Issue 2311 - Track remote Git branches when required

ensure_dependencies.py

Index: ensure_dependencies.py
diff --git a/ensure_dependencies.py b/ensure_dependencies.py
index 9f2bcc7b7d8feec57b10e4c6d8b62989171ac8ff..eec44054e5cc12c0b35d484b56e9f8af330726d6 100755
--- a/ensure_dependencies.py
+++ b/ensure_dependencies.py
@@ -97,6 +97,17 @@ class Git():
     return subprocess.check_output(command, cwd=repo).strip()
 
   def pull(self, repo):
+    # First perform a fetch so we have a list of remote branch names
+    subprocess.check_call(["git", "fetch", "--quiet", "origin"], cwd=repo)
+    # Next we need to ensure all remote branches are tracked
+    remotes = subprocess.check_output(["git", "branch", "--remotes"], cwd=repo)
+    for match in re.finditer(r"origin/(\S+)", remotes):

[Sebastian Noack, 2015/05/06 12:18:55]

This regex will match "notorigin/foo" as well. That regex would work correctly:

  re.finditer(r"(?:^|\s)(origin/(\S+))", remotes)

Or maybe even better, you could exclude "HEAD" here as well:

  re.finditer(r"(?:^|\s)(origin/((?!HEAD$)\S+))", s, re.M)

[Sebastian Noack, 2015/05/06 12:45:00]

Alternatively, not using a regex, might result in a little more but easier to
understand code:

  for line in remotes.splitlines():
    if '/' not in line:
      continue
    remote, branch = line.strip().split('/', 1)
    if remote != 'origin' or branch == 'HEAD':
      continue

What do think? I leave it up to you.

[kzar, 2015/05/06 12:51:04]

Done.

[kzar, 2015/05/06 12:51:04]

I will stick with the regexp, one line in the output is "  origin/HEAD ->
origin/master" and so I think the logic would need to be more complex to handle
that.

+      remote, local = match.group(0), match.group(1)

[Sebastian Noack, 2015/05/06 12:18:55]

With the regex suggested above, you can simply call match.groups() here:

  remote, local = match.groups()

[kzar, 2015/05/06 12:51:04]

Done.

+      if local != "HEAD":
+        with open(os.devnull, "w") as devnull:

[Sebastian Noack, 2015/05/06 12:18:55]

Nit: Please use "wb", no need to have newlines unified here on Windows.

[kzar, 2015/05/06 12:51:04]

Done.

+          subprocess.call(["git", "branch", "--track", local, remote],
+                          cwd=repo, stdout=devnull, stderr=devnull)
+    # Finally we need to actually fetch all the remote branches and tags
     subprocess.check_call(["git", "fetch", "--quiet", "--all", "--tags"], cwd=repo)

[Sebastian Noack, 2015/05/06 12:18:55]

Please specify "origin" instead "--all" here like above.

[Sebastian Noack, 2015/05/06 12:18:55]

If you move the --tags option to the first "git fetch" call, you could make this
one conditional, skipping it when no new branches were marked as tracking. This
would speedup Git.pull() by factor 2 in the common case.

[kzar, 2015/05/06 12:51:04]

Done.

 
   def update(self, repo, rev):