Merge pull request apache#569 from pwendell/merge-fixes.

Fixes bug where merges won't close associated pull request.

Previously we added "Closes #XX" in the title. Github will sometimes
linbreak the title in a way that causes this to not work. This patch
instead adds the line in the body.

This also makes the commit format more concise for merge commits.
We might consider just dropping those in the future.

Author: Patrick Wendell <[email protected]>

Closes apache#569 and squashes the following commits:

732eba1 [Patrick Wendell] Fixes bug where merges won't close associated pull request.

dev/merge_spark_pr.py

@@ -93,18 +93,20 @@ def merge_pr(pr_num, target_ref):
     '--pretty=format:%an <%ae>']).split("\n")
   distinct_authors = sorted(set(commit_authors), key=lambda x: commit_authors.count(x), reverse=True)
   primary_author = distinct_authors[0]
-  commits = run_cmd(['git', 'log', 'HEAD..%s' % pr_branch_name]).split("\n\n")
+  commits = run_cmd(['git', 'log', 'HEAD..%s' % pr_branch_name, 
+    '--pretty=format:%h [%an] %s']).split("\n\n")
 
-  merge_message = "Merge pull request #%s from %s. Closes #%s.\n\n%s\n\n%s" % (
-    pr_num, pr_repo_desc, pr_num, title, body)
+  merge_message = "Merge pull request #%s from %s.\n\n%s\n\n%s" % (
+    pr_num, pr_repo_desc, title, body)
   merge_message_parts = merge_message.split("\n\n")
   merge_message_flags = []
 
   for p in merge_message_parts:
     merge_message_flags = merge_message_flags + ["-m", p]
   authors = "\n".join(["Author: %s" % a for a in distinct_authors])
   merge_message_flags = merge_message_flags + ["-m", authors]
-  merge_message_flags = merge_message_flags + ["-m", "== Merge branch commits =="]
+  merge_message_flags = merge_message_flags + [
+    "-m", "Closes #%s and squashes the following commits:" % pr_num]
   for c in commits:
     merge_message_flags = merge_message_flags + ["-m", c]