Ticket #10283: 10283.diff

wp-includes/functions.wp-styles.php

@@ -92 +92 @@
  */
 function wp_style_is( $handle, $list = 'queue' ) {
         global $wp_styles;
-        if ( !is_a($wp_styles, 'WP_Scripts') )
+        if ( !is_a($wp_styles, 'WP_Styles') )
                 $wp_styles = new WP_Styles();
 
         $query = $wp_styles->query( $handle, $list );