From 840d01d05dace67aede23653c5b32f7ea8e5efaf Mon Sep 17 00:00:00 2001
From: Timo Tijhof <krinklemail@gmail.com>
Date: Thu, 12 Mar 2015 21:15:43 +0100
Subject: [PATCH] Title: Consider empty edit notices to not exist

Don't include edit notices that parse to nothing in the output
array.

Similar filtering logic currently exists in VisualEditor. This
helps support systems like the one on English Wikipedia where an
Editnotice page may exist, but conditionally outputs the actual
notice.

Bug: T91715
Change-Id: Ic8fb038fd6acf18830cafdd09a8ca86f3950c7a5
---
 includes/Title.php | 61 ++++++++++++++++++++++++++--------------------
 1 file changed, 34 insertions(+), 27 deletions(-)

diff --git a/includes/Title.php b/includes/Title.php
index b04bf0436c..f47300cd03 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -4685,15 +4685,18 @@ class Title {
 		$msg = wfMessage( $editnotice_ns );
 		if ( $msg->exists() ) {
 			$html = $msg->parseAsBlock();
-			$notices[$editnotice_ns] = Html::rawElement(
-				'div',
-				array( 'class' => array(
-					'mw-editnotice',
-					'mw-editnotice-namespace',
-					Sanitizer::escapeClass( "mw-$editnotice_ns" )
-				) ),
-				$html
-			);
+			// Edit notices may have complex logic, but output nothing (T91715)
+			if ( trim( $html ) !== '' ) {
+				$notices[$editnotice_ns] = Html::rawElement(
+					'div',
+					array( 'class' => array(
+						'mw-editnotice',
+						'mw-editnotice-namespace',
+						Sanitizer::escapeClass( "mw-$editnotice_ns" )
+					) ),
+					$html
+				);
+			}
 		}
 
 		if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
@@ -4705,15 +4708,17 @@ class Title {
 				$msg = wfMessage( $editnotice_base );
 				if ( $msg->exists() ) {
 					$html = $msg->parseAsBlock();
-					$notices[$editnotice_base] = Html::rawElement(
-						'div',
-						array( 'class' => array(
-							'mw-editnotice',
-							'mw-editnotice-base',
-							Sanitizer::escapeClass( "mw-$editnotice_base" )
-						) ),
-						$html
-					);
+					if ( trim( $html ) !== '' ) {
+						$notices[$editnotice_base] = Html::rawElement(
+							'div',
+							array( 'class' => array(
+								'mw-editnotice',
+								'mw-editnotice-base',
+								Sanitizer::escapeClass( "mw-$editnotice_base" )
+							) ),
+							$html
+						);
+					}
 				}
 			}
 		} else {
@@ -4722,15 +4727,17 @@ class Title {
 			$msg = wfMessage( $editnoticeText );
 			if ( $msg->exists() ) {
 				$html = $msg->parseAsBlock();
-				$notices[$editnoticeText] = Html::rawElement(
-					'div',
-					array( 'class' => array(
-						'mw-editnotice',
-						'mw-editnotice-page',
-						Sanitizer::escapeClass( "mw-$editnoticeText" )
-					) ),
-					$html
-				);
+				if ( trim( $html ) !== '' ) {
+					$notices[$editnoticeText] = Html::rawElement(
+						'div',
+						array( 'class' => array(
+							'mw-editnotice',
+							'mw-editnotice-page',
+							Sanitizer::escapeClass( "mw-$editnoticeText" )
+						) ),
+						$html
+					);
+				}
 			}
 		}
 
-- 
2.20.1