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| author | Derrick Stolee <dstolee@microsoft.com> | 2017-10-08 18:29:37 (GMT) |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2017-10-09 23:57:24 (GMT) |
| commit | 19716b21a4255ecc7148b54ab2c78039c59f25bf (patch) | |
| tree | 5f1cecbffc543c64e7c4c4f371d204424e1ce1bb /builtin/unpack-objects.c | |
| parent | 217f2767cbcb562872437eed4dec62e00846d90c (diff) | |
| download | git-19716b21a4255ecc7148b54ab2c78039c59f25bf.zip git-19716b21a4255ecc7148b54ab2c78039c59f25bf.tar.gz git-19716b21a4255ecc7148b54ab2c78039c59f25bf.tar.bz2 | |
cleanup: fix possible overflow errors in binary search
A common mistake when writing binary search is to allow possible
integer overflow by using the simple average:
mid = (min + max) / 2;
Instead, use the overflow-safe version:
mid = min + (max - min) / 2;
This translation is safe since the operation occurs inside a loop
conditioned on "min < max". The included changes were found using
the following git grep:
git grep '/ *2;' '*.c'
Making this cleanup will prevent future review friction when a new
binary search is contructed based on existing code.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'builtin/unpack-objects.c')
| -rw-r--r-- | builtin/unpack-objects.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c index 689a29f..62ea264 100644 --- a/builtin/unpack-objects.c +++ b/builtin/unpack-objects.c @@ -394,7 +394,7 @@ static void unpack_delta_entry(enum object_type type, unsigned long delta_size, lo = 0; hi = nr; while (lo < hi) { - mid = (lo + hi)/2; + mid = lo + (hi - lo) / 2; if (base_offset < obj_list[mid].offset) { hi = mid; } else if (base_offset > obj_list[mid].offset) { |