Index: smalltalk-3.0/libgst/prims.def
===================================================================
--- smalltalk-3.0.orig/libgst/prims.def	2008-01-08 17:30:06.000000000 +0000
+++ smalltalk-3.0/libgst/prims.def	2008-01-08 17:47:21.000000000 +0000
@@ -5071,13 +5071,21 @@
       fileName = _gst_to_cstring (oop2);
       errno = 0;
 
+      /* first overwrite the stack top with true. When we resume from
+	 the save, the stack will be in this state. See below. */
+      SET_STACKTOP_BOOLEAN(1);
+
       PROTECT_CURRENT_PROCESS_WITH (&localJmpBuf)
 	success = _gst_save_to_file (fileName);
       
       xfree (fileName);
-      if (success)
+      if (success) {
+	/* We're returning in the parent, not resuming from
+	   save. Overwite the stack top again, with false this time,
+	   to let the caller know which side of the fork we're on. */
+	SET_STACKTOP_BOOLEAN(0);
 	PRIM_SUCCEEDED;
-      else
+      } else
         _gst_set_errno (errno);
     }
   UNPOP (1);