From 6daa2b6c2efa7faebd7b9bc084466886fe431b86 Mon Sep 17 00:00:00 2001
From: epriestley <git@epriestley.com>
Date: Mon, 23 Dec 2013 10:43:45 -0800
Subject: [PATCH] Fix a commit hook issue with the initial commit to Mercurial
 repositories

Summary:
Fixes T4257. The `hg heads` command exits with an error code and no output in an empty repository.

Just ignore the error code: we don't have a great way to distinguish between errors, and we ran another `hg` command moments before, so we have at least some confidence it isn't a PATH sort of thing.

Test Plan: Created a new Mercurial repository and pushed to hit the error in T4257. Applied this fix and got a clean push with an accurate push log.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4257

Differential Revision: https://secure.phabricator.com/D7817
---
 .../diffusion/engine/DiffusionCommitHookEngine.php    | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/applications/diffusion/engine/DiffusionCommitHookEngine.php b/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
index 285b4ad57e..667e2013b2 100644
--- a/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
+++ b/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
@@ -583,17 +583,22 @@ final class DiffusionCommitHookEngine extends Phobject {
     // Resolve all of the futures now. We don't need the 'commits' future yet,
     // but it simplifies the logic to just get it out of the way.
     foreach (Futures($futures) as $future) {
-      $future->resolvex();
+      $future->resolve();
     }
 
     list($commit_raw) = $futures['commits']->resolvex();
     $commit_map = $this->parseMercurialCommits($commit_raw);
     $this->mercurialCommits = $commit_map;
 
-    list($old_raw) = $futures['old']->resolvex();
+    // NOTE: `hg heads` exits with an error code and no output if the repository
+    // has no heads. Most commonly this happens on a new repository. We know
+    // we can run `hg` successfully since the `hg log` above didn't error, so
+    // just ignore the error code.
+
+    list($err, $old_raw) = $futures['old']->resolve();
     $old_refs = $this->parseMercurialHeads($old_raw);
 
-    list($new_raw) = $futures['new']->resolvex();
+    list($err, $new_raw) = $futures['new']->resolve();
     $new_refs = $this->parseMercurialHeads($new_raw);
 
     $all_refs = array_keys($old_refs + $new_refs);