From d9d93aa55126ba11071e4ec256bac09086c6d191 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?tonghuaroot=20=28=E7=AB=A5=E8=AF=9D=29?= Date: Wed, 1 Jul 2026 17:54:02 +0800 Subject: [PATCH] gh-152157: Reject empty fractions in `_datetime.{date}time.fromisoformat` (GH-152161) (cherry picked from commit 112c69a0514902af2d2f7d0503de6690ca59a10f) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Co-authored-by: tonghuaroot (童话) Co-authored-by: Stan Ulbrych --- Lib/test/datetimetester.py | 8 +++++++ ...-06-25-07-08-17.gh-issue-152157.dt5Ef0.rst | 3 +++ Modules/_datetimemodule.c | 21 ++++++++++++------- 3 files changed, 24 insertions(+), 8 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2026-06-25-07-08-17.gh-issue-152157.dt5Ef0.rst diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py index 192b22ff754003..c11e9c068bed3b 100644 --- a/Lib/test/datetimetester.py +++ b/Lib/test/datetimetester.py @@ -3758,6 +3758,10 @@ def test_fromisoformat_fails_datetime(self): '2009-04-19T12:30:45-00:90:00', # Time zone field out from range '2009-04-19T12:30:45-00:00:90', # Time zone field out from range '2020-2020', # Ambiguous 9-char date portion + '2009-04-19T12:30:45.+05:00', # Empty fraction before offset + '2009-04-19T12:30:45.-05:00', # Empty fraction before offset + '2009-04-19T12:30:45.Z', # Empty fraction before Z + '2009-04-19T12:30:45,+05:00', # Empty fraction (comma) before offset ] for bad_str in bad_strs: @@ -5034,6 +5038,10 @@ def test_fromisoformat_fails(self): '24:01:00.000000', # Has non-zero minutes on 24:00 '12:30:45+00:90:00', # Time zone field out from range '12:30:45+00:00:90', # Time zone field out from range + '12:30:45.+05:00', # Empty fraction before offset + '12:30:45.-05:00', # Empty fraction before offset + '12:30:45.Z', # Empty fraction before Z + '12:30:45,+05:00', # Empty fraction (comma) before offset ] for bad_str in bad_strs: diff --git a/Misc/NEWS.d/next/Library/2026-06-25-07-08-17.gh-issue-152157.dt5Ef0.rst b/Misc/NEWS.d/next/Library/2026-06-25-07-08-17.gh-issue-152157.dt5Ef0.rst new file mode 100644 index 00000000000000..00e83b4af6be7a --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-06-25-07-08-17.gh-issue-152157.dt5Ef0.rst @@ -0,0 +1,3 @@ +The C implementations of :meth:`~datetime.datetime.fromisoformat` and :meth:`~datetime.time.fromisoformat` +now reject a decimal separator that is not followed by any +fractional digit before a timezone designator. diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c index d52969bef0070f..d218c989891c1b 100644 --- a/Modules/_datetimemodule.c +++ b/Modules/_datetimemodule.c @@ -1034,7 +1034,16 @@ parse_hh_mm_ss_ff(const char *tstr, const char *tstr_end, int *hour, has_separator = (c == ':'); } - if (p >= p_end) { + if (c == '.' || c == ',') { + if (i < 2) { + return -3; // Decimal mark on hour or minute + } + if (p >= p_end) { + return -3; // Decimal mark not followed by any digit + } + break; + } + else if (p >= p_end) { return c != '\0'; } else if (has_separator && (c == ':')) { @@ -1043,14 +1052,10 @@ parse_hh_mm_ss_ff(const char *tstr, const char *tstr_end, int *hour, } continue; } - else if (c == '.' || c == ',') { - if (i < 2) { - return -3; // Decimal mark on hour or minute - } - break; - } else if (!has_separator) { + else if (!has_separator) { --p; - } else { + } + else { return -4; // Malformed time separator } }