From dfd88083f85115c62da5f2cca2e0e4a8430e2b76 Mon Sep 17 00:00:00 2001
From: Leigh Caplan <lcaplan@onehub.com>
Date: Mon, 28 Jun 2010 15:38:16 -0700
Subject: [PATCH] Rewrite the clause to pluck the existing value from zones_map before performing a lookup.

---
 .../lib/active_support/values/time_zone.rb         |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/activesupport/lib/active_support/values/time_zone.rb b/activesupport/lib/active_support/values/time_zone.rb
index 0c39c76..ad9ea2a 100644
--- a/activesupport/lib/active_support/values/time_zone.rb
+++ b/activesupport/lib/active_support/values/time_zone.rb
@@ -387,8 +387,10 @@ module ActiveSupport
       def [](arg)
         case arg
           when String
-            if tz = lookup(arg)
-              zones_map[arg] ||= tz
+            if tz = zones_map[arg]
+              tz
+            elsif tz = lookup(arg)
+              zones_map[arg] = tz
             end
           when Numeric, ActiveSupport::Duration
             arg *= 3600 if arg.abs <= 13
-- 
1.6.5.3