From 0be1f1b24c960fda99ff1683c43c97ee26d735dd Mon Sep 17 00:00:00 2001 From: "T. Wouters" Date: Sun, 12 Nov 2023 00:56:27 +0100 Subject: [PATCH] Fix undefined behaviour in datetime.time.fromisoformat() (GH-111982) Fix undefined behaviour in datetime.time.fromisoformat() when parsing a string without a timezone. 'tzoffset' is not assigned to by parse_isoformat_time if it returns 0, but time_fromisoformat then passes tzoffset to another function, which is undefined behaviour (even if the function in question does not use the value). (cherry picked from commit 21615f77b5a580e83589abae618dbe7c298700e2) Co-authored-by: T. Wouters --- Modules/_datetimemodule.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c index d8183c63f449762..c8dbc750b0ef5bb 100644 --- a/Modules/_datetimemodule.c +++ b/Modules/_datetimemodule.c @@ -4620,7 +4620,7 @@ time_fromisoformat(PyObject *cls, PyObject *tstr) { } int hour = 0, minute = 0, second = 0, microsecond = 0; - int tzoffset, tzimicrosecond = 0; + int tzoffset = 0, tzimicrosecond = 0; int rv = parse_isoformat_time(p, len, &hour, &minute, &second, µsecond, &tzoffset, &tzimicrosecond);