Ticket #27538: 27538.5.patch

src/wp-includes/default-widgets.php

@@ -660 +660 @@
         }
 
         function widget($args, $instance) {
-                $cache = wp_cache_get('widget_recent_posts', 'widget');
+                $cache = array();
+                if ( ! $this->is_preview() ) {
+                        $cache = wp_cache_get( 'widget_recent_posts', 'widget' );
+                }
 
-                if ( !is_array($cache) )
+                if ( ! is_array( $cache ) ) {
                         $cache = array();
+                }
 
-                if ( ! isset( $args['widget_id'] ) )
+                if ( ! isset( $args['widget_id'] ) ) {
                         $args['widget_id'] = $this->id;
+                }
 
                 if ( isset( $cache[ $args['widget_id'] ] ) ) {
                         echo $cache[ $args['widget_id'] ];
@@ -723 +728 @@
 
                 endif;
 
-                $cache[$args['widget_id']] = ob_get_flush();
-                wp_cache_set('widget_recent_posts', $cache, 'widget');
+                if ( ! $this->is_preview() ) {
+                        $cache[ $args['widget_id'] ] = ob_get_flush();
+                        wp_cache_set( 'widget_recent_posts', $cache, 'widget' );
+                } else {
+                        ob_flush();
+                }
         }
 
         function update( $new_instance, $old_instance ) {
@@ -807 +816 @@
         function widget( $args, $instance ) {
                 global $comments, $comment;
 
-                $cache = wp_cache_get('widget_recent_comments', 'widget');
-
-                if ( ! is_array( $cache ) )
+                $cache = array();
+                if ( ! $this->is_preview() ) {
+                        $cache = wp_cache_get('widget_recent_comments', 'widget');
+                }
+                if ( ! is_array( $cache ) ) {
                         $cache = array();
+                }
 
                 if ( ! isset( $args['widget_id'] ) )
                         $args['widget_id'] = $this->id;
@@ -865 +877 @@
                 $output .= $after_widget;
 
                 echo $output;
-                $cache[$args['widget_id']] = $output;
-                wp_cache_set('widget_recent_comments', $cache, 'widget');
+
+                if ( ! $this->is_preview() ) {
+                        $cache[ $args['widget_id'] ] = $output;
+                        wp_cache_set( 'widget_recent_comments', $cache, 'widget' );
+                }
         }
 
         function update( $new_instance, $old_instance ) {

src/wp-includes/widgets.php

@@ -163 +163 @@
                 return array($this, 'form_callback');
         }
 
+        /**
+         * Determine if we're in the Customizer; if true, then the object cache gets
+         * suspended and widgets should check this to decide whether they should
+         * store anything persistently to the object cache, to transients, or
+         * anywhere else.
+         *
+         * @return bool
+         */
+        function is_preview() {
+                global $wp_customize;
+                return ( isset( $wp_customize ) && $wp_customize->is_preview() ) ;
+        }
+
         /** Generate the actual widget content.
          *      Just finds the instance and calls widget().
          *      Do NOT over-ride this function. */
@@ -189 +202 @@
                          * @param array     $args     An array of default widget arguments.
                          */
                         $instance = apply_filters( 'widget_display_callback', $instance, $this, $args );
-                        if ( false !== $instance )
-                                $this->widget($args, $instance);
+                        if ( false !== $instance ) {
+                                $was_cache_addition_suspended = wp_suspend_cache_addition();
+                                if ( $this->is_preview() && ! $was_cache_addition_suspended ) {
+                                        wp_suspend_cache_addition( true );
+                                }
+
+                                $this->widget( $args, $instance );
+
+                                if ( $this->is_preview() ) {
+                                        wp_suspend_cache_addition( $was_cache_addition_suspended );
+                                }
+                        }
                 }
         }
 
@@ -241 +264 @@
 
                                 $old_instance = isset($all_instances[$number]) ? $all_instances[$number] : array();
 
+                                $was_cache_addition_suspended = wp_suspend_cache_addition();
+                                if ( $this->is_preview() && ! $was_cache_addition_suspended ) {
+                                        wp_suspend_cache_addition( true );
+                                }
+
                                 $instance = $this->update($new_instance, $old_instance);
 
+                                if ( $this->is_preview() ) {
+                                        wp_suspend_cache_addition( $was_cache_addition_suspended );
+                                }
+
                                 /**
                                  * Filter a widget's settings before saving.
                                  *