From 23755473ac86ef5a115e4f2a569ab808dd8e8b6d Mon Sep 17 00:00:00 2001
From: Andrew Nacin <nacin@git.wordpress.org>
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 Assume the cache is out of date.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: https://develop.svn.wordpress.org/trunk@20551 602fd350-edb4-49c9-b593-d223f7449a82
---
 wp-includes/theme.php | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/wp-includes/theme.php b/wp-includes/theme.php
index c01c9a07fd..34c028e816 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.