From b14e2379fbf4135f767bb4acc52036a340d5d023 Mon Sep 17 00:00:00 2001
From: nacin <nacin@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Fri, 30 Mar 2012 13:10:52 +0000
Subject: [PATCH] Check for is_rtl() existence before checking it in the
 fallback condition in wp_admin_css(). Prevents fatal errors when plugins call
 wp_admin_css() on a non-existent (probably removed) stylesheet. props
 SergeyBiryukov, fixes #19913.

git-svn-id: http://svn.automattic.com/wordpress/trunk@20326 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/general-template.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/wp-includes/general-template.php b/wp-includes/general-template.php
index e86963e6ee..63e6d6524a 100644
--- a/wp-includes/general-template.php
+++ b/wp-includes/general-template.php
@@ -2100,7 +2100,7 @@ function wp_admin_css( $file = 'wp-admin', $force_echo = false ) {
 	}
 
 	echo apply_filters( 'wp_admin_css', "<link rel='stylesheet' href='" . esc_url( wp_admin_css_uri( $file ) ) . "' type='text/css' />\n", $file );
-	if ( is_rtl() )
+	if ( function_exists( 'is_rtl' ) && is_rtl() )
 		echo apply_filters( 'wp_admin_css', "<link rel='stylesheet' href='" . esc_url( wp_admin_css_uri( "$file-rtl" ) ) . "' type='text/css' />\n", "$file-rtl" );
 }