Index: generic/nsfStack.c
===================================================================
diff -u -N -ref01bf0b1fa63c266b7276dae6c1f376587221fa -r1f532a9dd165fbbf7f3a3f470f7661acf4c35fad
--- generic/nsfStack.c	(.../nsfStack.c)	(revision ef01bf0b1fa63c266b7276dae6c1f376587221fa)
+++ generic/nsfStack.c	(.../nsfStack.c)	(revision 1f532a9dd165fbbf7f3a3f470f7661acf4c35fad)
@@ -637,11 +637,14 @@
                                int offset,
                                Tcl_CallFrame **callingProcFramePtrPtr,
                                Tcl_CallFrame **callingFramePtrPtr) {
-  register Tcl_CallFrame *varFramePtr = (Tcl_CallFrame *)Tcl_Interp_varFramePtr(interp);
-  int lvl = Tcl_CallFrame_level(varFramePtr);
+  register Tcl_CallFrame *varFramePtr;
+  int                     lvl;
 
   nonnull_assert(interp != NULL);
 
+  varFramePtr = (Tcl_CallFrame *)Tcl_Interp_varFramePtr(interp);
+  lvl = Tcl_CallFrame_level(varFramePtr);
+
   for (; likely(varFramePtr != NULL); varFramePtr = Tcl_CallFrame_callerVarPtr(varFramePtr)) {
     register unsigned int flags = (unsigned int)Tcl_CallFrame_isProcCallFrame(varFramePtr);
 
@@ -865,7 +868,7 @@
     cscPtr = (NsfCallStackContent *)Tcl_CallFrame_clientData(varFramePtr);
     assert(cscPtr != NULL);
 
-    /*fprintf(stderr,"	--- frame %p cmdPtr %p NSF_CSC_TYPE_ENSEMBLE %d NSF_CSC_CALL_IS_ENSEMBLE %d \
+    /*fprintf(stderr,"--- frame %p cmdPtr %p NSF_CSC_TYPE_ENSEMBLE %d NSF_CSC_CALL_IS_ENSEMBLE %d \
                          NSF_CSC_TYPE_INACTIVE %d\n",
             varFramePtr,
             cscPtr->cmdPtr,
@@ -963,7 +966,7 @@
 
     assert(cscPtr != NULL);
 
-    /*fprintf(stderr,	"--- frame %p cmdPtr %p cmd %s NSF_CSC_TYPE_ENSEMBLE %d \
+    /*fprintf(stderr, "--- frame %p cmdPtr %p cmd %s NSF_CSC_TYPE_ENSEMBLE %d \
                         NSF_CSC_CALL_IS_ENSEMBLE %d NSF_CSC_TYPE_INACTIVE %d\n",
             framePtr,
             cscPtr->cmdPtr,