[#5559] Do not black out the system timezone DST jump hour if Time.zone differs from that.

The system timezone DST jump hour should not be blacked out by Time.zone.parse if current Time.zone does not do the jump at that time.

Fixes #5559.

activesupport/lib/active_support/values/time_zone.rb

@@ -268,7 +268,12 @@ def parse(str, now=now)
       date_parts = Date._parse(str)
       return if date_parts.empty?
       time = Time.parse(str, now) rescue DateTime.parse(str)
+
       if date_parts[:offset].nil?
+        if date_parts[:hour] && time.hour != date_parts[:hour]
+          time = DateTime.parse(str)
+        end
+
         ActiveSupport::TimeWithZone.new(nil, self, time)
       else
         time.in_time_zone(self)

activesupport/test/time_zone_test.rb

@@ -203,6 +203,24 @@ def test_parse_with_incomplete_date
     assert_equal Time.utc(1999,12,31,19), twz.time
   end
 
+  def test_parse_should_not_black_out_system_timezone_dst_jump
+    zone = ActiveSupport::TimeZone['Pacific Time (US & Canada)']
+    zone.stubs(:now).returns(zone.now)
+    Time.stubs(:parse).with('2012-03-25 03:29', zone.now).
+                       returns(Time.local(0,29,4,25,3,2012,nil,nil,true,"+03:00"))
+    twz = zone.parse('2012-03-25 03:29')
+    assert_equal [0, 29, 3, 25, 3, 2012], twz.to_a[0,6]
+  end
+
+  def test_parse_should_black_out_app_timezone_dst_jump
+    zone = ActiveSupport::TimeZone['Pacific Time (US & Canada)']
+    zone.stubs(:now).returns(zone.now)
+    Time.stubs(:parse).with('2012-03-11 02:29', zone.now).
+                       returns(Time.local(0,29,2,11,3,2012,nil,nil,false,"+02:00"))
+    twz = zone.parse('2012-03-11 02:29')
+    assert_equal [0, 29, 3, 11, 3, 2012], twz.to_a[0,6]
+  end
+
   def test_utc_offset_lazy_loaded_from_tzinfo_when_not_passed_in_to_initialize
     tzinfo = TZInfo::Timezone.get('America/New_York')
     zone = ActiveSupport::TimeZone.create(tzinfo.name, nil, tzinfo)