Index: TODO
===================================================================
diff -u -r1398015d9294ce3adec8b1d5dc6e98f7c717b243 -r63a1262db92115ac1026267b308ca14a190576ce
--- TODO	(.../TODO)	(revision 1398015d9294ce3adec8b1d5dc6e98f7c717b243)
+++ TODO	(.../TODO)	(revision 63a1262db92115ac1026267b308ca14a190576ce)
@@ -3792,9 +3792,10 @@
 nsf.c, nsf.h, nsfStack.c, nx.tcl, tcl-cool.tcl, xotcl2.tcl
 - fix spelling in comments
 - strip unneeded space
+- fixed potential crash when generating error message about argument usage 
+  when called without a callstack
 
 
-
 ========================================================================
 TODO:
 
Index: generic/nsf.c
===================================================================
diff -u -r1398015d9294ce3adec8b1d5dc6e98f7c717b243 -r63a1262db92115ac1026267b308ca14a190576ce
--- generic/nsf.c	(.../nsf.c)	(revision 1398015d9294ce3adec8b1d5dc6e98f7c717b243)
+++ generic/nsf.c	(.../nsf.c)	(revision 63a1262db92115ac1026267b308ca14a190576ce)
@@ -1,4 +1,4 @@
-/* [a-z]  
+/* 
  *  nsf.c --
  *
  *      Basic Machinery of the Next Scripting Framework, a Tcl based framework
@@ -3202,7 +3202,7 @@
   Tcl_Obj *resultObj;
 
   /* NsfShowStack(interp);*/
-  if ((cscPtr->flags & NSF_CSC_CALL_IS_ENSEMBLE)) {
+  if (cscPtr && (cscPtr->flags & NSF_CSC_CALL_IS_ENSEMBLE)) {
     resultObj = Tcl_NewListObj(0, NULL);
     Tcl_ListObjAppendElement(interp, resultObj,
 			     Tcl_NewStringObj(Tcl_GetCommandName(interp, cscPtr->cmdPtr), -1));