Index: unix/tclUnixInit.c
==================================================================
--- unix/tclUnixInit.c
+++ unix/tclUnixInit.c
@@ -1109,11 +1109,11 @@
     if (stackGrowsDown == -1) {
 	/*
 	 * Not initialised!
 	 */
 
-	stackGrowsDown = StackGrowsDown(&result);
+	stackGrowsDown = StackGrowsDown(NULL);
     }
 #endif
     
     /*
      * The first time through in a thread: record the "outermost" stack
@@ -1184,10 +1184,13 @@
 int
 StackGrowsDown(
     int *parent)
 {
     int here;
+    if (!parent) {
+	return StackGrowsDown(&here);
+    }
     return (&here < parent);
 }
 #endif
 
 /*