Add git-map and git-short-map to depot_tools.

git_common.py

Index: git_common.py
diff --git a/git_common.py b/git_common.py
index 1215d9cd41d44385f98583c884188b006b8561f1..b5338252c5d24036e8d27e19cce6e393ee334ade 100644
--- a/git_common.py
+++ b/git_common.py
@@ -29,6 +29,8 @@ import subprocess2
 
 GIT_EXE = 'git.bat' if sys.platform.startswith('win') else 'git'
 
+NO_BRANCH = ('* (no branch)', '* (detached from ')
+
 
 class BadCommitRefException(Exception):
   def __init__(self, refs):
@@ -199,6 +201,28 @@ class ProgressPrinter(object):
     del self._thread
 
 
+def abbrev(ref):
+  return run('rev-parse', '--abbrev-ref', ref)
+
+
+def branches(*args):
+  for line in run('branch', *args).splitlines():
+    if line.startswith(NO_BRANCH):
+      continue
+    yield line.split()[-1]
+
+
+def config_list(option):
+  try:
+    return run('config', '--get-all', option).split()
+  except subprocess2.CalledProcessError:
+    return []
+
+
+def current_branch():
+  return abbrev('HEAD')
+
+
 def parse_commitrefs(*commitrefs):
   """Returns binary encoded commit hashes for one or more commitrefs.
 
@@ -208,7 +232,7 @@ def parse_commitrefs(*commitrefs):
     * 'cool_branch~2'
   """
   try:
-    return map(binascii.unhexlify, hashes(*commitrefs))
+    return map(binascii.unhexlify, hash_multi(*commitrefs))
   except subprocess2.CalledProcessError:
     raise BadCommitRefException(commitrefs)
 
@@ -231,7 +255,11 @@ def run(*cmd, **kwargs):
   return ret
 
 
-def hashes(*reflike):
+def hash_one(reflike):
+  return run('rev-parse', reflike)
+
+
+def hash_multi(*reflike):
   return run('rev-parse', *reflike).splitlines()
 
 
@@ -249,6 +277,13 @@ def intern_f(f, kind='blob'):
   return ret
 
 
+def tags(*args):
+  for line in run('tag', *args).splitlines():
+    if line.startswith(NO_BRANCH):
+      continue
+    yield line.split()[-1]
+
+
 def tree(treeref, recurse=False):
   """Returns a dict representation of a git tree object.
 
@@ -286,6 +321,14 @@ def tree(treeref, recurse=False):
   return ret
 
 
+def upstream(branch):
+  try:
+    return run('rev-parse', '--abbrev-ref', '--symbolic-full-name',
+               branch+'@{upstream}')
+  except subprocess2.CalledProcessError:
+    return None
+
+
 def mktree(treedict):
   """Makes a git tree object and returns its hash.