Merge lp:~fgallaire/bzr/fix-localtime into lp:bzr

[Florent Gallaire]

Fix buggy on Windows and 32-bit platforms local_time_offset().
_format_date() fail back to 'original' timezone when 'local' is buggy.

[lp:~fgallaire/bzr/fix-localtime]

6623. By Florent Gallaire on 2017-03-22

Fix for Windows and 32-bit platforms buggy local_time_offset().

Unmerged revisions

6623. By Florent Gallaire on 2017-03-22

Fix for Windows and 32-bit platforms buggy local_time_offset().

=== modified file 'bzrlib/osutils.py'
--- bzrlib/osutils.py	2017-03-17 10:39:02 +0000
+++ bzrlib/osutils.py	2017-03-22 04:32:31 +0000
@@ -839,11 +839,18 @@
 
 
 def local_time_offset(t=None):
-    """Return offset of local zone from GMT, either at present or at time t."""
+    """Return offset of local zone from GMT, either at present or at time t.
+    Return None if buggy gmtime() or localtime().
+    """
     if t is None:
         t = time.time()
-    offset = datetime.fromtimestamp(t) - datetime.utcfromtimestamp(t)
-    return offset.days * 86400 + offset.seconds
+    try:
+        # datetime.fromtimestamp() and datetime.utcfromtimestamp() are as buggy
+        # as time.gmtime(). Not fixable (https://bugs.python.org/issue1647654).
+        offset = datetime.fromtimestamp(t) - datetime.utcfromtimestamp(t)
+        return offset.days * 86400 + offset.seconds
+    except ValueError:
+        return None
 
 weekdays = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
 _default_format_by_weekday_num = [wd + " %Y-%m-%d %H:%M:%S" for wd in weekdays]
@@ -922,8 +929,15 @@
             offset = 0
         tt = gmtime(t + offset)
     elif timezone == 'local':
-        tt = time.localtime(t)
-        offset = local_time_offset(t)
+        local_offset = local_time_offset(t)
+        if local_offset:
+            tt = time.localtime(t)
+            offset = local_offset
+        else:
+            # If buggy, use 'original' timezone
+            if offset is None:
+                offset = 0
+            tt = gmtime(t + offset)
     else:
         raise errors.UnsupportedTimezoneFormat(timezone)
     if date_fmt is None:

=== modified file 'bzrlib/tests/test_osutils.py'
--- bzrlib/tests/test_osutils.py	2016-02-01 18:06:32 +0000
+++ bzrlib/tests/test_osutils.py	2017-03-22 04:32:31 +0000
@@ -436,6 +436,18 @@
         eighteen_hours = 18 * 3600
         self.assertTrue(-eighteen_hours < offset < eighteen_hours)
 
+    def test_local_time_offset_with_negative_windows_timestamp(self):
+        # Fri 1969-10-10 00:00:00 +0000
+        offset = osutils.local_time_offset(-7171200)
+
+    def test_local_time_offset_with_negative_32bit_timestamp(self):
+        # Mon 1900-01-01 00:00:00 +0000
+        offset = osutils.local_time_offset(-2208988800)
+
+    def test_local_time_offset_with_positive_32bit_timestamp(self):
+        # Sat 2039-01-01 00:00:00 +0000
+        offset = osutils.local_time_offset(2177452800)
+
 
 class TestFdatasync(tests.TestCaseInTempDir):
 

=== modified file 'doc/en/release-notes/bzr-2.8.txt'
--- doc/en/release-notes/bzr-2.8.txt	2017-03-17 10:39:02 +0000
+++ doc/en/release-notes/bzr-2.8.txt	2017-03-22 04:32:31 +0000
@@ -39,6 +39,9 @@
  * Fix for Windows and 32-bit platforms buggy gmtime().
    (Florent Gallaire, #1669178, #1670243)
 
+ * Fix for Windows and 32-bit platforms buggy local_time_offset().
+   (Florent Gallaire, #1674195)
+
 Documentation
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