Index: HTMLForm.php
===================================================================
--- HTMLForm.php (revision 63755)
+++ HTMLForm.php (working copy)
@@ -572,7 +572,7 @@
if( !$hasLeftColumn ) // Avoid strange spacing when no labels exist
$classes[] = 'mw-htmlform-nolabel';
$attribs = array(
- 'classes' => implode( ' ', $classes ),
+ 'class' => implode( ' ', $classes ),
);
if ( $sectionName )
$attribs['id'] = Sanitizer::escapeId( "mw-htmlform-$sectionName" );