avcodec/sgidec: Support negative linesizes

The earlier code used "p->data[0] + p->linesize[0] * s->height" with
the latter being unsigned, which gives the wrong value for negative
linesizes. There is also a not so obvious problem with this:
In case of negative linesizes, the last line is the start of
the allocated buffer, so using the line after the last line
would involve undefined pointer arithmetic. So don't do it.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

0 files changed, 0 insertions, 0 deletions