Adding fix for #2001

git-svn-id: https://svn.cakephp.org/repo/branches/1.2.x.x@4384 3807eeeb-6ff5-0310-8944-8be069107fe0

cake/basics.php

@@ -1050,7 +1050,10 @@
 		}
 
 		$timediff = $expires - $now;
-		$filetime = @filemtime($filename);
+		$filetime = false;
+		if(file_exists($filename)) {
+			$filetime = @filemtime($filename);
+		}
 
 		if ($data === null) {
 			// Read data from file