From fd966d17436c77b6f06f51f0e01cc5b5266386ee Mon Sep 17 00:00:00 2001
From: daniel <daniel.kinzler@wikimedia.de>
Date: Thu, 18 Oct 2012 19:51:49 +0200
Subject: [PATCH] Make EditPage robust against null content.

This adds some checks to avoid fatal errors due to access
to non-objects.

Change-Id: Ib0e867a9aed50226fa8c6f3af655cd11e7fb83ed
---
 includes/EditPage.php | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/includes/EditPage.php b/includes/EditPage.php
index 4a1e5170f5..697daf0733 100644
--- a/includes/EditPage.php
+++ b/includes/EditPage.php
@@ -940,11 +940,11 @@ class EditPage {
 	 * to the original text of the edit.
 	 *
 	 * This difers from Article::getContent() that when a missing revision is
-	 * encountered the result will be an empty string and not the
+	 * encountered the result will be null and not the
 	 * 'missing-revision' message.
 	 *
 	 * @since 1.19
-	 * @return string
+	 * @return Content|null
 	 */
 	private function getOriginalContent() {
 		if ( $this->section == 'new' ) {
@@ -1074,6 +1074,10 @@ class EditPage {
 		$parserOptions = ParserOptions::newFromUser( $wgUser );
 		$content = $page->getContent( Revision::RAW );
 
+		if ( !$content ) {
+			return $handler->makeEmptyContent();
+		}
+
 		return $content->preloadTransform( $title, $parserOptions );
 	}
 
@@ -1676,19 +1680,21 @@ class EditPage {
 
 		// This is the revision the editor started from
 		$baseRevision = $this->getBaseRevision();
-		if ( is_null( $baseRevision ) ) {
+		$baseContent = $baseRevision ? $baseRevision->getContent() : null;
+
+		if ( is_null( $baseContent ) ) {
 			wfProfileOut( __METHOD__ );
 			return false;
 		}
-		$baseContent = $baseRevision->getContent();
 
 		// The current state, we want to merge updates into it
 		$currentRevision = Revision::loadFromTitle( $db, $this->mTitle );
-		if ( is_null( $currentRevision ) ) {
+		$currentContent = $currentRevision ? $currentRevision->getContent() : null;
+
+		if ( is_null( $currentContent ) ) {
 			wfProfileOut( __METHOD__ );
 			return false;
 		}
-		$currentContent = $currentRevision->getContent();
 
 		$handler = ContentHandler::getForModelID( $baseContent->getModel() );
 
-- 
2.20.1