Fix hanging issue with git map-branches.

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index 59e412123fcd73404fddc29c1e6fd0245c66440c..cf29958353055ec8e813000ab775bb17b9b68436 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -15,6 +15,7 @@ import glob
 import httplib
 import json
 import logging
+import multiprocessing
 import optparse
 import os
 import Queue
@@ -1715,7 +1716,11 @@ def get_cl_statuses(
     # Process one branch synchronously to work through authentication, then
     # spawn processes to process all the other branches in parallel.
     if branches:
-      fetch = lambda branch: fetch_cl_status(branch, auth_config=auth_config)
+      def fetch(branch):

[Matt Giuca, 2016/03/31 03:27:20]

This should be at the top of the function (style).

[calamity, 2016/04/01 03:42:24]

I miss the lambda already.

+        if not branch:
+          return None

[Matt Giuca, 2016/03/31 03:27:20]

Blank line after return.

[calamity, 2016/04/01 03:42:24]

Done.

+        return fetch_cl_status(branch, auth_config=auth_config)
+
       yield fetch(branches[0])
 
       branches_to_fetch = branches[1:]
@@ -1723,13 +1728,27 @@ def get_cl_statuses(
           min(max_processes, len(branches_to_fetch))
               if max_processes is not None
               else len(branches_to_fetch))
-      for x in pool.imap_unordered(fetch, branches_to_fetch):
-        yield x
+      x = pool.imap_unordered(fetch, branches_to_fetch).__iter__()
+
+      fetched_branches = set()
+      while True:
+        try:
+          row = x.next(timeout=5)
+          fetched_branches.add(row[0])
+          yield row
+        except multiprocessing.TimeoutError:
+          break
+
+      # Add any branches that failed to fetch.
+      for b in set(branches_to_fetch) - fetched_branches:
+        cl = Changelist(branchref=b, auth_config=auth_config)
+        yield (b, cl.GetIssueURL() if b else None, 'error')
+
   else:
     # Do not use GetApprovingReviewers(), since it requires an HTTP request.
     for b in branches:
       cl = Changelist(branchref=b, auth_config=auth_config)
-      url = cl.GetIssueURL()
+      url = cl.GetIssueURL() if b else None
       yield (b, url, 'waiting' if url else 'error')