avoid shifting signed integers 31 bits

We sometimes use 32-bit unsigned integers as bit-fields.
It's fine to access the MSB, because it's unsigned. However,
doing so as "1 << 31" is wrong, because the constant "1" is
a signed int, and we shift into the sign bit, causing
undefined behavior.

We can fix this by using "1U" as the constant.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King
2015-12-29 01:35:46 -05:00
committed by Junio C Hamano
parent 1ff88560c8
commit 9a93c6686f
3 changed files with 3 additions and 3 deletions

View File

@ -1597,7 +1597,7 @@ static void prepare_shallow_update(struct command *commands,
continue;
si->need_reachability_test[i]++;
for (k = 0; k < 32; k++)
if (si->used_shallow[i][j] & (1 << k))
if (si->used_shallow[i][j] & (1U << k))
si->shallow_ref[j * 32 + k]++;
}