QFreeList: fix undefined behavior

Signed integer overflow is undefined behavior ([expr]/4),
but unsigned arithmetic doesn't overflow, so isn't
([basic.fundamental]/4, footnote there).

So, use unsigned arithmetic for the loop-around serial
number generation in incrementserial(). While we're at
it, also use it for the masking operation in the same
function.

Found by UBSan.

Change-Id: I500fae9d80fd3f6e39d06e79a53d271b82ea8df8
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

0 files changed, 0 insertions, 0 deletions