[FFmpeg-cvslog] avformat/subtitles: Don't increment packet counter prematurely

[Andreas Rheinhardt]

ffmpeg | branch: release/4.2 | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Sat Mar 21 04:50:20 2020 +0100| [2765e927315c87cede25d42fbcf4f1f41bfed5a5] | committer: Andreas Rheinhardt

avformat/subtitles: Don't increment packet counter prematurely

Do it only if the packet has been successfully allocated in
av_new_packet() -- otherwise on error a completely uninitialized packet
would be unreferenced later.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 6bd8bcc2ac4c64577d964552317989e61db794d8)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2765e927315c87cede25d42fbcf4f1f41bfed5a5
---

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

diff --git a/libavformat/subtitles.c b/libavformat/subtitles.c
index a3240d88a1..849ccccbcb 100644
--- a/libavformat/subtitles.c
+++ b/libavformat/subtitles.c
@@ -132,9 +132,10 @@ AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
         if (!subs)
             return NULL;
         q->subs = subs;
-        sub = &subs[q->nb_subs++];
+        sub = &subs[q->nb_subs];
         if (av_new_packet(sub, len) < 0)
             return NULL;
+        q->nb_subs++;
         sub->flags |= AV_PKT_FLAG_KEY;
         sub->pts = sub->dts = 0;
         memcpy(sub->data, event, len);