Merge ~ilasc/turnip:bug-1878669 into turnip:master

[Ioana Lasc]

Don't send MP URL for branch deletion.

Proposed fix for bug-1878669.
For deleted branches the new sha will be received in the post-receive hook with all zeros.
In this case we do not send the MP URL.

[Colin Watson (cjwatson)]

review: Approve

diff --git a/turnip/pack/hooks/hook.py b/turnip/pack/hooks/hook.py
index 61740c4..e135395 100755
--- a/turnip/pack/hooks/hook.py
+++ b/turnip/pack/hooks/hook.py
@@ -146,11 +146,15 @@ def check_ref_permissions(sock, rpc_key, ref_paths):
 
 
 def send_mp_url(received_line):
-    ref = received_line.rstrip(b'\n').split(b' ', 2)[2]
+    _, new_sha, ref = received_line.rstrip(b'\n').split(b' ', 2)
 
-    # check for branch ref here (we're interested in
-    # heads and not tags)
+    # The new sha will be zero when deleting branch
+    # in which case we do not want to send the MP URL.
+    if new_sha == GIT_OID_HEX_ZERO:
+        return
 
+    # Check for branch ref here - we're interested in
+    # heads and not tags.
     if ref.startswith(b'refs/heads/') and not is_default_branch(ref):
         pushed_branch = ref[len(b'refs/heads/'):]
         if not is_default_branch(pushed_branch):
diff --git a/turnip/pack/tests/test_hooks.py b/turnip/pack/tests/test_hooks.py
index cc785d8..449b9f9 100644
--- a/turnip/pack/tests/test_hooks.py
+++ b/turnip/pack/tests/test_hooks.py
@@ -306,6 +306,19 @@ class TestPostReceiveHook(HookTestMixin, TestCase):
         finally:
             os.chdir(curdir)
 
+    @defer.inlineCallbacks
+    def test_no_merge_proposal_URL_delete_branch(self):
+        # No MP URL received for delete of non default branch
+        curdir = os.getcwd()
+        try:
+            os.chdir(self.repo_dir)
+            yield self.assertAccepted([(
+                b'pushed_branch',
+                self.old_sha1, pygit2.GIT_OID_HEX_ZERO)],
+                {b'pushed_branch': ['force_push']})
+        finally:
+            os.chdir(curdir)
+
 
 class TestUpdateHook(TestCase):
     """Tests for the git update hook"""