Ticket #20871: 20871.7.diff

wp-includes/class-wp-customize-setting.php

@@ -382 +382 @@
  *
  * Results should be properly handled using another setting or callback.
  */
-class WP_Customize_Header_Image_Setting extends WP_Customize_Setting {
+final class WP_Customize_Header_Image_Setting extends WP_Customize_Setting {
         public $id = 'header_image_data';
 
         public function update( $value ) {
@@ -398 +398 @@
                 else
                         $custom_image_header->set_header_image( $value );
         }
-}
- No newline at end of file
+}
+
+final class WP_Customize_Background_Image_Setting extends WP_Customize_Setting {
+        public $id = 'background_image_thumb';
+
+        public function update( $value ) {
+                remove_theme_mod( 'background_image_thumb' );
+        }
+}

wp-includes/class-wp-customize-manager.php

@@ -781 +781 @@
                         'theme_supports' => 'custom-background',
                 ) );
 
+                $this->add_setting( new WP_Customize_Background_Image_Setting( $this, 'background_image_thumb', array(
+                        'theme_supports' => 'custom-background',
+                ) ) );
+
                 $this->add_control( new WP_Customize_Background_Image_Control( $this ) );
 
                 $this->add_setting( 'background_repeat', array(