From 6937d389472d63fe3fb251cbf733f8d21ba33950 Mon Sep 17 00:00:00 2001
From: epriestley <git@epriestley.com>
Date: Mon, 4 May 2020 15:42:30 -0700
Subject: [PATCH] Fix an initialization issue in VectorTree

Summary: Ref T13520. In unusual cases where there are no changes in a changeset list (e.g., empty commits) we can fatal when trying to iterate over an empty list of vectors.

Test Plan:
  - Created an empty commit.
  - Used "git show | pbcopy" to create a diff from it.
  - Viewed it in the web UI.
  - Before: fatal when iterating on `null`.
  - After: clean page.

Maniphest Tasks: T13520

Differential Revision: https://secure.phabricator.com/D21221
---
 src/difference/ArcanistDiffVectorTree.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/difference/ArcanistDiffVectorTree.php b/src/difference/ArcanistDiffVectorTree.php
index f0a3b72d..8573b939 100644
--- a/src/difference/ArcanistDiffVectorTree.php
+++ b/src/difference/ArcanistDiffVectorTree.php
@@ -3,7 +3,7 @@
 final class ArcanistDiffVectorTree
   extends Phobject {
 
-  private $vectors;
+  private $vectors = array();
 
   public function addVector(array $vector) {
     $this->vectors[] = $vector;