Index: generic/tclCkalloc.c
===================================================================
RCS file: /cvsroot/tcl/tcl/generic/tclCkalloc.c,v
retrieving revision 1.19
diff -u -r1.19 tclCkalloc.c
--- generic/tclCkalloc.c	19 Jan 2003 07:21:18 -0000	1.19
+++ generic/tclCkalloc.c	15 Aug 2005 00:59:24 -0000
@@ -373,6 +373,10 @@
     if (validate_memory)
         Tcl_ValidateAllMemory (file, line);
 
+    if (size == 0) {
+        panic("attempt to ckalloc 0 bytes, %s line %d", size, file, line);
+    }
+
     result = (struct mem_header *) TclpAlloc((unsigned)size + 
                               sizeof(struct mem_header) + HIGH_GUARD_SIZE);
     if (result == NULL) {
