This is more correct and avoids breaking extended_data.

This is more correct and avoids breaking extended_data.

CC:libav-stable@libav.org

sws_getCachedContext() and sws_getContext() expect sws_alloc_context()
to return NULL when out of memory, as follows.

    if (!(context = sws_alloc_context()))
        return NULL;

This patch fixes sws_alloc_context() to return NULL in that case.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

The following out-of-memory check is broken.

    *sorted_segments  = av_mallocz(...);
    if (!sorted_segments) { ... }

The correct NULL check should use *sorted_segments.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>