Followup to issue #14157: respect the relative ordering of values produced by time.strptime().

pitrou · pitrou · commit e2eab5e768ca · 2012-05-14T19:45:27.000+02:00
Patch by Hynek.
diff --git a/Lib/_strptime.py b/Lib/_strptime.py
@@ -444,8 +444,10 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
                     else:
                         tz = value
                         break
+    leap_year_fix = False
     if year is None and month == 2 and day == 29:
         year = 1904  # 1904 is first leap year of 20th century
+        leap_year_fix = True
     elif year is None:
         year = 1900
     # If we know the week of the year and what day of that week, we can figure
@@ -476,6 +478,12 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
     else:
         gmtoff = None
 
+    if leap_year_fix:
+        # the caller didn't supply a year but asked for Feb 29th. We couldn't
+        # use the default of 1900 for computations. We set it back to ensure
+        # that February 29th is smaller than March 1st.
+        year = 1900
+
     return (year, month, day,
             hour, minute, second,
             weekday, julian, tz, gmtoff, tzname), fraction
diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py
@@ -381,6 +381,11 @@ def test_escaping(self):
     def test_feb29_on_leap_year_without_year(self):
         time.strptime("Feb 29", "%b %d")
 
+    def test_mar1_comes_after_feb29_even_when_omitting_the_year(self):
+        self.assertLess(
+                time.strptime("Feb 29", "%b %d"),
+                time.strptime("Mar 1", "%b %d"))
+
 class Strptime12AMPMTests(unittest.TestCase):
     """Test a _strptime regression in '%I %p' at 12 noon (12 PM)"""
 
