From 55fa22caa9fd17a94604c95634774a79da883cca Mon Sep 17 00:00:00 2001
From: Brian Gough <brian.gough@overleaf.com>
Date: Mon, 15 Oct 2018 10:01:52 +0100
Subject: [PATCH] fix exception when content undefined in TikzManager

---
 services/clsi/app/coffee/TikzManager.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/services/clsi/app/coffee/TikzManager.coffee b/services/clsi/app/coffee/TikzManager.coffee
index 5b80e6c7c4..22def278b1 100644
--- a/services/clsi/app/coffee/TikzManager.coffee
+++ b/services/clsi/app/coffee/TikzManager.coffee
@@ -22,7 +22,7 @@ module.exports = TikzManager =
 			SafeReader.readFile path, 65536, "utf8", (error, content) ->
 				return callback(error) if error?
 				usesTikzExternalize = content?.indexOf("\\tikzexternalize") >= 0
-				usesPsTool = content.indexOf("{pstool}") >= 0
+				usesPsTool = content?.indexOf("{pstool}") >= 0
 				logger.log compileDir: compileDir, mainFile: mainFile, usesTikzExternalize:usesTikzExternalize, usesPsTool: usesPsTool, "checked for packages needing main file as output.tex"
 				needsMainFile = (usesTikzExternalize || usesPsTool)
 				callback null, needsMainFile