--- a/media/libnestegg/README_MOZILLA
+++ b/media/libnestegg/README_MOZILLA
@@ -1,8 +1,8 @@
 The source from this directory was copied from the nestegg
 git repository using the update.sh script.  The only changes
 made were those applied by update.sh and the addition of
 Makefile.in build files for the Mozilla build system.
 
 The nestegg git repository is: https://github.com/kinetiknz/nestegg
 
-The git commit ID used was 017f480db78bcdc607e6dba36cef806b793edf2c.
+The git commit ID used was 89ed0daf2edccb25f744e5faff88b8b4684adceb.

--- a/media/libnestegg/src/nestegg.c
+++ b/media/libnestegg/src/nestegg.c
@@ -1545,18 +1545,21 @@ ne_read_block(nestegg * ctx, uint64_t bl
   if (tc_scale == 0)
     return -1;
 
   if (!ctx->read_cluster_timecode)
     return -1;
   cluster_tc = ctx->cluster_timecode;
 
   abs_timecode = timecode + cluster_tc;
-  if (abs_timecode < 0)
-    return -1;
+  if (abs_timecode < 0) {
+      /* Ignore the spec and negative timestamps */
+      ctx->log(ctx, NESTEGG_LOG_WARNING, "ignoring negative timecode: %lld", abs_timecode);
+      abs_timecode = 0;
+  }
 
   pkt = ne_alloc(sizeof(*pkt));
   if (!pkt)
     return -1;
   pkt->track = track;
   pkt->timecode = abs_timecode * tc_scale * track_scale;
   pkt->keyframe = keyframe;
 
@@ -1681,16 +1684,17 @@ ne_read_block_additions(nestegg * ctx, u
   assert(*pkt_block_additional == NULL);
 
   block_additions_end = ne_io_tell(ctx->io) + block_size;
 
   while (ne_io_tell(ctx->io) < block_additions_end) {
     add_id = 1;
     data = NULL;
     has_data = 0;
+    data_size = 0;
     r = ne_read_element(ctx, &id, &size);
     if (r != 1)
       return r;
 
     if (id != ID_BLOCK_MORE) {
       /* We don't know what this element is, so skip over it */
       if (id != ID_VOID && id != ID_CRC32)
         ctx->log(ctx, NESTEGG_LOG_DEBUG,