# If we just undid one rev, use an autosummary
$firstrev = $oldrev->getNext();
if ( $firstrev && $firstrev->getId() == $undo ) {
- $undoSummary = wfMessage( 'undo-summary', $undo, $undorev->getUserText() )->inContentLanguage()->text();
+ $userText = $undorev->getUserText();
+ if ( $userText === '' ) {
+ $undoSummary = wfMessage(
+ 'undo-summary-username-hidden',
+ $undo
+ )->inContentLanguage()->text();
+ } else {
+ $undoSummary = wfMessage(
+ 'undo-summary',
+ $undo,
+ $userText
+ )->inContentLanguage()->text();
+ }
if ( $this->summary === '' ) {
$this->summary = $undoSummary;
} else {