Review of attachment 318384 [details] [review]:

::: gst/matroska/matroska-demux.c
@@ +4840,3 @@
+      gst_event_parse_tag (event, &new_list);
+      gst_matroska_read_common_found_global_tag (&demux->common,
+          GST_ELEMENT_CAST (demux), new_list);

After this gst_matroska_demux_send_tags() needs to be called at some point. Maybe should be called before every gst_pad_push()?

In your case it probably works without because your tags arrive before the header of the Matroska file is parsed, and during header parsing that function is called anyway.

Created attachment 318391 [details] [review]
[PATCH] Allow matroska demux to propagate incoming tags from sink

missing line added

Review of attachment 318391 [details] [review]:

::: gst/matroska/matroska-demux.c
@@ +4841,3 @@
+      gst_matroska_read_common_found_global_tag (&demux->common,
+          GST_ELEMENT_CAST (demux), new_list);
+      gst_matroska_demux_send_tags (demux);

I don't think that works as is... you don't necessarily have any source pads at this point. That's why I said it should probably happen before pushing buffers... but maybe *also* before pushing buffers and having it here.

register tags in sink function and send tags in chain function ?

Yes, any progress here?

Closing this bug report as no further information has been provided. Please feel free to reopen this bug report if you can provide the information that was asked for in a previous comment.
Thanks!