Ticket #33596: 33596.4.patch

src/wp-admin/js/edit-comments.js

@@ -623 +623 @@
                 var editRow, rowData, act, replyButton, editHeight,
                         t = this,
                         c = $('#comment-' + comment_id),
-                        h = c.height();
+                        h = c.height(),
+                        colspanVal = 0;
 
                 t.close();
                 t.cid = comment_id;
@@ -633 +634 @@
                 action = action || 'replyto';
                 act = 'edit' == action ? 'edit' : 'replyto';
                 act = t.act = act + '-comment';
+                colspanVal = $( 'th:visible, td:visible', c ).length;
 
-                $( 'td', editRow ).attr( 'colspan', $( 'th:visible, td:visible', c ).length );
+                // Be sure it's actually a table and there's a `colspan` value to apply.
+                if ( editRow.hasClass( 'inline-edit-row' ) && 0 !== colspanVal ) {
+                        $( 'td', editRow ).attr( 'colspan', colspanVal );
+                }
 
                 $('#action', editRow).val(act);
                 $('#comment_post_ID', editRow).val(post_id);