From 3d9a0bd84de4c1655fecd5ef3cff7bc220f3e7ca Mon Sep 17 00:00:00 2001
From: Michael Pye <mail@mdpye.co.uk>
Date: Wed, 4 Mar 2015 09:39:42 +0000
Subject: [PATCH] Deal gracefully with nil parameters in comparison

Regression introduced in a8f9c92
---
 lib/signature.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/signature.rb b/lib/signature.rb
index 57b5867..19d16da 100644
--- a/lib/signature.rb
+++ b/lib/signature.rb
@@ -223,6 +223,8 @@ def validate_signature!(token)
 
       # Constant time string comparison
       def identical?(a, b)
+        return true if a.nil? && b.nil?
+        return false if a.nil? || b.nil?
         return false unless a.bytesize == b.bytesize
         a.bytes.zip(b.bytes).reduce(0) { |memo, (a, b)| memo += a ^ b } == 0
       end