Test runner: fix empty patches; better error message for missing test files; correct .gitignore ent…

tools/testrunner/server/work_handler.py

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 110 matching lines @@
     if code != 0:
       self._SendResponse("Error trying to check out base revision.")
       return False
     code = self._Call("git clean -f -d")
     if code != 0:
       self._SendResponse("Failed to reset checkout")
       return False
     return True
 
   def _ApplyPatch(self, patch):
+    if not patch: return True  # Just skip if the patch is empty.
     patchfilename = "_dtest_incoming_patch.patch"
     with open(patchfilename, "w") as f:
       f.write(patch)
     code = self._Call("git apply %s" % patchfilename)
     if code != 0:
       self._SendResponse("Error applying patch.")
       return False
     return True
 
   def _Call(self, cmd):
     return subprocess.call(cmd, shell=True)
 
 
 class WorkSocketServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer):
   def __init__(self, daemon):
     address = (daemon.ip, constants.PEER_PORT)
     SocketServer.TCPServer.__init__(self, address, WorkHandler)
     self.job_lock = threading.Lock()
     self.daemon = daemon