Index: src/wp-admin/install.php
===================================================================
--- src/wp-admin/install.php	(revision 29656)
+++ src/wp-admin/install.php	(working copy)
@@ -204,6 +204,7 @@
 			$loaded_language = wp_download_language_pack( $langugage );
 			if ( $loaded_language ) {
 				load_default_textdomain( $loaded_language );
+				$GLOBALS['wp_locale'] = new WP_Locale();
 			}
 		}

@@ -221,6 +222,7 @@
 	case 2:
 		if ( ! empty( $langugage ) && load_default_textdomain( $langugage ) ) {
 			$loaded_language = $langugage;
+			$GLOBALS['wp_locale'] = new WP_Locale();
 		} else {
 			$loaded_language = 'en_US';
 		}
Index: src/wp-admin/setup-config.php
===================================================================
--- src/wp-admin/setup-config.php	(revision 29656)
+++ src/wp-admin/setup-config.php	(working copy)
@@ -110,6 +110,7 @@
 			$loaded_language = wp_download_language_pack( $language );
 			if ( $loaded_language ) {
 				load_default_textdomain( $loaded_language );
+				$GLOBALS['wp_locale'] = new WP_Locale();
 			}
 		}

@@ -144,6 +145,8 @@

 	case 1:
 		load_default_textdomain( $language );
+		$GLOBALS['wp_locale'] = new WP_Locale();
+
 		setup_config_display_header();
 	?>
 <form method="post" action="setup-config.php?step=2">
@@ -184,6 +187,8 @@

 	case 2:
 	load_default_textdomain( $language );
+	$GLOBALS['wp_locale'] = new WP_Locale();
+
 	$dbname = trim( wp_unslash( $_POST[ 'dbname' ] ) );
 	$uname = trim( wp_unslash( $_POST[ 'uname' ] ) );
 	$pwd = trim( wp_unslash( $_POST[ 'pwd' ] ) );