Add tag write access to merge script.

tools/push-to-trunk/git_recipes.py

Index: tools/push-to-trunk/git_recipes.py
diff --git a/tools/push-to-trunk/git_recipes.py b/tools/push-to-trunk/git_recipes.py
index a1e6256df29db1b26e7ea5676f584c72700e39d5..8944f7ca092d80b06451f358e8f2df2f8165f599 100644
--- a/tools/push-to-trunk/git_recipes.py
+++ b/tools/push-to-trunk/git_recipes.py
@@ -101,6 +101,18 @@ class GitRecipesMixin(object):
   def GitBranch(self, **kwargs):
     return self.Git("branch", **kwargs)
 
+  @Strip
+  def GitRemoteContains(self, hsh, **kwargs):

[agable, 2014/09/29 09:49:12]

I'd be scared that someone might use this who doesn't fully understand it -- it
only looks at local remote-tracking branches, not actually at what is in the
remote server. So it's useless without a fetch first.

[Michael Achenbach, 2014/09/29 10:46:25]

I'll rename the function as it should be just used to determine the remote
branch's name, not for actually verifying a commit on a remote server.

+    """Returns the remote branch for a given commit.
+
+    Returns an empty string in case the commit doesn't exist on any remote

[agable, 2014/09/29 09:49:11]

None is a better sentinel value than "".

[Michael Achenbach, 2014/09/29 10:46:25]

Done. Was because of the @Strip wrapper. But I make that more robust.

+    branch.
+    Returns the last remote branch in case the commit exists on more than one.
+    """
+    branches = self.Git(MakeArgs(["branch -r --contains", hsh]),
+                        **kwargs).strip().splitlines()
+    return (branches or [""])[-1]
+
   def GitCreateBranch(self, name, branch="", **kwargs):
     assert name
     self.Git(MakeArgs(["checkout -b", name, branch]), **kwargs)