Ticket #37566: 37566.diff

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

@@ -14 +14 @@
                 var canvas = document.createElement( 'canvas' ),
                         context = canvas.getContext && canvas.getContext( '2d' ),
                         stringFromCharCode = String.fromCharCode,
-                        tonedata, tone, tone2;
+                        flag, flag2, tonedata, tone, tone2;
 
                 if ( ! context || ! context.fillText ) {
                         return false;
@@ -40 +40 @@
                                  * to a larger image (4-5KB data URL).
                                  */
                                 context.fillText( stringFromCharCode( 55356, 56806, 55356, 56826 ), 0, 0 );
-                                return canvas.toDataURL().length > 3000;
+                                if ( canvas.toDataURL().length < 3000 ) {
+                                        return false;
+                                }
+
+                                context.clearRect( 0, 0, canvas.width, canvas.height );
+
+                                /*
+                                 * Test for rainbow flag compatibility. As the rainbow flag was added out of sequence with
+                                 * the usual Unicode release cycle, some browsers support it, and some don't, even if their
+                                 * Unicode support is up to date.
+                                 *
+                                 * To test for support, we try to render it, and compare the rendering to how it would look if
+                                 * the browser doesn't render it correctly (white flag emoji + rainbow emoji).
+                                 */
+                                context.fillText( stringFromCharCode( 55356, 57331, 65039, 8205, 55356, 57096 ), 0, 0 );
+                                flag = canvas.toDataURL();
+
+                                context.clearRect( 0, 0, canvas.width, canvas.height );
+
+                                context.fillText( stringFromCharCode( 55356, 57331, 55356, 57096 ), 0, 0 );
+                                flag2 = canvas.toDataURL();
+
+                                return flag !== flag2;
                         case 'diversity':
                                 /*
                                  * This tests if the browser supports the Emoji Diversity specification, by rendering an

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

@@ -180 +180 @@
                                                         return false;
                                         }
 
-                                        if ( settings.supports.everythingExceptFlag && ! /^1f1(?:e[6-9a-f]|f[0-9a-f])-1f1(?:e[6-9a-f]|f[0-9a-f])$/.test( icon ) ) {
-
+                                        if ( settings.supports.everythingExceptFlag
+                                                && ! /^1f1(?:e[6-9a-f]|f[0-9a-f])-1f1(?:e[6-9a-f]|f[0-9a-f])$/.test( icon ) // Country flags
+                                                && ! /^(1f3f3-fe0f-200d-1f308|1f3f4-200d-2620-fe0f)$/.test( icon )          // Rainbow and pirate flags
+                                        ) {
                                                 return false;
                                         }