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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2022-04-14 01:38:55 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-04-14 01:38:55 (GMT) |
| commit | edf1a77f239069235f59103cfd8ce7f939c7fd10 (patch) | |
| tree | af006d0db7fed16d8592df34ced5dc12ac282fdd /Objects | |
| parent | a8d245a675c11972390d1cfaea4a97151162e6e7 (diff) | |
| download | cpython-edf1a77f239069235f59103cfd8ce7f939c7fd10.zip cpython-edf1a77f239069235f59103cfd8ce7f939c7fd10.tar.gz cpython-edf1a77f239069235f59103cfd8ce7f939c7fd10.tar.bz2 | |
gh-91421: Use constant value check during runtime (GH-91422) (GH-91493)
The left-hand side expression of the if-check can be converted to a
constant by the compiler, but the addition on the right-hand side is
performed during runtime.
Move the addition from the right-hand side to the left-hand side by
turning it into a subtraction there. Since the values are known to
be large enough to not turn negative, this is a safe operation.
Prevents a very unlikely integer overflow on 32 bit systems.
Fixes GH-91421.
(cherry picked from commit 0859368335d470b9ff33fc53ed9a85ec2654b278)
Co-authored-by: Tobias Stoeckmann <stoeckmann@users.noreply.github.com>
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/unicodeobject.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index 7767d14..369f913 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -5219,7 +5219,7 @@ _Py_DecodeUTF8Ex(const char *s, Py_ssize_t size, wchar_t **wstr, size_t *wlen, /* Note: size will always be longer than the resulting Unicode character count */ - if (PY_SSIZE_T_MAX / (Py_ssize_t)sizeof(wchar_t) < (size + 1)) { + if (PY_SSIZE_T_MAX / (Py_ssize_t)sizeof(wchar_t) - 1 < size) { return -1; } |