diff -r f507feede89a -r 09a1c134465b web/wp-includes/class-wp-theme.php
--- a/web/wp-includes/class-wp-theme.php	Wed Dec 19 12:35:13 2012 -0800
+++ b/web/wp-includes/class-wp-theme.php	Wed Dec 19 17:46:52 2012 -0800
@@ -41,6 +41,7 @@
 		'default'      => 'WordPress Default',
 		'twentyten'    => 'Twenty Ten',
 		'twentyeleven' => 'Twenty Eleven',
+		'twentytwelve' => 'Twenty Twelve',
 	);
 
 	/**
@@ -253,6 +254,7 @@
 				// Parent theme is missing.
 				$this->errors = new WP_Error( 'theme_no_parent', sprintf( __( 'The parent theme is missing. Please install the "%s" parent theme.' ), $this->template ) );
 				$this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) );
+				$this->parent = new WP_Theme( $this->template, $this->theme_root, $this );
 				return;
 			}
 		}
@@ -1102,7 +1104,7 @@
 	public static function get_allowed_on_site( $blog_id = null ) {
 		static $allowed_themes = array();
 
-		if ( ! $blog_id )
+		if ( ! $blog_id || ! is_multisite() )
 			$blog_id = get_current_blog_id();
 
 		if ( isset( $allowed_themes[ $blog_id ] ) )
@@ -1110,18 +1112,24 @@
 
 		$current = $blog_id == get_current_blog_id();
 
-		if ( $current )
+		if ( $current ) {
 			$allowed_themes[ $blog_id ] = get_option( 'allowedthemes' );
-		else
-			$allowed_themes[ $blog_id ] = get_blog_option( $blog_id, 'allowedthemes' );
+		} else {
+			switch_to_blog( $blog_id );
+			$allowed_themes[ $blog_id ] = get_option( 'allowedthemes' );
+			restore_current_blog();
+		}
 
 		// This is all super old MU back compat joy.
 		// 'allowedthemes' keys things by stylesheet. 'allowed_themes' keyed things by name.
 		if ( false === $allowed_themes[ $blog_id ] ) {
-			if ( $current )
+			if ( $current ) {
 				$allowed_themes[ $blog_id ] = get_option( 'allowed_themes' );
-			else
-				$allowed_themes[ $blog_id ] = get_blog_option( $blog_id, 'allowed_themes' );
+			} else {
+				switch_to_blog( $blog_id );
+				$allowed_themes[ $blog_id ] = get_option( 'allowed_themes' );
+				restore_current_blog();
+			}
 
 			if ( ! is_array( $allowed_themes[ $blog_id ] ) || empty( $allowed_themes[ $blog_id ] ) ) {
 				$allowed_themes[ $blog_id ] = array();
@@ -1140,8 +1148,10 @@
 					update_option( 'allowedthemes', $allowed_themes[ $blog_id ] );
 					delete_option( 'allowed_themes' );
 				} else {
-					update_blog_option( $blog_id, 'allowedthemes', $allowed_themes[ $blog_id ] );
-					delete_blog_option( $blog_id, 'allowed_themes' );
+					switch_to_blog( $blog_id );
+					update_option( 'allowedthemes', $allowed_themes[ $blog_id ] );
+					delete_option( 'allowed_themes' );
+					restore_current_blog();
 				}
 			}
 		}