[FFmpeg-cvslog] avutil/log: fix race between setting and using the log callback

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Thu Oct 17 00:48:43 2013 +0200| [3ed65d98c616d52e2544c8b81aa3997f28bb88f5] | committer: Michael Niedermayer

avutil/log: fix race between setting and using the log callback

Found-by: wm4
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3ed65d98c616d52e2544c8b81aa3997f28bb88f5
---

 libavutil/log.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libavutil/log.c b/libavutil/log.c
index 53be3ea..5ee0c5d 100644
--- a/libavutil/log.c
+++ b/libavutil/log.c
@@ -268,8 +268,9 @@ void av_log(void* avcl, int level, const char *fmt, ...)
 
 void av_vlog(void* avcl, int level, const char *fmt, va_list vl)
 {
-    if(av_log_callback)
-        av_log_callback(avcl, level, fmt, vl);
+    void (*log_callback)(void*, int, const char*, va_list) = av_log_callback;
+    if (log_callback)
+        log_callback(avcl, level, fmt, vl);
 }
 
 int av_log_get_level(void)