From ffbc7aae62c308cf1f22811474dac1d7c676ae8c Mon Sep 17 00:00:00 2001
From: Andrew Gallagher <agallagher@fb.com>
Date: Mon, 6 Jun 2011 20:57:04 -0700
Subject: [PATCH] arc amend: fix failure when amending merge commit

Summary:
The amend process used "git log HEAD^..HEAD" to get log for the
commit being amended.  When run on a merge commit this can return
any number of commits from the non-first parents.  Since only a
single commit was expected, arc fails here.

This diff changes the amend process to use the '--first-parent' flag
to be consistent with using '^', which references the first parent.
This should guarantee a single commit log every time.

Test Plan:
arc amend on a merge commit

Reviewed By: epriestley
Reviewers: epriestley, jungejason
CC: aran, epriestley, andrewjcg
Differential Revision: 415
---
 src/repository/api/git/ArcanistGitAPI.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/repository/api/git/ArcanistGitAPI.php b/src/repository/api/git/ArcanistGitAPI.php
index 1df02444..baedd1e6 100644
--- a/src/repository/api/git/ArcanistGitAPI.php
+++ b/src/repository/api/git/ArcanistGitAPI.php
@@ -137,7 +137,7 @@ class ArcanistGitAPI extends ArcanistRepositoryAPI {
         $this->getPath());
     } else {
       list($stdout) = execx(
-        '(cd %s; git log --format=medium %s..HEAD)',
+        '(cd %s; git log --first-parent --format=medium %s..HEAD)',
         $this->getPath(),
         $this->getRelativeCommit());
     }