Ticket #27620: 27620.2.patch

src/wp-admin/js/customize-controls.js

@@ -195 +195 @@
                                 panels;
 
                         this.uploader = {
+                                // Feature detect browser drag and drop support
+                                canDragAndDrop: function() {
+                                        // this comes directly from Modernizr: http://www.modernizr.com/
+                                        var div = document.createElement('div');
+                                        // IE has support for drag and drop since version 5, but doesn't support dropping files from desktop
+                                        return (('draggable' in div) || ('ondragstart' in div && 'ondrop' in div)) && (mOxie.Env.browser !== 'IE' || mOxie.Env.version > 9);
+                                },
                                 init: function() {
                                         var fallback, button;
 
-                                        if ( this.supports.dragdrop )
+                                        if ( this.canDragAndDrop() ){
                                                 return;
+                                        }
 
                                         // Maintain references while wrapping the fallback button.
                                         fallback = control.container.find( '.upload-fallback' );
                                         button   = fallback.children().detach();
 
+                                        this.dropzone.hide();
                                         this.browser.detach().empty().append( button );
                                         fallback.append( this.browser ).show();
                                 }