Make sure branch-heads is configured whenever requested.

gclient_scm.py

Index: gclient_scm.py
===================================================================
--- gclient_scm.py	(revision 193951)
+++ gclient_scm.py	(working copy)
@@ -316,6 +316,7 @@
       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()
@@ -384,6 +385,8 @@
       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)
@@ -692,32 +695,10 @@
           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.
+    self._UpdateBranchHeads(options, fetch=True)
 
-          # 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
-
     if detach_head:
       # Squelch git's very verbose detached HEAD warning and use our own
       self._Capture(['checkout', '--quiet', '%s' % revision])
@@ -870,6 +851,25 @@
         stderr=subprocess2.PIPE,
         cwd=self.checkout_path).strip()
 
+  def _UpdateBranchHeads(self, options, fetch=False):
+    """Add, and optionally fetch, the "branch-heads" refspecs if requested."""

[M-A Ruel, 2013/04/12 20:28:12]

Adds

[Michael Moss, 2013/04/12 20:58:36]

Done.

+    if hasattr(options, 'with_branch_heads') and options.with_branch_heads:
+      for _ in range(3):
+        try:
+          config_cmd = ['config', 'remote.origin.fetch',
+                        '+refs/branch-heads/*:refs/remotes/branch-heads/*',

[M-A Ruel, 2013/04/12 20:28:12]

I still don't know what branch-heads is supposed to mean. It's a meta-way of
keeping multiple branches? Why not tags?

[Michael Moss, 2013/04/12 20:58:36]

branch-heads is specifically the heads of branches that are mirrored from svn
repositories. It's named that way to help distinguish them from "native" git
branches, and to help isolate them for people who don't ever need them, and thus
don't want to sync that extra data (i.e. only 'refs/heads/*' is fetched by
default).

[M-A Ruel, 2013/04/16 14:44:09]

What you are describing is kinda what lightweight tags are for. So I just want
to know what advantages the custom branch-heads has over using git native
lightweight tags and using "git fetch --tags".

+                        '^\\+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...')
+
   def _Run(self, args, options, **kwargs):
     kwargs.setdefault('cwd', self.checkout_path)
     kwargs.setdefault('print_stdout', True)