Ticket #19845: 19845.3.diff

src/wp-includes/js/tinymce/plugins/wordpress/plugin.js

@@ -443 +443 @@
                 editor.dom.bind( editor.getBody(), 'dragstart', function() {
                         _hideButtons();
                 });
+
+                editor.dom.bind( editor.getWin(), 'dragover', function(e) {
+                        if ( typeof window.jQuery !== 'undefined' ) {
+                                // Propagate the event to its container for the parent window to catch.
+                                jQuery( editor.getContainer() ).trigger(e);
+                        }
+                });
         });
 
         editor.on( 'BeforeExecCommand', function() {