Index: generic/tclCompile.c
===================================================================
RCS file: /cvsroot/tcl/tcl/generic/tclCompile.c,v
retrieving revision 1.28
diff -u -r1.28 tclCompile.c
--- generic/tclCompile.c	2001/11/21 02:36:20	1.28
+++ generic/tclCompile.c	2001/11/22 00:15:05
@@ -1584,8 +1584,23 @@
     codePtr->numAuxDataItems = envPtr->auxDataArrayNext;
     codePtr->numCmdLocBytes = cmdLocBytes;
     codePtr->maxExceptDepth = envPtr->maxExceptDepth;
-    codePtr->maxStackDepth = envPtr->maxStackDepth;
     
+    /* Temporary bug fix, quick and dirty. As the maxStackDepth is 
+     * sometimes underestimated by the compiler, we replace by a
+     * safe overestimate which relies on the following facts:
+     *   1 - no instruction has a stack balance > 1
+     *   2 - there are always more bytes than instructions
+     *
+     * Less crude upper bounds will take this place in the future.
+     * Remark that the cost of overestimating is a possible increase 
+     * in memory consumption; the cost of underestimating is a
+     * possible SEGFAULT.
+     *
+     *   codePtr->maxStackDepth = envPtr->maxStackDepth;
+     */
+
+    codePtr->maxStackDepth = codePtr->numCodeBytes;
+
     p += sizeof(ByteCode);
     codePtr->codeStart = p;
     memcpy((VOID *) p, (VOID *) envPtr->codeStart, (size_t) codeBytes);
Index: generic/tclExecute.c
===================================================================
RCS file: /cvsroot/tcl/tcl/generic/tclExecute.c,v
retrieving revision 1.42
diff -u -r1.42 tclExecute.c
--- generic/tclExecute.c	2001/11/20 22:47:58	1.42
+++ generic/tclExecute.c	2001/11/22 00:15:08
@@ -268,8 +268,7 @@
 static char *		StringForResultCode _ANSI_ARGS_((int result));
 static void		ValidatePcAndStackTop _ANSI_ARGS_((
 			    ByteCode *codePtr, unsigned char *pc,
-			    int stackTop, int stackLowerBound,
-			    int stackUpperBound));
+			    int stackTop, int stackLowerBound));
 #endif
 static int		VerifyExprObjType _ANSI_ARGS_((Tcl_Interp *interp,
 			    Tcl_Obj *objPtr));
@@ -1049,8 +1048,7 @@
 
     for (;;) {
 #ifdef TCL_COMPILE_DEBUG
-	ValidatePcAndStackTop(codePtr, pc, stackTop, initStackTop,
-		eePtr->stackEnd);
+	ValidatePcAndStackTop(codePtr, pc, stackTop, initStackTop);
         if (traceInstructions) {
             fprintf(stdout, "%2d: %2d ", iPtr->numLevels, stackTop);
             TclPrintInstruction(codePtr, pc);
@@ -4090,8 +4088,7 @@
 
 #ifdef TCL_COMPILE_DEBUG
 static void
-ValidatePcAndStackTop(codePtr, pc, stackTop, stackLowerBound,
-        stackUpperBound)
+ValidatePcAndStackTop(codePtr, pc, stackTop, stackLowerBound)
     register ByteCode *codePtr; /* The bytecode whose summary is printed
 				 * to stdout. */
     unsigned char *pc;		/* Points to first byte of a bytecode
@@ -4100,8 +4097,9 @@
 				 * stackLowerBound and stackUpperBound
 				 * (inclusive). */
     int stackLowerBound;	/* Smallest legal value for stackTop. */
-    int stackUpperBound;	/* Greatest legal value for stackTop. */
 {
+int stackUpperBound = stackLowerBound +  codePtr->maxStackDepth;	
+                                /* Greatest legal value for stackTop. */
     unsigned int relativePc = (unsigned int) (pc - codePtr->codeStart);
     unsigned int codeStart = (unsigned int) codePtr->codeStart;
     unsigned int codeEnd = (unsigned int)
