cpplib.c (do_define): Only free the old definition if it actually had one.

	* cpplib.c (do_define): Only free the old definition if it
	actually had one.

From-SVN: r31964

gcc/ChangeLog

+2000-02-13  Zack Weinberg  <zack@wolery.cumb.org>
+
+	* cpplib.c (do_define): Only free the old definition if it
+	actually had one.
+
 2000-02-13   Neil Booth  <NeilB@earthling.net>
 
 	* cppfiles.c (read_and_prescan): When emitting deferred

gcc/cpplib.c

@@ -715,8 +715,9 @@ do_define (pfile, keyword)
       if (hp->type != T_POISON)
 	{
 	  /* Replace the old definition.  */
+	  if (hp->type == T_MACRO)
+	    free_definition (hp->value.defn);
 	  hp->type = T_MACRO;
-	  free_definition (hp->value.defn);
 	  hp->value.defn = mdef.defn;
 	}
     }