Fix GitBackend.checkout

recipe_engine/package.py

 # Copyright 2015 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 import copy
 import difflib
 import logging
 import operator
 import os
 import subprocess
@@ skipping 202 matching lines @@
     if self.backend.repo_type != package_pb2.DepSpec.GIT:
       buf.repo_type = self.backend.repo_type
 
     return buf
 
   def updates(self, context, other_revision=None):
     """Returns a list of all updates to the branch since the revision this
     repo spec refers to.
     """
     raw_updates = self.raw_updates(
-        context, (other_revision or self.backend.branch_spec(self.branch)))
+        context, (other_revision or 'refs/heads/' + self.branch))
     updates = []
     for rev in raw_updates:
       # TODO(somebody): 'info' is not used.
       info = self._get_commit_info(rev, context)
       updates.append(GitRepoSpec(
           self.project_id,
           self.repo,
           self.branch,
           rev,
           self.path,
@@ skipping 21 matching lines @@
       paths.extend([subdir + os.path.sep, self.proto_file(context).path])
 
     return self.backend.updates(
         self.repo, self.revision, checkout_dir, context.allow_fetch,
         other_revision, paths)
 
   def get_more_recent_revision(self, context, r1, r2):
     """Returns the more recent revision."""
     self.checkout(context)
     if context.allow_fetch:
-      self.run_git(context, 'fetch')
+      self.run_git(context, 'fetch', self.repo, 'refs/heads/master')

[Paweł Hajdan Jr., 2017/02/28 08:44:33]

Similarly I'm worried about assumptions r1 and r2 are on the master branch.

Should there be at least a TODO to remove that assumption?

     args = [
         'rev-list',
         '%s...%s' % (r1, r2),  # Note three dots (...) here.
     ]
     return self.run_git(context, *args).strip().split('\n')[0]
 
   def _get_commit_info(self, rev, context):
     checkout_dir = self._dep_dir(context)
     metadata = self.backend.commit_metadata(
         self.repo, rev, checkout_dir, context.allow_fetch)
@@ skipping 407 matching lines @@
   >>> d = { 'x': 1, 'y': 2 }
   >>> sorted(_updated(d, { 'y': 3, 'z': 4 }).items())
   [('x', 1), ('y', 3), ('z', 4)]
   >>> sorted(d.items())
   [('x', 1), ('y', 2)]
   """
 
   d = copy.copy(d)
   d.update(updates)
   return d