From d0b9ffed7601a49233f948ca432558256c01902a Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Mon, 7 Dec 2015 16:26:07 -0800
Subject: [PATCH] Make TitleMoveComplete hook events apply in transactions

* All updates for an event are atomic for the main DB.
* This follows-up 9e51328790c0a by reverting the auto-commit
  behavoir which was a side-effect of that change.
* Added TitleMoveCompleting hook with is a pre-commit version
  of the same hook. Various extension could benefit from the
  atomicity of running in the main transaction.

Change-Id: Ife5990bbedca1de78bcf83f2d6fdeeae8086ffad
---
 RELEASE-NOTES-1.27    |  1 +
 docs/hooks.txt        | 10 +++++++++-
 includes/MovePage.php |  9 ++++++++-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/RELEASE-NOTES-1.27 b/RELEASE-NOTES-1.27
index 77f7e2fffb..b41b8c2ae0 100644
--- a/RELEASE-NOTES-1.27
+++ b/RELEASE-NOTES-1.27
@@ -96,6 +96,7 @@ production.
   authentication extensions.
 * $wgMaxUserDBWriteDuration added to limit huge user-generated transactions.
   Regular web request transactions that takes longer than this are aborted.
+* Added a new hook, 'TitleMoveCompleting', which runs before a page move is committed.
 
 === External library changes in 1.27 ===
 ==== Upgraded external libraries ====
diff --git a/docs/hooks.txt b/docs/hooks.txt
index 7c79e729a5..fe88fa7d56 100644
--- a/docs/hooks.txt
+++ b/docs/hooks.txt
@@ -3030,7 +3030,7 @@ $old: old title
 $nt: new title
 $user: user who does the move
 
-'TitleMoveComplete': After moving an article (title).
+'TitleMoveComplete': After moving an article (title), post-commit.
 &$old: old title
 &$nt: new title
 &$user: user who did the move
@@ -3038,6 +3038,14 @@ $pageid: database ID of the page that's been moved
 $redirid: database ID of the created redirect
 $reason: reason for the move
 
+'TitleMoveCompleting': After moving an article (title), pre-commit.
+$old: old title
+$nt: new title
+$user: user who did the move
+$pageid: database ID of the page that's been moved
+$redirid: database ID of the created redirect
+$reason: reason for the move
+
 'TitleQuickPermissions': Called from Title::checkQuickPermissions to add to
 or override the quick permissions check.
 $title: The Title object being accessed
diff --git a/includes/MovePage.php b/includes/MovePage.php
index 736cd8d650..b91895508a 100644
--- a/includes/MovePage.php
+++ b/includes/MovePage.php
@@ -369,10 +369,17 @@ class MovePage {
 			WatchedItem::duplicateEntries( $this->oldTitle, $this->newTitle );
 		}
 
+		Hooks::run(
+			'TitleMoveCompleting',
+			array( $this->oldTitle, $this->newTitle, $user, $pageid, $redirid, $reason )
+		);
+
 		$dbw->endAtomic( __METHOD__ );
 
 		$params = array( &$this->oldTitle, &$this->newTitle, &$user, $pageid, $redirid, $reason );
-		$dbw->onTransactionIdle( function () use ( $params ) {
+		$dbw->onTransactionIdle( function () use ( $params, $dbw ) {
+			// Keep each single hook handler atomic
+			$dbw->setFlag( DBO_TRX ); // flag is automatically reset by DB layer
 			Hooks::run( 'TitleMoveComplete', $params );
 		} );
 
-- 
2.20.1