avformat/dashdec: fix pointer being freed was not allocated

prevent attempt to call xmlFree if val was not allocated
fixes: 8135

Reviewed-by: Steven Liu <lq@onvideo.cn>
Signed-off-by: vectronic <hello.vectronic@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
index 8c0a9b0102..738bfeaefb 100644
--- a/libavformat/dashdec.c
+++ b/libavformat/dashdec.c
@@ -1203,6 +1203,7 @@ static int parse_programinformation(AVFormatContext *s, xmlNodePtr node)
         }
         node = xmlNextElementSibling(node);
         xmlFree(val);
+        val = NULL;
     }
     return 0;
 }