commit 3396e57b52ea355f2708fe69bcac249fdd972fe8
author Dave Borowitz <dborowitz@google.com> Mon Apr 17 16:57:17 2017 -0400
committer Dave Borowitz <dborowitz@google.com> Mon Apr 17 17:01:49 2017 -0400
tree f8602ddcb3b876a5f3f4dbaf45806314cde108de
parent 6115562f9577215d83f7f1dd1dc8b9cec54be69a

Disable ReindexAfterRefUpdate in tests

This functionality causes a race during tests that may cause flaky
failures. Specifically, in the case of
ChangeIT#abandonAndRestoreAllowedWithPermission:

1. ACL grant on the main thread (A) modifies refs/meta/config, which
   triggers ReindexAfterRefUpdate, which kicks off a background task
   (thread B) to search for and reindex affected changes.
2. B reads change from primary storage, observes that it is open, and
   constructs a document.
3. A abandons the change, saves the result in primary storage.
4. A indexes the change, deleting it from the open index and adding it
   to the closed index.
5. B indexes the document it constructed in (2), adding it to the open
   index.
6. A attempts to look up the change, finds it in both the open and
   closed indexes, and explodes.

Turning off auto-reindexing causes tests to pass.

The race still exists in running servers, although in practice the
inconsistent cases are fleeting and the index should usually end up in a
consistent state. More details and reflections are in the bug.

Bug: Issue 5944
Change-Id: Ifca5a1065852db38a562755b652fad3de3672816