim characters... */
+    int numTrim)	/* ...and its length in bytes */
+{
+    int res;
+    Tcl_DString bytesBuf, trimBuf;
+
+    /* Empty strings -> nothing to do */
+    if ((numBytes == 0) || (numTrim == 0)) {
+	return 0;
+    }
+
+    Tcl_DStringInit(&bytesBuf);
+    Tcl_DStringInit(&trimBuf);
+    bytes = UtfWellFormedEnd(&bytesBuf, bytes, numBytes);
+    trim = UtfWellFormedEnd(&trimBuf, trim, numTrim);
+
+    res = TrimLeft(bytes, numBytes, trim, numTrim);
+    if (res > numBytes) {
+	res = numBytes;
+    }
+
+    Tcl_DStringFree(&bytesBuf);
+    Tcl_DStringFree(&trimBuf);
+
+    return res;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclTrim --
+ *	Finds the sub string (offset) to trim from both sides of the
+ *	first string all characters found in the second string.
+ *
+ * Results:
+ *	The number of bytes to be removed from the start of the string
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclTrim(
+    const char *bytes,	/* String to be trimmed... */
+    int numBytes,	/* ...and its length in bytes */
+    const char *trim,	/* String of trim characters... */
+    int numTrim,	/* ...and its length in bytes */
+    int *trimRight)		/* Offset from the end of the string. */
+{
+    int trimLeft;
+    Tcl_DString bytesBuf, trimBuf;
+
+    /* Empty strings -> nothing to do */
+    if ((numBytes == 0) || (numTrim == 0)) {
+	*trimRight = 0;
+	return 0;
+    }
+
+    Tcl_DStringInit(&bytesBuf);
+    Tcl_DStringInit(&trimBuf);
+    bytes = UtfWellFormedEnd(&bytesBuf, bytes, numBytes);
+    trim = UtfWellFormedEnd(&trimBuf, trim, numTrim);
+
+    trimLeft = TrimLeft(bytes, numBytes, trim, numTrim);
+    if (trimLeft > numBytes) {
+	trimLeft = numBytes;
+    }
+    numBytes -= trimLeft;
+    *trimRight = 0;
+    if (numBytes) {
+	bytes += trimLeft;
+	*trimRight = TrimRight(bytes, numBytes, trim, numTrim);
+	if (*trimRight > numBytes) {
+	    *trimRight = numBytes;
+	}
+    }
+
+    Tcl_DStringFree(&bytesBuf);
+    Tcl_DStringFree(&trimBuf);
+
+    return trimLeft;
+}
 
 /*
  *----------------------------------------------------------------------
@@ -1869,30 +2000,20 @@ Tcl_Concat(
     result = ckalloc((unsigned) (bytesNeeded + argc));
 
     for (p = result, i = 0;  i < argc;  i++) {
-	int trim, elemLength;
+	int triml, trimr, elemLength;
 	const char *element;
 
 	element = argv[i];
 	elemLength = strlen(argv[i]);
 
-	/*
-	 * Trim away the leading whitespace.
-	 */
-
-	trim = TclTrimLeft(element, elemLength, CONCAT_TRIM_SET,
-		CONCAT_WS_SIZE);
-	element += trim;
-	elemLength -= trim;
-
-	/*
-	 * Trim away the trailing whitespace. Do not permit trimming to expose
-	 * a final backslash character.
-	 */
+	/* Trim away the leading/trailing whitespace. */
+	triml = TclTrim(element, elemLength, CONCAT_TRIM_SET,
+		CONCAT_WS_SIZE, &trimr);
+	element += triml;
+	elemLength -= triml + trimr;
 
-	trim = TclTrimRight(element, elemLength, CONCAT_TRIM_SET,
-		CONCAT_WS_SIZE);
-	trim -= trim && (element[elemLength - trim - 1] == '\\');
-	elemLength -= trim;
+	/* Do not permit trimming to expose a final backslash character. */
+	elemLength += trimr && (element[elemLength - 1] == '\\');
 
 	/*
 	 * If we're left with empty element after trimming, do nothing.
@@ -2012,28 +2133,18 @@ Tcl_ConcatObj(
     Tcl_SetObjLength(resPtr, 0);
 
     for (i = 0;  i < objc;  i++) {
-	int trim;
+	int triml, trimr;
 
 	element = TclGetStringFromObj(objv[i], &elemLength);
 
-	/*
-	 * Trim away the leading whitespace.
-	 */
-
-	trim = TclTrimLeft(element, elemLength, CONCAT_TRIM_SET,
-		CONCAT_WS_SIZE);
-	element += trim;
-	elemLength -= trim;
-
-	/*
-	 * Trim away the trailing whitespace. Do not permit trimming to expose
-	 * a final backslash character.
-	 */
+	/* Trim away the leading/trailing whitespace. */
+	triml = TclTrim(element, elemLength, CONCAT_TRIM_SET,
+		CONCAT_WS_SIZE, &trimr);
+	element += triml;
+	elemLength -= triml + trimr;
 
-	trim = TclTrimRight(element, elemLength, CONCAT_TRIM_SET,
-		CONCAT_WS_SIZE);
-	trim -= trim && (element[elemLength - trim - 1] == '\\');
-	elemLength -= trim;
+	/* Do not permit trimming to expose a final backslash character. */
+	elemLength += trimr && (element[elemLength - 1] == '\\');
 
 	/*
 	 * If we're left with empty element after trimming, do nothing.