Weird messed up timeline when joining a room for the first time

[AmandineLP]

I joined the room by clicking on it from the directory. No messages were exchanged before, only statuses. Xena is admin and on Matrix.org. Refreshing fixes it

[AmandineLP]

it happened again...

[ara4n]

@erikjohnston this looks worryingly like the HS coughing up ancient events?

[erikjohnston]

I think the last one might be a federation thing (where we hadn't gotten the join before), and a different bug from the first.

[erikjohnston]

So, I can't see anything obvious that would explain this behaviour server side. I think at this point I kinda need the /sync and /messages responses, which I appreciate might be hard to get.

Is there any possibility that vector has incorrectly ordered the responses to multiple /message requests? Alternatively, synapse will send down those events in the state section of /sync?

[ara4n]

@dbkr: is there any chance this is related to the multiple concurrent /sync bug you hit?

On 02/03/2016 16:15, Erik Johnston wrote:

So, I can't see anything obvious that would explain this behaviour server side. I think at this point I kinda need the |/sync| and |/messages| responses, which I appreciate might be hard to get.

Is there any possibility that vector has incorrectly ordered the responses to multiple |/message| requests? Alternatively, synapse will send down those events in the state section?

— Reply to this email directly or view it on GitHub https://github.com/vector-im/vector-web/issues/897#issuecomment-191308406.

[richvdh]

I suspect this is something to do with changes in history_visibility; in particular, events that have shared history_visibility which become visible when you join. But still, it's hard to see why old events would be stuck at the end of the timeline. It would be very useful to have the /events / /sync / /messages requests from this time.

[richvdh]

Amandine saw it again: https://matrix.org/_matrix/media/v1/download/matrix.org/mKQPzAFjFfMQDOrPiujKfRYU

[richvdh]

This bug, in its original guise (messed up timeline on room join), doesn't seem to have been seen for a while. (As opposed to vector-im/element-meta#1491, which is some sort of screwup which happens when synapse decides to backfill an existing room over federation, and is definitely still happening). Is it possible it's gone away?

[ara4n]

yeah, unless @AmandineLP has seen it again (given she seems to be the main progenitor), i think this has been fixed somehow somewhere. Perhaps @erikjohnston might even know where.

[AmandineLP]

I haven't seen it recently

[ara4n]

KILL IT WITH FIRE