From fe63ec5dec454b8ac1e867bb2824bd96e1120e0c Mon Sep 17 00:00:00 2001
From: nacin <nacin@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Fri, 20 Apr 2012 13:22:54 +0000
Subject: [PATCH] If a cached theme root is no longer registered, skip it.
 Assume the cache is out of date. see #20103.

git-svn-id: http://svn.automattic.com/wordpress/trunk@20551 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/theme.php | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/wp-includes/theme.php b/wp-includes/theme.php
index c01c9a07f..34c028e81 100644
--- a/wp-includes/theme.php
+++ b/wp-includes/theme.php
@@ -340,6 +340,9 @@ function search_theme_directories( $force = false ) {
 		$cached_roots = get_site_transient( 'theme_roots' );
 		if ( is_array( $cached_roots ) ) {
 			foreach ( $cached_roots as $theme_dir => $theme_root ) {
+				// A cached theme root is no longer around, so skip it.
+				if ( ! isset( $relative_theme_roots[ $theme_root ] ) )
+					continue;
 				$found_themes[ $theme_dir ] = array(
 					'theme_file' => $theme_dir . '/style.css',
 					'theme_root' => $relative_theme_roots[ $theme_root ], // Convert relative to absolute.