Ticket #36157: 36157.patch

src/wp-admin/js/post.js

@@ -147 +147 @@
 }).on( 'after-autosave.update-post-slug', function() {
         // Create slug area only if not already there
         // and the title field was not focused (user was not typing a title) when autosave ran
-        if ( ! $('#edit-slug-box > *').length && ! titleHasFocus ) {
+        if ( 0 !== $('#edit-slug-box > *').length && ! titleHasFocus ) {
                 $.post( ajaxurl, {
                                 action: 'sample-permalink',
                                 post_id: $('#post_ID').val(),