Ticket #24225: 24225.6.diff

src/wp-admin/includes/media.php

@@ -200 +200 @@
         // Convert any remaining line breaks to <br>.
         $caption = preg_replace( '/[ \n\t]*\n[ \t]*/', '<br />', $caption );
 
-        $html = preg_replace( '/(class=["\'][^\'"]*)align(none|left|right|center)\s?/', '$1', $html );
+        $html = preg_replace( '/(class=(["\'])([^\'"]|(?!\2).)*?)align(none|left|right|center)\s?/', '$1', $html );
         if ( empty($align) )
                 $align = 'none';