From: Brion Vibber <brion@users.mediawiki.org>
Date: Sat, 15 Oct 2011 02:23:22 +0000 (+0000)
Subject: Followup to r99653 (bug 31643) -- reenable client-side thumbnailing of SVGs on Specia... 
X-Git-Tag: 1.31.0-rc.0~27106
X-Git-Url: http://git.cyclocoop.org/%22.%24redirect_annul.%22?a=commitdiff_plain;h=b085bb81d455227d335150ce963d7ba4a58152fb;p=lhc%2Fweb%2Fwiklou.git

Followup to r99653 (bug 31643) -- reenable client-side thumbnailing of SVGs on Special:Upload, with workaround for Firefox 7 regression.

Upstream firefox bug for hang loading some SVGs via data URI: https://bugzilla.mozilla.org/show_bug.cgi?id=694165
A fix may land as soon as Firefox 8.

This rev works around the bug by using window.URL.createObjectURL() instead of loading a data URI via FileReader; the object URL loads more cleanly and doesn't have the same hanging bug.

Needs to be replicated to UploadWizard (or moved to a shared lib!), some other fixes coming so no rush.
---

diff --git a/resources/mediawiki.special/mediawiki.special.upload.js b/resources/mediawiki.special/mediawiki.special.upload.js
index d7b86d78fe..3fc9481a4c 100644
--- a/resources/mediawiki.special/mediawiki.special.upload.js
+++ b/resources/mediawiki.special/mediawiki.special.upload.js
@@ -25,7 +25,7 @@ jQuery( function( $ ) {
 	 * @return boolean
 	 */
 	function fileIsPreviewable( file ) {
-		var	known = ['image/png', 'image/gif', 'image/jpeg'],
+		var	known = ['image/png', 'image/gif', 'image/jpeg', 'image/svg+xml'],
 			tooHuge = 10 * 1024 * 1024;
 		return ( $.inArray( file.type, known ) !== -1 ) && file.size > 0 && file.size < tooHuge;
 	}
@@ -160,20 +160,33 @@ jQuery( function( $ ) {
 	 */
 	function fetchPreview( file, callback, callbackBinary ) {
 		var reader = new FileReader();
-		reader.onload = function() {
-			if ( callbackBinary ) {
-				callbackBinary( reader.result );
-				reader.onload = function() {
-					callback( reader.result );
-				};
-				reader.readAsDataURL( file );
-			} else {
-				callback( reader.result );
-			}
-		};
 		if ( callbackBinary ) {
+			// To fetch JPEG metadata we need a binary string; start there.
+			// todo: 
+			reader.onload = function() {
+				callbackBinary( reader.result );
+
+				// Now run back through the regular code path.
+				fetchPreview(file, callback );
+			};
 			reader.readAsBinaryString( file );
+		} else if ('URL' in window && 'createObjectURL' in window.URL) {
+			// Supported in Firefox 4.0 and above <https://developer.mozilla.org/en/DOM/window.URL.createObjectURL>
+			// WebKit has it in a namespace for now but that's ok. ;)
+			//
+			// Lifetime of this URL is until document close, which is fine
+			// for Special:Upload -- if this code gets used on longer-running
+			// pages, add a revokeObjectURL() when it's no longer needed.
+			//
+			// Prefer this over readAsDataURL for Firefox 7 due to bug reading
+			// some SVG files from data URIs <https://bugzilla.mozilla.org/show_bug.cgi?id=694165>
+			callback(window.URL.createObjectURL(file));
 		} else {
+			// This ends up decoding the file to base-64 and back again, which
+			// feels horribly inefficient.
+			reader.onload = function() {
+				callback( reader.result );
+			};
 			reader.readAsDataURL( file );
 		}
 	}