Index: generic/nsfStack.c
===================================================================
diff -u -N -radedd712d56344175e1036b7b908e62054cb8c76 -rb64700f0ea90a2037016ee0bac630a2c88d61a8a
--- generic/nsfStack.c	(.../nsfStack.c)	(revision adedd712d56344175e1036b7b908e62054cb8c76)
+++ generic/nsfStack.c	(.../nsfStack.c)	(revision b64700f0ea90a2037016ee0bac630a2c88d61a8a)
@@ -796,6 +796,7 @@
 static Tcl_CallFrame *
 CallStackNextFrameOfType(Tcl_CallFrame *framePtr, unsigned int flags) {
   NsfCallStackContent *cscPtr;
+
   nonnull_assert(framePtr != NULL);
 
   do {
@@ -807,7 +808,10 @@
     }
     
     if (((unsigned int)Tcl_CallFrame_isProcCallFrame(framePtr) & flags) != 0u) {
-      return framePtr;
+      /*
+       * framePtr has already the return value.
+       */
+      break;
     }
 
     framePtr = Tcl_CallFrame_callerPtr(framePtr);