From 76b54ce0a9af112bac2fb0498d9d44532b46f2d5 Mon Sep 17 00:00:00 2001
From: epriestley <git@epriestley.com>
Date: Wed, 4 Oct 2017 08:22:10 -0700
Subject: [PATCH] Fix parsing of Git branches with common and useful name "0"

Summary: See <https://discourse.phabricator-community.org/t/arc-has-a-spurious-failure-on-arc-diff/521>. Oh, PHP!

Test Plan: Created a branch named "0", ran `arc diff`. Before: fatal. After: this beautiful revision.

Reviewers: amckinley

Reviewed By: amckinley

Differential Revision: https://secure.phabricator.com/D18678
---
 src/repository/api/ArcanistGitAPI.php | 8 ++++++--
 src/workflow/ArcanistLandWorkflow.php | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/repository/api/ArcanistGitAPI.php b/src/repository/api/ArcanistGitAPI.php
index a316093e..d1406096 100644
--- a/src/repository/api/ArcanistGitAPI.php
+++ b/src/repository/api/ArcanistGitAPI.php
@@ -497,6 +497,10 @@ final class ArcanistGitAPI extends ArcanistRepositoryAPI {
       return null;
     }
 
+    if (!strlen($branch)) {
+      return null;
+    }
+
     return $branch;
   }
 
@@ -509,7 +513,7 @@ final class ArcanistGitAPI extends ArcanistRepositoryAPI {
       // Verify this, and strip it.
       $ref = rtrim($stdout);
       $branch = $this->getBranchNameFromRef($ref);
-      if (!$branch) {
+      if ($branch === null) {
         throw new Exception(
           pht('Failed to parse %s output!', 'git symbolic-ref'));
       }
@@ -1015,7 +1019,7 @@ final class ArcanistGitAPI extends ArcanistRepositoryAPI {
       list($ref, $hash, $epoch, $tree, $desc, $text) = $fields;
 
       $branch = $this->getBranchNameFromRef($ref);
-      if ($branch) {
+      if ($branch !== null) {
         $result[] = array(
           'current' => ($branch === $current),
           'name' => $branch,
diff --git a/src/workflow/ArcanistLandWorkflow.php b/src/workflow/ArcanistLandWorkflow.php
index 5f13683a..b3c2b181 100644
--- a/src/workflow/ArcanistLandWorkflow.php
+++ b/src/workflow/ArcanistLandWorkflow.php
@@ -444,7 +444,7 @@ EOTEXT
     $branch = $this->getArgument('branch');
     if (empty($branch)) {
       $branch = $this->getBranchOrBookmark();
-      if ($branch) {
+      if ($branch !== null) {
         $this->branchType = $this->getBranchType($branch);
 
         // TODO: This message is misleading when landing a detached head or