Index: wp-includes/deprecated.php
===================================================================
--- wp-includes/deprecated.php	(revision 20304)
+++ wp-includes/deprecated.php	(working copy)
@@ -3071,7 +3071,9 @@
  */
 function get_theme_data( $theme_file ) {
 	_deprecated_function( __FUNCTION__, 3.4, 'wp_get_theme()' );
-	$theme = new WP_Theme( basename( dirname( $theme_file ) ), dirname( dirname( $theme_file ) ) );
+	$theme_root = trailingslashit( get_theme_root( $theme_file ) );
+	$theme_slug = str_replace( $theme_root, '', dirname( $theme_file ) );
+	$theme = new WP_Theme( $theme_slug, $theme_root );
 
 	$theme_data = array(
 		'Name' => $theme->get('Name'),
@@ -3088,4 +3090,4 @@
 	);
 
 	return $theme_data;
-}
\ No newline at end of file
+}