avformat/matroskadec: Check avpriv_new_chapter() for failure

Fixes null pointer dereference

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 87dc8b3af9135f0cfcdf3c0520e3f29e7b0d92c6)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 4 insertions, 2 deletions

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index ec43526727..fdfba57d92 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -2161,8 +2161,10 @@ static int matroska_read_header(AVFormatContext *s)
                                    (AVRational) { 1, 1000000000 },
                                    chapters[i].start, chapters[i].end,
                                    chapters[i].title);
-            av_dict_set(&chapters[i].chapter->metadata,
-                        "title", chapters[i].title, 0);
+            if (chapters[i].chapter) {
+                av_dict_set(&chapters[i].chapter->metadata,
+                            "title", chapters[i].title, 0);
+            }
             max_start = chapters[i].start;
         }