Don't cache the fact that codereview.settings wasn't found.

gcl.py

 #!/usr/bin/python
 # Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """\
 Wrapper script around Rietveld's upload.py that simplifies working with groups
 of files.
 """
 
@@ skipping 109 matching lines @@
   if filename not in FILES_CACHE:
     # Don't try to look up twice.
     FILES_CACHE[filename] = None
     # First we check if we have a cached version.
     try:
       cached_file = os.path.join(GetCacheDir(), filename)
     except gclient_utils.Error:
       return None
     if (not os.path.exists(cached_file) or
         (time.time() - os.stat(cached_file).st_mtime) > max_age):
-      dir_info = SVN.CaptureInfo(".")
-      repo_root = dir_info["Repository Root"]
+      dir_info = SVN.CaptureInfo('.')
+      repo_root = dir_info['Repository Root']
       if use_root:
         url_path = repo_root
       else:
-        url_path = dir_info["URL"]
+        url_path = dir_info['URL']
       while True:
         # Look in the repository at the current level for the file.
         for _ in range(5):
-          content = ""
+          content = None
           try:
             # Take advantage of the fact that svn won't output to stderr in case
             # of success but will do in case of failure so don't mind putting
             # stderr into content_array.
             content_array = []
-            svn_path = url_path + "/" + filename
+            svn_path = url_path + '/' + filename
             args = ['cat', svn_path]
             if sys.platform != 'darwin':
               # MacOSX 10.5.2 has a bug with svn 1.4.4 that will trigger the
               # 'Can\'t get username or password' and can be fixed easily.
               # The fix doesn't work if the user upgraded to svn 1.6.x. Bleh.
               # I don't have time to fix their broken stuff.
               args.append('--non-interactive')
             SVN.RunAndFilterOutput(args, cwd='.',
                                    filter_fn=content_array.append)
             # Exit the loop if the file was found. Override content.
@@ skipping 11 matching lines @@
             if not content_array[0].startswith('svn: File not found:'):
               # Try again.
               continue
         if content:
           break
         if url_path == repo_root:
           # Reached the root. Abandoning search.
           break
         # Go up one level to try again.
         url_path = os.path.dirname(url_path)
-      # Write a cached version even if there isn't a file, so we don't try to
-      # fetch it each time.
-      gclient_utils.FileWrite(cached_file, content)
+      if content is not None or filename != CODEREVIEW_SETTINGS_FILE:
+        # Write a cached version even if there isn't a file, so we don't try to
+        # fetch it each time. codereview.settings must always be present so do
+        # not cache negative.
+        gclient_utils.FileWrite(cached_file, content or '')
     else:
       content = gclient_utils.FileRead(cached_file, 'r')
     # Keep the content cached in memory.
     FILES_CACHE[filename] = content
   return FILES_CACHE[filename]
 
 
 def GetCodeReviewSetting(key):
   """Returns a value for the given key for this repository."""
   # Use '__just_initialized' as a flag to determine if the settings were
@@ skipping 1130 matching lines @@
     if command:
       return command(argv[1:])
     # Unknown command, try to pass that to svn
     return CMDpassthru(argv)
   except gclient_utils.Error, e:
     print('Got an exception')
     print(str(e))
 
 if __name__ == "__main__":
   sys.exit(main(sys.argv[1:]))