From 913e40e44ca301c0449299419b3ffda2a94ad520 Mon Sep 17 00:00:00 2001
From: Bogdan Gusiev <agresso@gmail.com>
Date: Sat, 31 Aug 2013 18:26:49 +0300
Subject: [PATCH] Fix I18n.interpolate when ActiveSupport::SafeBuffer passed as
 argument

---
 lib/i18n/interpolate/ruby.rb  |  2 +-
 test/i18n/interpolate_test.rb | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/i18n/interpolate/ruby.rb b/lib/i18n/interpolate/ruby.rb
index 442677f2..d2fdda75 100644
--- a/lib/i18n/interpolate/ruby.rb
+++ b/lib/i18n/interpolate/ruby.rb
@@ -22,7 +22,7 @@ def interpolate_hash(string, values)
         if match == '%%'
           '%'
         else
-          key = ($1 || $2).to_sym
+          key = ($1 || $2 || match.tr("%{}", "")).to_sym
           value = if values.key?(key)
                     values[key]
                   else
diff --git a/test/i18n/interpolate_test.rb b/test/i18n/interpolate_test.rb
index 7041b322..59f26791 100644
--- a/test/i18n/interpolate_test.rb
+++ b/test/i18n/interpolate_test.rb
@@ -58,6 +58,17 @@ class I18nInterpolateTest < Test::Unit::TestCase
   def test_sprintf_mix_unformatted_and_formatted_named_placeholders
     assert_equal "foo 1.000000", I18n.interpolate("%{name} %<num>f", :name => "foo", :num => 1.0)
   end
+
+  class RailsSafeBuffer < String
+
+    def gsub(*args, &block)
+      to_str.gsub(*args, &block)
+    end
+
+  end
+  test "with String subclass that redefined gsub method" do
+    assert_equal "Hello mars world", I18n.interpolate(RailsSafeBuffer.new("Hello %{planet} world"), :planet => 'mars') 
+  end
 end
 
 class I18nMissingInterpolationCustomHandlerTest < Test::Unit::TestCase