From fba41a5b3ab66cae213940c118d9d242eff7fdc5 Mon Sep 17 00:00:00 2001
From: westi <westi@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Fri, 30 Mar 2012 15:13:12 +0000
Subject: [PATCH] Avoid fatal errors in check_theme_switched() if we fail to
 get a WP_Theme object for the old theme. Fixes #20334.

git-svn-id: http://svn.automattic.com/wordpress/trunk@20330 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/theme.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/wp-includes/theme.php b/wp-includes/theme.php
index 8bfdd74a5..14311b268 100644
--- a/wp-includes/theme.php
+++ b/wp-includes/theme.php
@@ -1555,7 +1555,13 @@ add_action( 'delete_attachment', '_delete_attachment_theme_mod' );
 function check_theme_switched() {
 	if ( $stylesheet = get_option( 'theme_switched' ) ) {
 		$old_theme = wp_get_theme( $stylesheet );
-		do_action( 'after_switch_theme', $old_theme->get('Name'), $old_theme );
+
+		// If we can't find the old theme then fallback to passing the raw data to the action like we did pre-3.4
+		if ( $old_theme )
+			do_action( 'after_switch_theme', $old_theme->get('Name'), $old_theme );
+		else
+			do_action( 'after_switch_theme', $stylesheet );
+
 		update_option( 'theme_switched', false );
 	}
 }