@leroysheep / LeeRoySheep / commits / 21f64467a7

git-zlib: widen `git_deflate_bound()` to `size_t`

All four `unsigned long`/`int`/`ssize_t` receivers across archive-zip, diff, http-push and t/helper/test-pack-deltas were widened to `size_t` in the prior commits, and remote-curl and fast-import were already there. With every caller prepared, both the parameter and the return type can now move without introducing any silent narrowing. For inputs above zlib's `uLong` range (i.e. >4 GiB on platforms where `uLong` is 32-bit, notably 64-bit Windows), defer to zlib's stored-block formula (the same fallback it would itself use for an unknown stream state) plus the worst-case wrapper overhead. The existing path through `deflateBound()` is unchanged for inputs that fit. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Jul 9, 2026 at 16:49 UTC 21f64467a7132cf25b965b9ee58afd7c0ffc31ea
2 files changed +15 -3
git-zlib.c
+14 -2
index d21adb3bf5..ebbbcc6d1a 100644 --- a/git-zlib.c +++ b/git-zlib.c @@ -167,9 +167,21 @@ int git_inflate(git_zstream *strm, int flush) return status; } -unsigned long git_deflate_bound(git_zstream *strm, unsigned long size) +size_t git_deflate_bound(git_zstream *strm, size_t size) { - return deflateBound(&strm->z, size); +#if SIZE_MAX > ULONG_MAX + if (size > maximum_unsigned_value_of_type(uLong)) + /* + * deflateBound() takes uLong, which is 32-bit on + * Windows. For inputs above that range, return zlib's + * stored-block formula (the conservative path it would + * itself use for an unknown stream state) plus the + * worst-case wrapper overhead. + */ + return size + (size >> 5) + (size >> 7) + (size >> 11) + + 7 + 18; +#endif + return deflateBound(&strm->z, (uLong)size); } void git_deflate_init(git_zstream *strm, int level)
git-zlib.h
+1 -1
index 0b24b15bd0..9248d11ca9 100644 --- a/git-zlib.h +++ b/git-zlib.h @@ -25,6 +25,6 @@ void git_deflate_end(git_zstream *); int git_deflate_abort(git_zstream *); int git_deflate_end_gently(git_zstream *); int git_deflate(git_zstream *, int flush); -unsigned long git_deflate_bound(git_zstream *, unsigned long); +size_t git_deflate_bound(git_zstream *, size_t); #endif /* GIT_ZLIB_H */