Customizer: Register controls and settings for `nav_menu_locations` even when there are no menus yet.

This change ensures that the first menu created can be assigned to a location without first saving and reloading the Customizer.

Props markoheijnen.
Fixes #32858.

Built from https://develop.svn.wordpress.org/trunk@33094


git-svn-id: http://core.svn.wordpress.org/trunk@33065 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/customize-nav-menus.js

@@ -2545,6 +2545,7 @@
 	 * @returns {string}
 	 */
 	function displayNavMenuName( name ) {
+		name = name || '';
 		name = $( '<div>' ).text( name ).html(); // Emulate esc_html() which is used in wp-admin/nav-menus.php.
 		name = $.trim( name );
 		return name || api.Menus.data.l10n.unnamed;

wp-includes/class-wp-customize-nav-menus.php

@@ -433,8 +433,6 @@ final class WP_Customize_Nav_Menus {
 			'description' => $description,
 		) );
 
-		// @todo if ( ! $menus ) : make a "default" menu
-		if ( $menus ) {
 		$choices = array( '0' => __( '— Select —' ) );
 		foreach ( $menus as $menu ) {
 			$choices[ $menu->term_id ] = wp_html_excerpt( $menu->name, 40, '…' );
@@ -464,7 +462,6 @@ final class WP_Customize_Nav_Menus {
 				'choices'     => $choices,
 			) ) );
 		}
-		}
 
 		// Register each menu as a Customizer section, and add each menu item to each menu.
 		foreach ( $menus as $menu ) {

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.3-beta1-33093';
+$wp_version = '4.3-beta1-33094';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.