From 2521f8b5b98069a176bc891c59e9206c490b68de Mon Sep 17 00:00:00 2001
From: Adam Roses Wight <awight@wikimedia.org>
Date: Sun, 18 May 2014 14:26:17 -0700
Subject: [PATCH] (bug 56849) Deprecate dangerous edittime-based content update
 functions

Existing edit conflict logic relies on second-resolution timestamps,
which can fail in many exciting ways.  This patch provides new support
functions which take an explicit revision ID instead of a timestamp.

No functionality is changed.  Hopefully.

TODO:
* Make use of this code by replacing all edittime and starttime logic
with an explicit baseRevId.

Change-Id: I83cdd4adaaa67f81e933654228eccdc9fcdf9009
---
 includes/Revision.php                   |  1 +
 includes/WikiPage.php                   | 41 +++++++++++++++++++++++--
 tests/phpunit/includes/WikiPageTest.php | 16 ++++++++++
 3 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/includes/Revision.php b/includes/Revision.php
index 86c305764a..c5f3a155ff 100644
--- a/includes/Revision.php
+++ b/includes/Revision.php
@@ -1731,6 +1731,7 @@ class Revision implements IDBAccessObject {
 	 * 50 revisions for the sake of performance.
 	 *
 	 * @since 1.20
+	 * @deprecated since 1.24
 	 *
 	 * @param DatabaseBase|int $db The Database to perform the check on. May be given as a
 	 *        Database object or a database identifier usable with wfGetDB.
diff --git a/includes/WikiPage.php b/includes/WikiPage.php
index 8fe948b31b..676d8d5d84 100644
--- a/includes/WikiPage.php
+++ b/includes/WikiPage.php
@@ -1387,6 +1387,8 @@ class WikiPage implements Page, IDBAccessObject {
 	 * If the given revision is newer than the currently set page_latest,
 	 * update the page record. Otherwise, do nothing.
 	 *
+	 * @deprecated since 1.24, use updateRevisionOn instead
+	 *
 	 * @param DatabaseBase $dbw
 	 * @param Revision $revision
 	 * @return bool
@@ -1528,11 +1530,45 @@ class WikiPage implements Page, IDBAccessObject {
 	 * @return Content New complete article content, or null if error.
 	 *
 	 * @since 1.21
+	 * @deprecated since 1.24, use replaceSectionAtRev instead
 	 */
 	public function replaceSectionContent( $section, Content $sectionContent, $sectionTitle = '',
 		$edittime = null ) {
 		wfProfileIn( __METHOD__ );
 
+		$baseRevId = null;
+		if ( $edittime && $section !== 'new' ) {
+			$dbw = wfGetDB( DB_MASTER );
+			$rev = Revision::loadFromTimestamp( $dbw, $this->mTitle, $edittime );
+			if ( !$rev ) {
+				wfDebug( __METHOD__ . " given bad revision time for page " .
+					$this->getId() . "; edittime: $edittime)\n" );
+				wfProfileOut( __METHOD__ );
+				return null;
+			}
+			$baseRevId = $rev->getId();
+		}
+
+		wfProfileOut( __METHOD__ );
+		return $this->replaceSectionAtRev( $section, $sectionContent, $sectionTitle, $baseRevId );
+	}
+
+	/**
+	 * @param string|null|bool $section Null/false, a section number (0, 1, 2, T1, T2, ...) or "new".
+	 * @param Content $sectionContent New content of the section.
+	 * @param string $sectionTitle New section's subject, only if $section is "new".
+	 * @param string $baseRevId integer|null
+	 *
+	 * @throws MWException
+	 * @return Content New complete article content, or null if error.
+	 *
+	 * @since 1.24
+	 */
+	public function replaceSectionAtRev( $section, Content $sectionContent,
+		$sectionTitle = '', $baseRevId = null
+	) {
+		wfProfileIn( __METHOD__ );
+
 		if ( strval( $section ) == '' ) {
 			// Whole-page edit; let the whole text through
 			$newContent = $sectionContent;
@@ -1544,11 +1580,12 @@ class WikiPage implements Page, IDBAccessObject {
 			}
 
 			// Bug 30711: always use current version when adding a new section
-			if ( is_null( $edittime ) || $section == 'new' ) {
+			if ( is_null( $baseRevId ) || $section == 'new' ) {
 				$oldContent = $this->getContent();
 			} else {
+				// TODO: try DB_READ first
 				$dbw = wfGetDB( DB_MASTER );
-				$rev = Revision::loadFromTimestamp( $dbw, $this->mTitle, $edittime );
+				$rev = Revision::loadFromId( $dbw, $baseRevId );
 
 				if ( !$rev ) {
 					wfDebug( "WikiPage::replaceSection asked for bogus section (page: " .
diff --git a/tests/phpunit/includes/WikiPageTest.php b/tests/phpunit/includes/WikiPageTest.php
index 37f197515b..78457d2d1a 100644
--- a/tests/phpunit/includes/WikiPageTest.php
+++ b/tests/phpunit/includes/WikiPageTest.php
@@ -817,6 +817,22 @@ more stuff
 		$this->assertEquals( $expected, is_null( $c ) ? null : trim( $c->getNativeData() ) );
 	}
 
+	/**
+	 * @dataProvider dataReplaceSection
+	 * @covers WikiPage::replaceSectionAtRev
+	 */
+	public function testReplaceSectionAtRev( $title, $model, $text, $section,
+		$with, $sectionTitle, $expected
+	) {
+		$page = $this->createPage( $title, $text, $model );
+		$baseRevId = $page->getLatest();
+
+		$content = ContentHandler::makeContent( $with, $page->getTitle(), $page->getContentModel() );
+		$c = $page->replaceSectionAtRev( $section, $content, $sectionTitle, $baseRevId );
+
+		$this->assertEquals( $expected, is_null( $c ) ? null : trim( $c->getNativeData() ) );
+	}
+
 	/* @todo FIXME: fix this!
 	public function testGetUndoText() {
 	$this->checkHasDiff3();
-- 
2.20.1