git_cache.py: Clobber git repos if the config is corrupt

git_cache.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 """A git command for managing a local cache of git repositories."""
 
 from __future__ import print_function
 import errno
 import logging
@@ skipping 20 matching lines @@
 try:
   # pylint: disable=E0602
   WinErr = WindowsError
 except NameError:
   class WinErr(Exception):
     pass
 
 class LockError(Exception):
   pass
 
-class RefsHeadsFailedToFetch(Exception):
+class ClobberNeeded(Exception):
   pass
 
 class Lockfile(object):
   """Class to represent a cross-platform process-specific lockfile."""
 
   def __init__(self, path, timeout=0):
     self.path = os.path.abspath(path)
     self.timeout = timeout
     self.lockfile = self.path + ".lock"
     self.pid = os.getpid()
@@ skipping 187 matching lines @@
     env.setdefault('GIT_ASKPASS', 'true')
     env.setdefault('SSH_ASKPASS', 'true')
     self.print('running "git %s" in "%s"' % (' '.join(cmd), cwd))
     gclient_utils.CheckCallAndFilter([self.git_exe] + cmd, **kwargs)
 
   def config(self, cwd=None):
     if cwd is None:
       cwd = self.mirror_path
 
     # Don't run git-gc in a daemon.  Bad things can happen if it gets killed.
-    self.RunGit(['config', 'gc.autodetach', '0'], cwd=cwd)
+    try:
+      self.RunGit(['config', 'gc.autodetach', '0'], cwd=cwd)
+    except subprocess.CalledProcessError:
+      # Hard error, need to clobber.
+      raise ClobberNeeded()
 
     # Don't combine pack files into one big pack file.  It's really slow for
     # repositories, and there's no way to track progress and make sure it's
     # not stuck.
     self.RunGit(['config', 'gc.autopacklimit', '0'], cwd=cwd)
 
     # Allocate more RAM for cache-ing delta chains, for better performance
     # of "Resolving deltas".
     self.RunGit(['config', 'core.deltaBaseCacheLimit',
                  gclient_utils.DefaultDeltaBaseCacheLimit()], cwd=cwd)
@@ skipping 140 matching lines @@
     fetch_cmd = ['fetch'] + v + d + ['origin']
     fetch_specs = subprocess.check_output(
         [self.git_exe, 'config', '--get-all', 'remote.origin.fetch'],
         cwd=rundir).strip().splitlines()
     for spec in fetch_specs:
       try:
         self.print('Fetching %s' % spec)
         self.RunGit(fetch_cmd + [spec], cwd=rundir, retry=True)
       except subprocess.CalledProcessError:
         if spec == '+refs/heads/*:refs/heads/*':
-          raise RefsHeadsFailedToFetch
+          raise ClobberNeeded()  # Corrupted cache.
         logging.warn('Fetch of %s failed' % spec)
 
   def populate(self, depth=None, shallow=False, bootstrap=False,
                verbose=False, ignore_lock=False, lock_timeout=0):
     assert self.GetCachePath()
     if shallow and not depth:
       depth = 10000
     gclient_utils.safe_makedirs(self.GetCachePath())
 
     lockfile = Lockfile(self.mirror_path, lock_timeout)
     if not ignore_lock:
       lockfile.lock()
 
     tempdir = None
     try:
       tempdir = self._ensure_bootstrapped(depth, bootstrap)
       rundir = tempdir or self.mirror_path
       self._fetch(rundir, verbose, depth)
-    except RefsHeadsFailedToFetch:
+    except ClobberNeeded:
       # This is a major failure, we need to clean and force a bootstrap.
       gclient_utils.rmtree(rundir)
       self.print(GIT_CACHE_CORRUPT_MESSAGE)
       tempdir = self._ensure_bootstrapped(depth, bootstrap, force=True)
       assert tempdir
       self._fetch(tempdir or self.mirror_path, verbose, depth)
     finally:
       if tempdir:
         try:
           if os.path.exists(self.mirror_path):
@@ skipping 285 matching lines @@
   dispatcher = subcommand.CommandDispatcher(__name__)
   return dispatcher.execute(OptionParser(), argv)
 
 
 if __name__ == '__main__':
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)