[FFmpeg-cvslog] lavf/fifo: fix undefined behaviour in deinit when destroying mutex

[Marton Balint]

ffmpeg | branch: master | Marton Balint <cus at passwd.hu> | Sat Nov 12 02:07:24 2016 +0100| [e20e9b9033b75fac32a4a3bc2cdd3fcc3cedb33a] | committer: Marton Balint

lavf/fifo: fix undefined behaviour in deinit when destroying mutex

Reviewed-by: Jan Sebechlebsky <sebechlebskyjan at gmail.com>
Signed-off-by: Marton Balint <cus at passwd.hu>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e20e9b9033b75fac32a4a3bc2cdd3fcc3cedb33a
---

 libavformat/fifo.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavformat/fifo.c b/libavformat/fifo.c
index 15435fe..8f525e5 100644
--- a/libavformat/fifo.c
+++ b/libavformat/fifo.c
@@ -73,6 +73,7 @@ typedef struct FifoContext {
     int restart_with_keyframe;
 
     pthread_mutex_t overflow_flag_lock;
+    int overflow_flag_lock_initialized;
     /* Value > 0 signals queue overflow */
     volatile uint8_t overflow_flag;
 
@@ -515,6 +516,7 @@ static int fifo_init(AVFormatContext *avf)
     ret = pthread_mutex_init(&fifo->overflow_flag_lock, NULL);
     if (ret < 0)
         return AVERROR(ret);
+    fifo->overflow_flag_lock_initialized = 1;
 
     return 0;
 }
@@ -601,7 +603,8 @@ static void fifo_deinit(AVFormatContext *avf)
     av_dict_free(&fifo->format_options);
     avformat_free_context(fifo->avf);
     av_thread_message_queue_free(&fifo->queue);
-    pthread_mutex_destroy(&fifo->overflow_flag_lock);
+    if (fifo->overflow_flag_lock_initialized)
+        pthread_mutex_destroy(&fifo->overflow_flag_lock);
 }
 
 #define OFFSET(x) offsetof(FifoContext, x)