https://github.com/python/cpython/commit/95f94d04d8772f926b6a9bc1e38b67218a1dba7a commit: 95f94d04d8772f926b6a9bc1e38b67218a1dba7a branch: main author: Jelle Zijlstra <[email protected]> committer: JelleZijlstra <[email protected]> date: 2026-10-20T10:20:20-07:00 summary:
gh-159739: Reject the minimum dynamic formatting width (#159780) Co-authored-by: Jelle Zijlstra <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-20-38-17.gh-issue-159739.78e530.rst M Lib/test/test_format.py M Objects/bytesobject.c M Objects/unicode_format.c diff --git a/Lib/test/test_format.py b/Lib/test/test_format.py index a69a69537d568d..eff0e95c3af7f4 100644 --- a/Lib/test/test_format.py +++ b/Lib/test/test_format.py @@ -324,6 +324,8 @@ def test_common_format(self): "format argument 1: too big for width") test_exc_common('%*r', (-2**1000, 1), OverflowError, "format argument 1: too big for width") + test_exc_common('%*r', (-maxsize - 1, 1), OverflowError, + "format argument 1: too big for width") test_exc_common('%.*r', (2**1000, 1), OverflowError, "format argument 1: too big for precision") test_exc_common('%.*r', (-2**1000, 1), OverflowError, diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-20-38-17.gh-issue-159739.78e530.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-20-38-17.gh-issue-159739.78e530.rst new file mode 100644 index 00000000000000..999efdac87f974 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-20-38-17.gh-issue-159739.78e530.rst @@ -0,0 +1,2 @@ +Raise :exc:`OverflowError` when the absolute value of a dynamic printf-style +formatting width is too large. diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c index a5c369757d452f..e9264f765a08e6 100644 --- a/Objects/bytesobject.c +++ b/Objects/bytesobject.c @@ -852,6 +852,10 @@ _PyBytes_FormatEx(const char *format, Py_ssize_t format_len, goto error; } if (width < 0) { + if (width == PY_SSIZE_T_MIN) { + FORMAT_ERROR(PyExc_OverflowError, "too big for width%s", ""); + goto error; + } flags |= F_LJUST; width = -width; } diff --git a/Objects/unicode_format.c b/Objects/unicode_format.c index caadf18f6a5d30..b090a68d2bda9f 100644 --- a/Objects/unicode_format.c +++ b/Objects/unicode_format.c @@ -564,6 +564,10 @@ unicode_format_arg_parse(struct unicode_formatter_t *ctx, return -1; } if (arg->width < 0) { + if (arg->width == PY_SSIZE_T_MIN) { + FORMAT_ERROR(PyExc_OverflowError, "too big for width%s", ""); + return -1; + } arg->flags |= F_LJUST; arg->width = -arg->width; } _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
