lzo: fix overflow checking in copy_backptr()
authorXi Wang <xi.wang@gmail.com>
Fri, 15 Mar 2013 10:59:22 +0000 (06:59 -0400)
committerLuca Barbato <lu_zero@gentoo.org>
Fri, 15 Mar 2013 12:35:59 +0000 (13:35 +0100)
commitcab96248927a171821dcee1434d73489d1ef9723
treeb2d32bc0dfbd699f2a0f2fb7ef62d87623138cc9
parentd8010bda7a233fbfa05c3d7690d717a86102926c
lzo: fix overflow checking in copy_backptr()

The check `src > dst' in the form `&c->out[-back] > c->out' invokes
pointer overflow, which is undefined behavior in C.

Remove the check.  Also replace `&c->out[-back] < c->out_start' with
a safe form `c->out - c->out_start < back' to avoid overflow.

CC: libav-stable@libav.org
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
(cherry picked from commit ca6c3f2c53be70aa3c38e8f1292809db89ea1ba6)

Conflicts:
libavutil/lzo.c
libavutil/lzo.c