From 6cf27b550d66963b89b5917568b85c4b49fb18ba Mon Sep 17 00:00:00 2001
From: Vittorio Giovara <vittorio.giovara@gmail.com>
Date: Sat, 18 Oct 2014 01:12:13 +0100
Subject: [PATCH] aviobuf: check context before using it

Avoid a possible null pointer dereference.

CC: libav-stable@libav.org
Bug-Id: CID 1135769
---
 libavformat/aviobuf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index cc79146225..6923b78ea1 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -965,7 +965,7 @@ int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
 
 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
 {
-    DynBuffer *d = s->opaque;
+    DynBuffer *d;
     int size;
     static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
     int padding = 0;
@@ -983,6 +983,7 @@ int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
 
     avio_flush(s);
 
+    d = s->opaque;
     *pbuffer = d->buffer;
     size = d->size;
     av_free(d);