Multisite: Allow to set the site language of a new site to English.

An empty string in `WPLANG` is used to define the site language as `en_US`. The `! empty()` check didn't catch this case so that `wpmu_create_blog()` fell back to the network setting.

Fixes #36918.
Built from https://develop.svn.wordpress.org/trunk@38655


git-svn-id: http://core.svn.wordpress.org/trunk@38598 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/network/site-new.php

@@ -65,10 +65,14 @@
 	);
 
 	// Handle translation install for the new site.
-	if ( ! empty( $_POST['WPLANG'] ) && wp_can_install_language_pack() ) {
-		$language = wp_download_language_pack( wp_unslash( $_POST['WPLANG'] ) );
-		if ( $language ) {
-			$meta['WPLANG'] = $language;
+	if ( isset( $_POST['WPLANG'] ) ) {
+		if ( '' === $_POST['WPLANG'] ) {
+			$meta['WPLANG'] = ''; // en_US
+		} elseif ( wp_can_install_language_pack() ) {
+			$language = wp_download_language_pack( wp_unslash( $_POST['WPLANG'] ) );
+			if ( $language ) {
+				$meta['WPLANG'] = $language;
+			}
 		}
 	}
 

wp-includes/ms-functions.php

@@ -1092,7 +1092,10 @@ function wpmu_create_user( $user_name, $password, $email ) {
  * @return int|WP_Error Returns WP_Error object on failure, int $blog_id on success
  */
 function wpmu_create_blog( $domain, $path, $title, $user_id, $meta = array(), $site_id = 1 ) {
-	$defaults = array( 'public' => 0 );
+	$defaults = array(
+		'public' => 0,
+		'WPLANG' => get_site_option( 'WPLANG' ),
+	);
 	$meta = wp_parse_args( $meta, $defaults );
 
 	$domain = preg_replace( '/\s+/', '', sanitize_user( $domain, true ) );
@@ -1130,7 +1133,6 @@ function wpmu_create_blog( $domain, $path, $title, $user_id, $meta = array(), $s
 			update_option( $key, $value );
 	}
 
-	add_option( 'WPLANG', get_site_option( 'WPLANG' ) );
 	update_option( 'blog_public', (int) $meta['public'] );
 
 	if ( ! is_super_admin( $user_id ) && ! get_user_meta( $user_id, 'primary_blog', true ) )

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38654';
+$wp_version = '4.7-alpha-38655';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.