From 14a172d70743f820e703e2a5db2ad6560daacff4 Mon Sep 17 00:00:00 2001
From: epriestley <epriestley@phabricator.com>
Date: Tue, 15 Mar 2011 14:25:47 -0700
Subject: [PATCH] Make GitDiscovery terminate, maybe?

---
 .../PhabricatorRepositoryGitCommitDiscoveryDaemon.php  | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/applications/repository/daemon/commitdiscovery/git/PhabricatorRepositoryGitCommitDiscoveryDaemon.php b/src/applications/repository/daemon/commitdiscovery/git/PhabricatorRepositoryGitCommitDiscoveryDaemon.php
index 9d8e9e746e..67b0bb5562 100644
--- a/src/applications/repository/daemon/commitdiscovery/git/PhabricatorRepositoryGitCommitDiscoveryDaemon.php
+++ b/src/applications/repository/daemon/commitdiscovery/git/PhabricatorRepositoryGitCommitDiscoveryDaemon.php
@@ -57,6 +57,8 @@ class PhabricatorRepositoryGitCommitDiscoveryDaemon
     $discover[] = $commit;
     $insert[] = $commit;
 
+    $seen_parent = array();
+
     while (true) {
       $target = array_pop($discover);
       list($parents) = execx(
@@ -65,6 +67,14 @@ class PhabricatorRepositoryGitCommitDiscoveryDaemon
         $target);
       $parents = array_filter(explode(' ', trim($parents)));
       foreach ($parents as $parent) {
+        if (isset($seen_parent[$parent])) {
+          // We end up in a loop here somehow when we parse Arcanist if we
+          // don't do this. TODO: Figure out why and draw a pretty diagram
+          // since it's not evident how parsing a DAG with this causes the
+          // loop to stop terminating.
+          continue;
+        }
+        $seen_parent[$parent] = true;
         if (!$this->isKnownCommit($parent)) {
           $discover[] = $parent;
           $insert[] = $parent;