1 files changed, 82 insertions, 1 deletions
diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py
index 460c989..4459f3e 100644
--- a/Lib/test/test_time.py
+++ b/Lib/test/test_time.py
@@ -48,11 +48,92 @@ class TimeTestCase(unittest.TestCase):
             except ValueError:
                 self.fail('conversion specifier: %r failed.' % format)
 
-
     def test_asctime(self):
         time.asctime(time.gmtime(self.t))
         self.assertRaises(TypeError, time.asctime, 0)
 
+    def test_tzset(self):
+        from os import environ
+
+        # Epoch time of midnight Dec 25th 2002. Never DST in northern 
+        # hemisphere.
+        xmas2002 = 1040774400.0 
+
+        org_TZ = environ.get('TZ',None)
+        try:
+
+            # Make sure we can switch to UTC time and results are correct
+            # Note that unknown timezones default to UTC.
+            for tz in ('UTC','GMT','Luna/Tycho'):
+                environ['TZ'] = 'US/Eastern'
+                time.tzset()
+                environ['TZ'] = tz
+                time.tzset()
+                self.failUnlessEqual(
+                    time.gmtime(xmas2002),time.localtime(xmas2002)
+                    )
+                self.failUnlessEqual(time.timezone,time.altzone)
+                self.failUnlessEqual(time.daylight,0) 
+                self.failUnlessEqual(time.timezone,0)
+                self.failUnlessEqual(time.altzone,0)
+                self.failUnlessEqual(time.localtime(xmas2002).tm_isdst,0)
+
+            # Make sure we can switch to US/Eastern
+            environ['TZ'] = 'US/Eastern'
+            time.tzset()
+            self.failIfEqual(time.gmtime(xmas2002),time.localtime(xmas2002))
+            self.failUnlessEqual(time.tzname,('EST','EDT'))
+            self.failUnlessEqual(len(time.tzname),2)
+            self.failUnlessEqual(time.daylight,1)
+            self.failUnlessEqual(time.timezone,18000)
+            self.failUnlessEqual(time.altzone,14400)
+            self.failUnlessEqual(time.localtime(xmas2002).tm_isdst,0)
+            self.failUnlessEqual(len(time.tzname),2)
+
+            # Now go to the southern hemisphere. We want somewhere all OS's
+            # know about that has DST.
+            environ['TZ'] = 'Australia/Melbourne'
+            time.tzset()
+            self.failIfEqual(time.gmtime(xmas2002),time.localtime(xmas2002))
+            self.failUnless(time.tzname[0] in ('EST','AEST'))
+            self.failUnless(time.tzname[1] in ('EST','EDT','AEDT'))
+            self.failUnlessEqual(len(time.tzname),2)
+            self.failUnlessEqual(time.daylight,1)
+            self.failUnlessEqual(time.timezone,-36000)
+            self.failUnlessEqual(time.altzone,-39600)
+            self.failUnlessEqual(time.localtime(xmas2002).tm_isdst,1)
+
+            # Get some times from a timezone that isn't wallclock timezone
+            del environ['TZ']
+            time.tzset()
+            if time.timezone == 0:
+                environ['TZ'] = 'US/Eastern'
+            else:
+                environ['TZ'] = 'UTC'
+            time.tzset()
+            nonlocal = time.localtime(xmas2002)
+
+            # Then the same time in wallclock timezone
+            del environ['TZ']
+            time.tzset()
+            local = time.localtime(xmas2002)
+
+            # And make sure they arn't the same
+            self.failIfEqual(local,nonlocal) 
+
+            # Do some basic sanity checking after wallclock time set
+            self.failUnlessEqual(len(time.tzname),2)
+            time.daylight
+            time.timezone
+            time.altzone
+        finally:
+            # Repair TZ environment variable in case any other tests
+            # rely on it.
+            if org_TZ is not None:
+                environ['TZ'] = org_TZ
+            elif environ.has_key('TZ'):
+                del environ['TZ']
+            
 
 def test_main():
     test_support.run_unittest(TimeTestCase)