Ticket #31163: 31163.patch

src/wp-admin/js/editor-expand.js

@@ -323 +323 @@
                         var windowPos = $window.scrollTop(),
                                 type = event && event.type,
                                 resize = type !== 'scroll',
-                                visual = ( mceEditor && ! mceEditor.isHidden() ),
+                                visual = mceEditor && ! mceEditor.isHidden(),
                                 buffer = autoresizeMinHeight,
                                 postBodyTop = $postBody.offset().top,
                                 borderWidth = 1,
@@ -350 +350 @@
                                 topHeight = heights.textTopHeight;
                         }
 
+                        // TinyMCE still intializing.
+                        if ( ! visual && ! $top.length ) {
+                                return;
+                        }
+
                         topPos = $top.parent().offset().top;
                         editorPos = $editor.offset().top;
                         editorHeight = $editor.outerHeight();