From 126f66d95547aee888bd06c1307557d340f4a5a5 Mon Sep 17 00:00:00 2001
From: Tyler Anthony Romeo <tylerromeo@gmail.com>
Date: Fri, 17 May 2013 12:10:31 +0000
Subject: [PATCH] Fix return type of MessageCache::getMsgFromNamespace for
 existing

Functions expect the message cache to return a string if a message
exists, even empty, and false if it does not exist. This adds casting
to the substr() function, which would return false for existing
messages that were just blank.

Bug: 14176
Change-Id: Id91914a3701fe53f1e2e894824512489392c628b
---
 RELEASE-NOTES-1.22              |  3 +++
 includes/cache/MessageCache.php | 10 +++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/RELEASE-NOTES-1.22 b/RELEASE-NOTES-1.22
index 4f33548aa1..38b2cbdad5 100644
--- a/RELEASE-NOTES-1.22
+++ b/RELEASE-NOTES-1.22
@@ -143,6 +143,9 @@ production.
 * (bug 48294) API: Fix chunk upload async mode.
 * (bug 46749) Broken files tracking category removed from pages if an image
   with that name is uploaded.
+* (bug 14176) System messages that are empty were previously incorrectly treated
+  as non-existent, causing a fallback to the default. This stopped users from
+  overriding system messages to make them blank.
 
 === API changes in 1.22 ===
 * (bug 46626) xmldoublequote parameter was removed. Because of a bug, the
diff --git a/includes/cache/MessageCache.php b/includes/cache/MessageCache.php
index 7dc8d05b65..fcefc065f1 100644
--- a/includes/cache/MessageCache.php
+++ b/includes/cache/MessageCache.php
@@ -865,14 +865,16 @@ class MessageCache {
 	 *
 	 * @param string $title Message cache key with initial uppercase letter.
 	 * @param string $code Code denoting the language to try.
-	 * @return string|bool False on failure
+	 * @return string|bool The message, or false iff it does not exist or on error
 	 */
 	function getMsgFromNamespace( $title, $code ) {
 		$this->load( $code );
 		if ( isset( $this->mCache[$code][$title] ) ) {
 			$entry = $this->mCache[$code][$title];
 			if ( substr( $entry, 0, 1 ) === ' ' ) {
-				return substr( $entry, 1 );
+				// The message exists, so make sure a string
+				// is returned.
+				return (string)substr( $entry, 1 );
 			} elseif ( $entry === '!NONEXISTENT' ) {
 				return false;
 			} elseif ( $entry === '!TOO BIG' ) {
@@ -895,7 +897,9 @@ class MessageCache {
 		if ( $entry ) {
 			if ( substr( $entry, 0, 1 ) === ' ' ) {
 				$this->mCache[$code][$title] = $entry;
-				return substr( $entry, 1 );
+				// The message exists, so make sure a string
+				// is returned.
+				return (string)substr( $entry, 1 );
 			} elseif ( $entry === '!NONEXISTENT' ) {
 				$this->mCache[$code][$title] = '!NONEXISTENT';
 				return false;
-- 
2.20.1