Index: generic/nsf.c
===================================================================
diff -u -r55715c476a861bb380e2cf5e7e31c056311d157a -rced9ad76621829c8f4e8a232335d494ab462252e
--- generic/nsf.c	(.../nsf.c)	(revision 55715c476a861bb380e2cf5e7e31c056311d157a)
+++ generic/nsf.c	(.../nsf.c)	(revision ced9ad76621829c8f4e8a232335d494ab462252e)
@@ -8823,7 +8823,9 @@
 NsfProcDeleteProc(ClientData clientData) {
   NsfProcContext *ctxPtr = (NsfProcContext *)clientData;
 
-  (*ctxPtr->oldDeleteProc)(ctxPtr->oldDeleteData);
+  if (ctxPtr->oldDeleteProc) {
+    (*ctxPtr->oldDeleteProc)(ctxPtr->oldDeleteData);
+  }
   if (ctxPtr->paramDefs) {
     /*fprintf(stderr, "free ParamDefs %p\n", ctxPtr->paramDefs);*/
     ParamDefsRefCountDecr(ctxPtr->paramDefs);
@@ -19880,7 +19882,7 @@
 
   if (newObjProc) {
     /* add a wrapper */
-    /*fprintf(stderr, "NsfMethodAliasCmd cmd %p\n", cmd);*/
+    /*fprintf(stderr, "NsfMethodAliasCmd add wrapper cmd %p\n", cmd);*/
     NsfCommandPreserve(cmd);
     tcd = NEW(AliasCmdClientData);
     tcd->cmdName    = object->cmdName;
@@ -19900,6 +19902,7 @@
      * depending on a volatile client data)
      */
     tcd = Tcl_Command_objClientData(cmd);
+    /*fprintf(stderr, "NsfMethodAliasCmd no wrapper cmd %p\n", cmd);*/
   }
 
   flags = 0;