Ticket #29165: 29165.3.diff

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

@@ -134 +134 @@
                                  * @param WP_Customize_Setting $this WP_Customize_Setting instance.
                                  */
                                 do_action( 'customize_preview_' . $this->id, $this );
+
+                                /**
+                                 * Fires when the {@see WP_Customize_Setting::preview()} method is called for settings
+                                 * not handled as theme_mods or options.
+                                 *
+                                 * The dynamic portion of the hook name, $this->type, refers to the setting type.
+                                 *
+                                 * @since 4.1.0
+                                 *
+                                 * @param WP_Customize_Setting $this WP_Customize_Setting instance.
+                                 */
+                                do_action( "customize_preview_{$this->type}", $this );
                 }
         }