Customize: Prevent syncing unmodified settings from controls into preview to guard against triggering an infinite reload due to selective refresh fallback behavior.

If a value is sanitized in PHP and differs from the JS value in the pane, a `change` event for the setting is triggered upon refresh. This should be avoided since the value just came from the server as being sanitized. This also fixes periodic issue where selective refresh happens immediately after a full refresh.

Fixes #37032.

Built from https://develop.svn.wordpress.org/trunk@39112


git-svn-id: http://core.svn.wordpress.org/trunk@39054 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/customize-controls.js

@@ -4299,6 +4299,7 @@
 			var previewer = this, synced = {}, constructs;
 
 			synced.settings = api.get();
+			synced['settings-modified-while-loading'] = previewer.settingsModifiedWhileLoading;
 			if ( 'resolved' !== previewer.deferred.active.state() || previewer.loading ) {
 				synced.scroll = previewer.scroll;
 			}
@@ -4421,7 +4422,7 @@
 		 * Refresh the preview seamlessly.
 		 */
 		refresh: function() {
-			var previewer = this;
+			var previewer = this, onSettingChange;
 
 			// Display loading indicator
 			previewer.send( 'loading-initiated' );
@@ -4435,6 +4436,15 @@
 				container:  previewer.container
 			});
 
+			previewer.settingsModifiedWhileLoading = {};
+			onSettingChange = function( setting ) {
+				previewer.settingsModifiedWhileLoading[ setting.id ] = true;
+			};
+			api.bind( 'change', onSettingChange );
+			previewer.loading.always( function() {
+				api.unbind( 'change', onSettingChange );
+			} );
+
 			previewer.loading.done( function( readyData ) {
 				var loadingFrame = this, previousPreview, onceSynced;
 

wp-includes/js/customize-preview.js

@@ -654,6 +654,25 @@
 		});
 
 		api.preview.bind( 'sync', function( events ) {
+
+			/*
+			 * Delete any settings that already exist locally which haven't been
+			 * modified in the controls while the preview was loading. This prevents
+			 * situations where the JS value being synced from the pane may differ
+			 * from the PHP-sanitized JS value in the preview which causes the
+			 * non-sanitized JS value to clobber the PHP-sanitized value. This
+			 * is particularly important for selective refresh partials that
+			 * have a fallback refresh behavior since infinite refreshing would
+			 * result.
+			 */
+			if ( events.settings && events['settings-modified-while-loading'] ) {
+				_.each( _.keys( events.settings ), function( syncedSettingId ) {
+					if ( api.has( syncedSettingId ) && ! events['settings-modified-while-loading'][ syncedSettingId ] ) {
+						delete events.settings[ syncedSettingId ];
+					}
+				} );
+			}
+
 			$.each( events, function( event, args ) {
 				api.preview.trigger( event, args );
 			});

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-beta1-39111';
+$wp_version = '4.7-beta1-39112';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.