Ticket #4910: 4910.003.diff

wp-includes/widgets.php

@@ -210 +210 @@
                 $params = array_merge(array($sidebar), (array) $wp_registered_widgets[$id]['params']);
 
                 // Substitute HTML id and class attributes into before_widget
-                $classname_ = ( is_array($wp_registered_widgets[$id]['classname']) ) ? implode('_', $wp_registered_widgets[$id]['classname']) : $wp_registered_widgets[$id]['classname'];
+                $classname_ = '';
+                foreach ( (array) $wp_registered_widgets[$id]['classname'] as $cn ) {
+                        if ( is_string($cn) )
+                                $classname_ .= '_' . $cn;
+                        elseif ( is_object($cn) )
+                                $classname_ .= '_' . get_class($cn);
+                }
+                $classname_ = ltrim($classname_, '_');
                 $params[0]['before_widget'] = sprintf($params[0]['before_widget'], $id, $classname_);
 
                 if ( is_callable($callback) ) {