From 1b1b3cdb5438e4b649e425e0334c3a72bfca0598 Mon Sep 17 00:00:00 2001
From: Kunal Mehta <legoktm@member.fsf.org>
Date: Mon, 25 Jul 2016 19:56:16 -0700
Subject: [PATCH] Move MediaHandler defaults out of global scope

The defaults that were in $wgMediaHandlers are now listed in
MediaHandlerFactory.

The main advantage of doing this is we get O(1) replacement when
extensions set a media handler in their extension.json.

Bug: T141305
Change-Id: I05771a673837ab8d6331eedc24eb707be7f3a250
---
 includes/DefaultSettings.php           | 19 ++++-------------
 includes/media/MediaHandlerFactory.php | 29 ++++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 1e6030226c..27fdd90fd7 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -941,22 +941,11 @@ $wgTrustedMediaFormats = [
 /**
  * Plugins for media file type handling.
  * Each entry in the array maps a MIME type to a class name
+ *
+ * Core media handlers are listed in MediaHandlerFactory,
+ * and extensions should use extension.json.
  */
-$wgMediaHandlers = [
-	'image/jpeg' => 'JpegHandler',
-	'image/png' => 'PNGHandler',
-	'image/gif' => 'GIFHandler',
-	'image/tiff' => 'TiffHandler',
-	'image/webp' => 'WebPHandler',
-	'image/x-ms-bmp' => 'BmpHandler',
-	'image/x-bmp' => 'BmpHandler',
-	'image/x-xcf' => 'XCFHandler',
-	'image/svg+xml' => 'SvgHandler', // official
-	'image/svg' => 'SvgHandler', // compat
-	'image/vnd.djvu' => 'DjVuHandler', // official
-	'image/x.djvu' => 'DjVuHandler', // compat
-	'image/x-djvu' => 'DjVuHandler', // compat
-];
+$wgMediaHandlers = [];
 
 /**
  * Plugins for page content model handling.
diff --git a/includes/media/MediaHandlerFactory.php b/includes/media/MediaHandlerFactory.php
index c6b4e8dbdc..1deecd7b09 100644
--- a/includes/media/MediaHandlerFactory.php
+++ b/includes/media/MediaHandlerFactory.php
@@ -29,14 +29,39 @@
 class MediaHandlerFactory {
 
 	/**
+	 * Default, MediaWiki core media handlers
+	 *
+	 * @var array
+	 */
+	private static $coreHandlers = [
+		'image/jpeg' => JpegHandler::class,
+		'image/png' => PNGHandler::class,
+		'image/gif' => GIFHandler::class,
+		'image/tiff' => TiffHandler::class,
+		'image/webp' => WebPHandler::class,
+		'image/x-ms-bmp' => BmpHandler::class,
+		'image/x-bmp' => BmpHandler::class,
+		'image/x-xcf' => XCFHandler::class,
+		'image/svg+xml' => SvgHandler::class, // official
+		'image/svg' => SvgHandler::class, // compat
+		'image/vnd.djvu' => DjVuHandler::class, // official
+		'image/x.djvu' => DjVuHandler::class, // compat
+		'image/x-djvu' => DjVuHandler::class, // compat
+	];
+
+	/**
+	 * Instance cache of MediaHandler objects by mimetype
+	 *
 	 * @var MediaHandler[]
 	 */
 	private $handlers;
 
 	protected function getHandlerClass( $type ) {
 		global $wgMediaHandlers;
-		if ( isset( $wgMediaHandlers[$type] ) ) {
-			return $wgMediaHandlers[$type];
+
+		$registry = $wgMediaHandlers + self::$coreHandlers;
+		if ( isset( $registry[$type] ) ) {
+			return $registry[$type];
 		} else {
 			return false;
 		}
-- 
2.20.1