From 3ab1a87be328bd65ceeb7464f81f96343c72f102 Mon Sep 17 00:00:00 2001
From: Sam Saffron <sam.saffron@gmail.com>
Date: Thu, 12 May 2016 11:38:43 +1000
Subject: [PATCH] remove warning

---
 lib/mini_racer.rb | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/mini_racer.rb b/lib/mini_racer.rb
index da5d571..1970d72 100644
--- a/lib/mini_racer.rb
+++ b/lib/mini_racer.rb
@@ -15,6 +15,8 @@ module MiniRacer
       if js_backtrace && !js_backtrace.empty?
         @js_backtrace = js_backtrace.split("\n")
         @js_backtrace.map!{|f| "JavaScript #{f.strip}"}
+      else
+        @js_backtrace = nil
       end
 
       super(message)
@@ -32,7 +34,7 @@ module MiniRacer
 
   end
 
-  # helper class returned
+  # helper class returned when we have a JavaScript function
   class JavaScriptFunction
     def to_s
       "JavaScript Function"