[FFmpeg-devel] [PATCH 1/2] avcodec/avpacket: Use av_copy_packet_side_data() in av_packet_copy_props()

[Michael Niedermayer]

On Wed, May 03, 2017 at 12:54:53PM +0200, Hendrik Leppkes wrote:
> On Wed, May 3, 2017 at 11:50 AM, Michael Niedermayer
> <michael at niedermayer.cc> wrote:
> > On Wed, May 03, 2017 at 11:37:35AM +0200, wm4 wrote:
> >> On Wed, 3 May 2017 11:29:04 +0200
> >> Michael Niedermayer <michael at niedermayer.cc> wrote:
> >>
> >> > On Wed, May 03, 2017 at 05:29:07AM +0200, wm4 wrote:
> >> > > On Wed,  3 May 2017 05:21:50 +0200
> >> > > Michael Niedermayer <michael at niedermayer.cc> wrote:
> >> > >
> >> > > > Fixes timeout
> >> > > > Fixes: 1293/clusterfuzz-testcase-minimized-6054752074858496
> >> > > >
> >> > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
> >> > > > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> >> > > > ---
> >> > > >  libavcodec/avpacket.c | 3 +++
> >> > > >  1 file changed, 3 insertions(+)
> >> > > >
> >> > > > diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
> >> > > > index 4bf830bb8a..ff7ee730a4 100644
> >> > > > --- a/libavcodec/avpacket.c
> >> > > > +++ b/libavcodec/avpacket.c
> >> > > > @@ -557,6 +557,9 @@ FF_ENABLE_DEPRECATION_WARNINGS
> >> > > >      dst->flags                = src->flags;
> >> > > >      dst->stream_index         = src->stream_index;
> >> > > >
> >> > > > +    if (!dst->side_data_elems);
> >> > > > +        return av_copy_packet_side_data(dst, src);
> >> > > > +
> >> > > >      for (i = 0; i < src->side_data_elems; i++) {
> >> > > >           enum AVPacketSideDataType type = src->side_data[i].type;
> >> > > >           int size          = src->side_data[i].size;
> >> > >
> >> > > This doesn't look right...
> >> >
> >> > already fixed the ; locally
> >> >
> >> >
> >> > [...]
> >>
> >> I didn't see that, I was referring to the fact that you call
> >> av_copy_packet_side_data(), and only sometimes (at least by intention).
> >> That requires at least an explanation in the commit message.
> >
> > av_packet_copy_props() would add side data to the destination packet
> > it doesnt replace previously existing side data except in case of
> > error.
> > I dont know if that is intended but i didnt want to change it as that
> > would be unrelated to this patch
> >
> 
> This behavior seems odd at best, so maybe we should just change that
> and make the behavior more logical, and fix your issue at the same
> time?

That can be done and makes alot of sense after the patch.

we need to fix this issue in our releases too
a simple bugfix and a seperate behavior change afterwards allows us
to simply backport the bugfix from master.

That is unless theres consensus that the bevavior is a bug and should
be changed in affected releases?

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Frequently ignored answer#1 FFmpeg bugs should be sent to our bugtracker. User
questions about the command line tools should be sent to the ffmpeg-user ML.
And questions about how to use libav* should be sent to the libav-user ML.
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