$( '<p>' ).msg( 'filepageexists', 'File:' + warnings[ 'page-exists' ] ),
{ recoverable: false }
) );
- } else if ( warnings.duplicate !== undefined ) {
- $.each( warnings.duplicate, function ( i, filename ) {
+ } else if ( Array.isArray( warnings.duplicate ) ) {
+ warnings.duplicate.forEach( function ( filename ) {
var $a = $( '<a>' ).text( filename ),
href = mw.Title.makeTitle( mw.config.get( 'wgNamespaceIds' ).file, filename ).getUrl( {} );