Rename log in case of exected failure

test/test.py

@@ -49,7 +49,7 @@ def main():
             sys.stdout.flush()
             if errcode != 0:
                 # Failure: save the log immediately
-                with openLog(name) as f:
+                with openLog(name if not name in xfails else name + "_EXPECTED_FAILURE") as f:
                     f.write("=" * 80)
                     f.write("ERROR: %s %s" % (name, rule))
                     try: