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| author | Paul Ganssle <paul@ganssle.io> | 2018-08-14 10:09:08 -0400 |
|---|---|---|
| committer | Paul Ganssle <paul@ganssle.io> | 2018-08-14 10:58:16 -0400 |
| commit | 2e6138c75d01aade30554d6095d5aa112e8aa532 (patch) | |
| tree | b5d28519fa173ed7c904fa965f83e6fc5e8e412c /dateutil | |
| parent | 886ec3ee317aa1a15f1accd8bc6031e541ad36e1 (diff) | |
| download | dateutil-2e6138c75d01aade30554d6095d5aa112e8aa532.tar.gz | |
Stop trying to store None in weakref cache
None is a singleton and a weak reference to it will never expire, and in
this case it is used more as a soft failure mode than as an actual value
to return. By special-casing this, the invariant that:
gettz(x) is gettz(x)
is preserved in all cases *except* when something on the underlying
system changes such that `x` does not refer to a valid time zone in the
first call, but does refer to a valid time zone in the second call. This
could happen if `x` is added to the zoneinfo data, or if the local time
zone changes such that `x` is now a valid specifier for the local time.
Diffstat (limited to 'dateutil')
| -rw-r--r-- | dateutil/test/test_tz.py | 1 | ||||
| -rw-r--r-- | dateutil/tz/tz.py | 7 |
2 files changed, 6 insertions, 2 deletions
diff --git a/dateutil/test/test_tz.py b/dateutil/test/test_tz.py index 3140269..a65d387 100644 --- a/dateutil/test/test_tz.py +++ b/dateutil/test/test_tz.py @@ -1076,7 +1076,6 @@ class GettzTest(unittest.TestCase, TzFoldMixin): @pytest.mark.gettz -@pytest.mark.xfail def test_gettz_badzone(): # Make sure passing a bad TZ string to gettz returns None # GH #800 diff --git a/dateutil/tz/tz.py b/dateutil/tz/tz.py index ba0d8b7..3caac67 100644 --- a/dateutil/tz/tz.py +++ b/dateutil/tz/tz.py @@ -1539,10 +1539,15 @@ def __get_gettz(): if rv is None: rv = self.nocache(name=name) - if not (name is None or isinstance(rv, tzlocal_classes)): + if not (name is None + or isinstance(rv, tzlocal_classes) + or rv is None): # tzlocal is slightly more complicated than the other # time zone providers because it depends on environment # at construction time, so don't cache that. + # + # We also cannot store weak references to None, so we + # will also not store that. self.__instances[name] = rv return rv |