Take DST into account when locating TimeZone from Numeric.

When given a specific offset, use the first result found where the
total current offset (including any periodic deviations such as DST)
from UTC is equal.

1 files changed, 7 insertions, 0 deletions

diff --git a/activesupport/test/core_ext/time_with_zone_test.rb b/activesupport/test/core_ext/time_with_zone_test.rb
index 92c233d567..0f5522b712 100644
--- a/activesupport/test/core_ext/time_with_zone_test.rb
+++ b/activesupport/test/core_ext/time_with_zone_test.rb
@@ -867,6 +867,13 @@ class TimeWithZoneMethodsForTimeAndDateTimeTest < ActiveSupport::TestCase
     end
   end
 
+  def test_in_time_zone_with_dst
+    travel_to(Time.utc(2014, 5, 20, 4, 59, 59))
+    time = Time.now.in_time_zone(-4)
+    assert_equal (-4*3600), time.time_zone.utc_total_offset
+    travel_back
+  end
+
   def test_in_time_zone_with_invalid_argument
     assert_raise(ArgumentError) {  @t.in_time_zone("No such timezone exists") }
     assert_raise(ArgumentError) { @dt.in_time_zone("No such timezone exists") }