avformat/mxfdec: treat Random Index Pack as end of file

RIP, if exists is the last KLV item in the MXF files therefore we can stop
parsing the file if it is encountered. This allows us to support files created by
broken muxers such as OpenCube MXFTk Advanced 2.8.0.0.1. which dumps some extra
garbage after the RIP.
Signed-off-by: Marton Balint <cus@passwd.hu>

libavformat/mxfdec.c

@@ -3739,7 +3739,10 @@ static int mxf_read_header(AVFormatContext *s)
     while (!avio_feof(s->pb)) {
         const MXFMetadataReadTableEntry *metadata;
 
-        if (klv_read_packet(&klv, s->pb) < 0) {
+        ret = klv_read_packet(&klv, s->pb);
+        if (ret < 0 || IS_KLV_KEY(klv.key, ff_mxf_random_index_pack_key)) {
+            if (ret >= 0 && avio_size(s->pb) > klv.next_klv)
+                av_log(s, AV_LOG_WARNING, "data after the RandomIndexPack, assuming end of file\n");
             /* EOF - seek to previous partition or stop */
             if(mxf_parse_handle_partition_or_eof(mxf) <= 0)
                 break;