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| author | Ammar Askar <ammar_askar@hotmail.com> | 2018-07-25 09:54:58 -0700 |
|---|---|---|
| committer | Alexander Belopolsky <abalkin@users.noreply.github.com> | 2018-07-25 12:54:58 -0400 |
| commit | 96d1e69a12ed8ab80203277e1abdaf573457a964 (patch) | |
| tree | e6cdbe9b8eec222ba25cf313c0ba4361f2dd68d9 /Modules/_datetimemodule.c | |
| parent | 74102c9a5f2327c4fc47feefa072854a53551d1f (diff) | |
| download | cpython-git-96d1e69a12ed8ab80203277e1abdaf573457a964.tar.gz | |
bpo-29097: Forego fold detection on windows for low timestamp values (GH-2385)
On Windows, passing a negative value to local results in an OSError because localtime_s on Windows does not support negative timestamps. Unfortunately this means that fold detection for timestamps between 0 and max_fold_seconds will result in this OSError since we subtract max_fold_seconds from the timestamp to detect a fold. However, since we know there haven't been any folds in the interval [0, max_fold_seconds) in any timezone, we can hackily just forego fold detection for this time range on Windows.
Diffstat (limited to 'Modules/_datetimemodule.c')
| -rw-r--r-- | Modules/_datetimemodule.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c index 31aa88d4a2..076912d58f 100644 --- a/Modules/_datetimemodule.c +++ b/Modules/_datetimemodule.c @@ -4625,7 +4625,22 @@ datetime_from_timet_and_us(PyObject *cls, TM_FUNC f, time_t timet, int us, second = Py_MIN(59, tm.tm_sec); /* local timezone requires to compute fold */ - if (tzinfo == Py_None && f == _PyTime_localtime) { + if (tzinfo == Py_None && f == _PyTime_localtime + /* On Windows, passing a negative value to local results + * in an OSError because localtime_s on Windows does + * not support negative timestamps. Unfortunately this + * means that fold detection for time values between + * 0 and max_fold_seconds will result in an identical + * error since we subtract max_fold_seconds to detect a + * fold. However, since we know there haven't been any + * folds in the interval [0, max_fold_seconds) in any + * timezone, we can hackily just forego fold detection + * for this time range. + */ +#ifdef MS_WINDOWS + && (timet - max_fold_seconds > 0) +#endif + ) { long long probe_seconds, result_seconds, transition; result_seconds = utc_to_seconds(year, month, day, |