avformat/subviewerdec: Fix memleak upon read header failure

The already parsed subtitles (contained in an FFDemuxSubtitlesQueue)
would leak if an error happened upon reading a subsequent subtitle.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
(cherry picked from commit a708f652737eba08607df84394ca4bec6b458736)

1 files changed, 2 insertions, 0 deletions

diff --git a/libavformat/subviewerdec.c b/libavformat/subviewerdec.c
index 83378eab5f..fdca3a4820 100644
--- a/libavformat/subviewerdec.c
+++ b/libavformat/subviewerdec.c
@@ -172,6 +172,8 @@ static int subviewer_read_header(AVFormatContext *s)
     ff_subtitles_queue_finalize(s, &subviewer->q);
 
 end:
+    if (res < 0)
+        ff_subtitles_queue_clean(&subviewer->q);
     av_bprint_finalize(&header, NULL);
     return res;
 }