Ticket #37817: 37817.2.diff

src/wp-includes/js/wp-emoji-loader.js

@@ -1 +1 @@
 ( function( window, document, settings ) {
         var src, ready, ii, tests;
 
+        /*
+         * Create a canvas element for testing native browser support
+         * of emoji.
+         */
+        var canvas = document.createElement( 'canvas' );
+        var context = canvas.getContext && canvas.getContext( '2d' );
+
         /**
          * Detect if the browser supports rendering emoji or flag emoji. Flag emoji are a single glyph
          * made of two characters, so some browsers (notably, Firefox OS X) don't support them.
          *
          * @since 4.2.0
          *
-         * @param type {String} Whether to test for support of "simple", "flag", "diversity" or "unicode8" emoji.
+         * @param type {String} Whether to test for support of "flag" or "emoji4" emoji.
          * @return {Boolean} True if the browser can render emoji, false if it cannot.
          */
         function browserSupportsEmoji( type ) {
-                var canvas = document.createElement( 'canvas' ),
-                        context = canvas.getContext && canvas.getContext( '2d' ),
-                        stringFromCharCode = String.fromCharCode,
-                        flag, flag2, tonedata, tone, tone2, technologist, technologist2;
+                var stringFromCharCode = String.fromCharCode,
+                        flag, flag2, technologist, technologist2;
 
                 if ( ! context || ! context.fillText ) {
                         return false;
                 }
 
+                // Cleanup from previous test.
+                context.clearRect( 0, 0, canvas.width, canvas.height );
+
                 /*
                  * Chrome on OS X added native emoji rendering in M41. Unfortunately,
                  * it doesn't work when the font is bolder than 500 weight. So, we
@@ -33 +41 @@
                                 /*
                                  * This works because the image will be one of three things:
                                  * - Two empty squares, if the browser doesn't render emoji
-                                 * - Two squares with 'A' and 'U' in them, if the browser doesn't render flag emoji
-                                 * - The Australian flag
+                                 * - Two squares with 'U' and 'N' in them, if the browser doesn't render flag emoji
+                                 * - The United Nations flag
                                  *
                                  * The first two will encode to small images (1-2KB data URLs), the third will encode
                                  * to a larger image (4-5KB data URL).
                                  */
-                                context.fillText( stringFromCharCode( 55356, 56806, 55356, 56826 ), 0, 0 );
+                                context.fillText( stringFromCharCode( 55356, 56826, 55356, 56819 ), 0, 0 );
                                 if ( canvas.toDataURL().length < 3000 ) {
                                         return false;
                                 }
@@ -63 +71 @@
                                 flag2 = canvas.toDataURL();
 
                                 return flag !== flag2;
-                        case 'diversity':
-                                /*
-                                 * This tests if the browser supports the Emoji Diversity specification, by rendering an
-                                 * emoji with no skin tone specified (in this case, Santa). It then adds a skin tone, and
-                                 * compares if the emoji rendering has changed.
-                                 */
-                                context.fillText( stringFromCharCode( 55356, 57221 ), 0, 0 );
-                                tonedata = context.getImageData( 16, 16, 1, 1 ).data;
-                                tone = tonedata[0] + ',' + tonedata[1] + ',' + tonedata[2] + ',' + tonedata[3];
-
-                                context.fillText( stringFromCharCode( 55356, 57221, 55356, 57343 ), 0, 0 );
-                                // Chrome has issues comparing arrays, and Safari has issues converting arrays to strings.
-                                // So, we create our own string and compare that, instead.
-                                tonedata = context.getImageData( 16, 16, 1, 1 ).data;
-                                tone2 = tonedata[0] + ',' + tonedata[1] + ',' + tonedata[2] + ',' + tonedata[3];
-
-                                return tone !== tone2;
-                        case 'simple':
-                                /*
-                                 * This creates a smiling emoji, and checks to see if there is any image data in the
-                                 * center pixel. In browsers that don't support emoji, the character will be rendered
-                                 * as an empty square, so the center pixel will be blank.
-                                 */
-                                context.fillText( stringFromCharCode( 55357, 56835 ), 0, 0 );
-                                return context.getImageData( 16, 16, 1, 1 ).data[0] !== 0;
-                        case 'unicode8':
-                                /*
-                                 * To check for Unicode 8 support, let's try rendering the most important advancement
-                                 * that the Unicode Consortium have made in years: the burrito.
-                                 */
-                                context.fillText( stringFromCharCode( 55356, 57135 ), 0, 0 );
-                                return context.getImageData( 16, 16, 1, 1 ).data[0] !== 0;
-                        case 'unicode9':
-                                /*
-                                 * Do Unicode 9 emoji render?
-                                 * ¯\_(ツ)_/¯
-                                 */
-                                context.fillText( stringFromCharCode( 55358, 56631 ), 0, 0 );
-                                return context.getImageData( 16, 16, 1, 1 ).data[0] !== 0;
                         case 'emoji4':
                                 /*
                                  * Emoji 4 has the best technologists. So does WordPress!
@@ -128 +97 @@
                 var script = document.createElement( 'script' );
 
                 script.src = src;
-                script.type = 'text/javascript';
+                script.defer = script.type = 'text/javascript';
                 document.getElementsByTagName( 'head' )[0].appendChild( script );
         }
 
-        tests = Array( 'simple', 'flag', 'unicode8', 'diversity', 'unicode9', 'emoji4' );
+        tests = Array( 'flag', 'emoji4' );
 
         settings.supports = {
                 everything: true,