Make sure branch-heads is configured whenever requested.

gclient_scm.py

 # Copyright (c) 2012 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.
 
 """Gclient-specific SCM-specific operations."""
 
 import logging
 import os
 import posixpath
 import re
@@ skipping 298 matching lines @@
     # unit test pass. (and update the comment above)
     if current_url != url and url != 'git://foo':
       print('_____ switching %s to a new upstream' % self.relpath)
       # Make sure it's clean
       self._CheckClean(rev_str)
       # Switch over to the new upstream
       self._Run(['remote', 'set-url', 'origin', url], options)
       quiet = []
       if not options.verbose:
         quiet = ['--quiet']
+      self._UpdateBranchHeads(options, fetch=False)
       self._Run(['fetch', 'origin', '--prune'] + quiet, options)
       self._Run(['reset', '--hard', revision] + quiet, options)
       self.UpdateSubmoduleConfig()
       files = self._Capture(['ls-files']).splitlines()
       file_list.extend([os.path.join(self.checkout_path, f) for f in files])
       return
 
     cur_branch = self._GetCurrentBranch()
 
     # Cases:
@@ skipping 48 matching lines @@
             print(str(e))
             print('Sleeping %.1f seconds and retrying...' % backoff_time)
             time.sleep(backoff_time)
             backoff_time *= 1.3
             continue
           raise
 
       if verbose:
         print(remote_output.strip())
 
+      self._UpdateBranchHeads(options, fetch=True)
+
     # This is a big hammer, debatable if it should even be here...
     if options.force or options.reset:
       self._Run(['reset', '--hard', 'HEAD'], options)
 
     if current_type == 'detached':
       # case 0
       self._CheckClean(rev_str)
       self._CheckDetachedHead(rev_str, options)
       self._Capture(['checkout', '--quiet', '%s' % revision])
       if not printed_path:
@@ skipping 288 matching lines @@
         # Too bad we don't have access to the actual output yet.
         # We should check for "transfer closed with NNN bytes remaining to
         # read". In the meantime, just make sure .git exists.
         if (e.returncode == 128 and
             os.path.exists(os.path.join(self.checkout_path, '.git'))):
           print(str(e))
           print('Retrying...')
           continue
         raise e
 
-    for _ in range(3):
-      try:
-        # Add the "branch-heads" refspecs. Do this separately from the clone
-        # command since apparently some versions of git don't support 'clone
-        # --config'.
-        # Don't assume 'with_branch_heads' is added by 'gclient sync' setup,
-        # since _Clone() can by reached in roundabout ways (e.g. 'gclient
-        # revert').
-        if hasattr(options, 'with_branch_heads') and options.with_branch_heads:
-          config_cmd = ['config', 'remote.origin.fetch',
-                        '+refs/branch-heads/*:refs/remotes/branch-heads/*',
-                        '^\\+refs/branch-heads/\\*:.*$']
-          self._Run(config_cmd, options)
-
-          # Update the "branch-heads" remote-tracking branches, since we might
-          # need it to checkout a specific revision below.
-          fetch_cmd = ['fetch', 'origin']
-          if options.verbose:
-            fetch_cmd.append('--verbose')
-          self._Run(fetch_cmd, options)
-        break
-      except subprocess2.CalledProcessError, e:
-        print(str(e))
-        print('Retrying...')
-        continue
+    # Update the "branch-heads" remote-tracking branches, since we might need it
+    # to checkout a specific revision below.
+    self._UpdateBranchHeads(options, fetch=True)
 
     if detach_head:
       # Squelch git's very verbose detached HEAD warning and use our own
       self._Capture(['checkout', '--quiet', '%s' % revision])
       print(
         ('Checked out %s to a detached HEAD. Before making any commits\n'
          'in this repo, you should use \'git checkout <branch>\' to switch to\n'
          'an existing branch or use \'git checkout origin -b <branch>\' to\n'
          'create a new branch for your work.') % revision)
 
@@ skipping 133 matching lines @@
     if branch == 'HEAD':
       return None
     return branch
 
   def _Capture(self, args):
     return subprocess2.check_output(
         ['git'] + args,
         stderr=subprocess2.PIPE,
         cwd=self.checkout_path).strip()
 
+  def _UpdateBranchHeads(self, options, fetch=False):
+    """Adds, and optionally fetches, "branch-heads" refspecs if requested."""
+    if hasattr(options, 'with_branch_heads') and options.with_branch_heads:
+      backoff_time = 5
+      for _ in range(3):
+        try:
+          config_cmd = ['config', 'remote.origin.fetch',
+                        '+refs/branch-heads/*:refs/remotes/branch-heads/*',
+                        '^\\+refs/branch-heads/\\*:.*$']
+          self._Run(config_cmd, options)
+          if fetch:
+            fetch_cmd = ['fetch', 'origin']
+            if options.verbose:
+              fetch_cmd.append('--verbose')
+            self._Run(fetch_cmd, options)
+          break
+        except subprocess2.CalledProcessError, e:
+          print(str(e))
+          print('Retrying in %.1f seconds...' % backoff_time)
+          time.sleep(backoff_time)
+          backoff_time *= 1.3
+
   def _Run(self, args, options, **kwargs):
     kwargs.setdefault('cwd', self.checkout_path)
     kwargs.setdefault('print_stdout', True)
     stdout = kwargs.get('stdout', sys.stdout)
     stdout.write('\n________ running \'git %s\' in \'%s\'\n' % (
                  ' '.join(args), kwargs['cwd']))
     gclient_utils.CheckCallAndFilter(['git'] + args, **kwargs)
 
 
 class SVNWrapper(SCMWrapper):
@@ skipping 371 matching lines @@
       new_command.append('--force')
       if command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
         new_command.extend(('--accept', 'theirs-conflict'))
     elif options.manually_grab_svn_rev:
       new_command.append('--force')
       if command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
         new_command.extend(('--accept', 'postpone'))
     elif command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
       new_command.extend(('--accept', 'postpone'))
     return new_command