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The logic introduced in that commit performs a clamping to the bits, though, which fails to do what is needed here: If too many bytes are available in the buffers, we need to clamp to the maximum value of an `unsigned long`. Otherwise, we ask zlib to use too small buffers, in the worst case using 0 as the size (think: a value whose 32 lowest bits are all zero). Signed-off-by: Johannes Schindelin --- zlib: properly clamp to uLong I re-read this logic earlier this week... and I am quite convinced that it needs to be fixed. Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2153%2Fdscho%2Ffix-ulong-clamping-for-zlib-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2153/dscho/fix-ulong-clamping-for-zlib-v1 Pull-Request: https://github.com/gitgitgadget/git/pull/2153 git-zlib.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/git-zlib.c b/git-zlib.c index b91cb323ae..d21adb3bf5 100644 --- a/git-zlib.c +++ b/git-zlib.c @@ -38,12 +38,17 @@ static inline uInt zlib_buf_cap(unsigned long len) return (ZLIB_BUF_MAX < len) ? ZLIB_BUF_MAX : len; } +static inline uLong zlib_uLong_cap(size_t s) +{ + return s < ULONG_MAX_VALUE ? (uLong)s : ULONG_MAX_VALUE; +} + static void zlib_pre_call(git_zstream *s) { s->z.next_in = s->next_in; s->z.next_out = s->next_out; - s->z.total_in = (uLong)(s->total_in & ULONG_MAX_VALUE); - s->z.total_out = (uLong)(s->total_out & ULONG_MAX_VALUE); + s->z.total_in = zlib_uLong_cap(s->total_in); + s->z.total_out = zlib_uLong_cap(s->total_out); s->z.avail_in = zlib_buf_cap(s->avail_in); s->z.avail_out = zlib_buf_cap(s->avail_out); } @@ -60,7 +65,7 @@ static void zlib_post_call(git_zstream *s, int status) * We track our own totals and verify only the low bits match. */ if ((s->z.total_out & ULONG_MAX_VALUE) != - ((s->total_out + bytes_produced) & ULONG_MAX_VALUE)) + ((zlib_uLong_cap(s->total_out) + bytes_produced) & ULONG_MAX_VALUE)) BUG("total_out mismatch"); /* * zlib does not update total_in when it returns Z_NEED_DICT, @@ -68,7 +73,7 @@ static void zlib_post_call(git_zstream *s, int status) */ if (status != Z_NEED_DICT && (s->z.total_in & ULONG_MAX_VALUE) != - ((s->total_in + bytes_consumed) & ULONG_MAX_VALUE)) + ((zlib_uLong_cap(s->total_in) + bytes_consumed) & ULONG_MAX_VALUE)) BUG("total_in mismatch"); s->total_out += bytes_produced; base-commit: 7a094d68a27e321a99c8ab6b700909e503904bd9 -- gitgitgadget