[FFmpeg-cvslog] nutdec: only copy the header if it exists

[Andreas Cadhalpun]

ffmpeg | branch: release/2.4 | Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com> | Fri Dec 18 15:18:47 2015 +0100| [2306964b3a0336e24d1c9d04bd54aaecf2d198d7] | committer: Andreas Cadhalpun

nutdec: only copy the header if it exists

Fixes ubsan runtime error: null pointer passed as argument 2, which is
declared to never be null

Reviewed-by: Michael Niedermayer <michael at niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
(cherry picked from commit 9f82506c79874edd7b09707ab63d9e72078de8f9)
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2306964b3a0336e24d1c9d04bd54aaecf2d198d7
---

 libavformat/nutdec.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/nutdec.c b/libavformat/nutdec.c
index 76fd8cc..eec6423 100644
--- a/libavformat/nutdec.c
+++ b/libavformat/nutdec.c
@@ -1082,7 +1082,8 @@ static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code)
     ret = av_new_packet(pkt, size + nut->header_len[header_idx]);
     if (ret < 0)
         return ret;
-    memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
+    if (nut->header[header_idx])
+        memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
     pkt->pos = avio_tell(bc); // FIXME
     if (stc->last_flags & FLAG_SM_DATA) {
         int sm_size;