[ns] otcl instvar in global :: scope

[Orion Hodson <O.Hodson@cs.ucl.ac.uk>]

Invoking instvar in global scope causes both ns and otclsh to
segfault.  There's small patch below that detects the problem and
reports an error; seemed easier than adding support for an undesirable
feature.

% Class Bagel
%
% Bagel instproc init {} {
%        $self set diameter 5cm
% }
%
% Bagel motherOfAllBagels 
% motherOfAllBagels instvar diameter
Segmentation fault (core dumped)

--- otcl.c.orig Sun Jun 18 22:22:18 2000 +++ otcl.c Sun Jun 18
22:31:26 2000 @@ -1426,10 +1426,11 @@
 OTclOInstVarOne(OTclObject* obj, Tcl_Interp *in, char *frameName, char *varName
, char *localName, int flags)
 {
   Interp* iPtr = (Interp*)in;
-  CallFrame* saved = iPtr->varFramePtr->callerVarPtr;
-  int level = iPtr->varFramePtr->level;
   int result = TCL_ERROR;
 
+  if (iPtr->varFramePtr) {
+    CallFrame* saved = iPtr->varFramePtr->callerVarPtr;
+    int level = iPtr->varFramePtr->level;
   /*
    * Fake things as if the caller's stack frame is just over
    * the object, then use UpVar to suck the object's variable
@@ -1440,6 +1441,9 @@
   result = Tcl_UpVar(in, frameName, varName, localName, flags);
   iPtr->varFramePtr->callerVarPtr = saved;
   iPtr->varFramePtr->level = level;
+  } else {
+    Tcl_SetResult(in, "no instvar in global :: scope", TCL_STATIC);    
+  }
   return result;
 }

cheers
- Orion.

PS, pointer on http://www.isi.edu/nsnam/ns/ns-lists.html to list
archives wants redirecting to isi.