From c6a889acc41a119290fc68d5263f92075c9d100c Mon Sep 17 00:00:00 2001
From: Alexandre Emsenhuber <ialex.wiki@gmail.com>
Date: Sun, 10 Mar 2013 16:23:46 +0100
Subject: [PATCH] Don't use isset() to check whether an existing variable is
 null

Change-Id: Ie63f060fb7928fd51a8ad71293955f923f6a18c3
---
 includes/ImagePage.php | 4 ++--
 includes/Import.php    | 2 +-
 includes/Linker.php    | 2 +-
 includes/MimeMagic.php | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/includes/ImagePage.php b/includes/ImagePage.php
index 998d60745d..086b4dd84d 100644
--- a/includes/ImagePage.php
+++ b/includes/ImagePage.php
@@ -108,7 +108,7 @@ class ImagePage extends Article {
 		$diff = $request->getVal( 'diff' );
 		$diffOnly = $request->getBool( 'diffonly', $this->getContext()->getUser()->getOption( 'diffonly' ) );
 
-		if ( $this->getTitle()->getNamespace() != NS_FILE || ( isset( $diff ) && $diffOnly ) ) {
+		if ( $this->getTitle()->getNamespace() != NS_FILE || ( $diff !== null && $diffOnly ) ) {
 			parent::view();
 			return;
 		}
@@ -116,7 +116,7 @@ class ImagePage extends Article {
 		$this->loadFile();
 
 		if ( $this->getTitle()->getNamespace() == NS_FILE && $this->mPage->getFile()->getRedirected() ) {
-			if ( $this->getTitle()->getDBkey() == $this->mPage->getFile()->getName() || isset( $diff ) ) {
+			if ( $this->getTitle()->getDBkey() == $this->mPage->getFile()->getName() || $diff !== null ) {
 				// mTitle is the same as the redirect target so ask Article
 				// to perform the redirect for us.
 				$request->setVal( 'diffonly', 'true' );
diff --git a/includes/Import.php b/includes/Import.php
index 15e6620556..78f77a1f05 100644
--- a/includes/Import.php
+++ b/includes/Import.php
@@ -1646,7 +1646,7 @@ class ImportStreamSource {
 	static function newFromUpload( $fieldname = "xmlimport" ) {
 		$upload =& $_FILES[$fieldname];
 
-		if( !isset( $upload ) || !$upload['name'] ) {
+		if( $upload === null || !$upload['name'] ) {
 			return Status::newFatal( 'importnofile' );
 		}
 		if( !empty( $upload['error'] ) ) {
diff --git a/includes/Linker.php b/includes/Linker.php
index a9bf93428c..d5b3b2f9d6 100644
--- a/includes/Linker.php
+++ b/includes/Linker.php
@@ -616,7 +616,7 @@ class Linker {
 
 			if ( isset( $fp['thumbnail'] ) || isset( $fp['framed'] ) || isset( $fp['frameless'] ) || !$hp['width'] ) {
 				global $wgThumbLimits, $wgThumbUpright;
-				if ( !isset( $widthOption ) || !isset( $wgThumbLimits[$widthOption] ) ) {
+				if ( $widthOption === null || !isset( $wgThumbLimits[$widthOption] ) ) {
 					$widthOption = User::getDefaultOption( 'thumbsize' );
 				}
 
diff --git a/includes/MimeMagic.php b/includes/MimeMagic.php
index 226b0b186c..72bb4c6f56 100644
--- a/includes/MimeMagic.php
+++ b/includes/MimeMagic.php
@@ -346,7 +346,7 @@ class MimeMagic {
 	 * @return MimeMagic
 	 */
 	public static function &singleton() {
-		if ( !isset( self::$instance ) ) {
+		if ( self::$instance === null ) {
 			self::$instance = new MimeMagic;
 		}
 		return self::$instance;
-- 
2.20.1