From c185a83de7bb281f4fa6e2816763b3d14cb5fdc6 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Fri, 5 Jun 2026 12:21:20 +0200 Subject: [PATCH] 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 --- git-zlib.c | 16 ++++++++++++++-- git-zlib.h | 2 +- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/git-zlib.c b/git-zlib.c index b91cb323ae..3a91fe7670 100644 --- a/git-zlib.c +++ b/git-zlib.c @@ -162,9 +162,21 @@ 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) diff --git a/git-zlib.h b/git-zlib.h 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 */