Ticket #47976: 47976.diff

src/wp-includes/general-template.php

@@ -3687 +3687 @@
                 ),
                 'htmlhint'   => array(
                         'tagname-lowercase'        => true,
-                        'attr-lowercase'           => true,
+                        'attr-lowercase'           => false,
                         'attr-value-double-quotes' => false,
                         'doctype-first'            => false,
                         'tag-pair'                 => true,