Closes issue #23600: Wrong results from tzinfo.fromutc().
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index a942d4d..3d50fc1 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -180,6 +180,29 @@
self.assertEqual(derived.utcoffset(None), offset)
self.assertEqual(derived.tzname(None), oname)
+ def test_issue23600(self):
+ DSTDIFF = DSTOFFSET = timedelta(hours=1)
+
+ class UKSummerTime(tzinfo):
+ """Simple time zone which pretends to always be in summer time, since
+ that's what shows the failure.
+ """
+
+ def utcoffset(self, dt):
+ return DSTOFFSET
+
+ def dst(self, dt):
+ return DSTDIFF
+
+ def tzname(self, dt):
+ return 'UKSummerTime'
+
+ tz = UKSummerTime()
+ u = datetime(2014, 4, 26, 12, 1, tzinfo=tz)
+ t = tz.fromutc(u)
+ self.assertEqual(t - t.utcoffset(), u)
+
+
class TestTimeZone(unittest.TestCase):
def setUp(self):