Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 7569)
+++ wp-includes/post.php	(working copy)
@@ -2408,7 +2408,7 @@
 			$dirs = apply_filters( 'icon_dirs', array($icon_dir => $icon_dir_uri) );
 			$icon_files = array();
 			while ( $dirs ) {
-				$dir = array_shift(array_keys($dirs));
+				$dir = array_shift($keys = array_keys($dirs));
 				$uri = array_shift($dirs);
 				if ( $dh = opendir($dir) ) {
 					while ( false !== $file = readdir($dh) ) {