`Array.prototype.splice` will return the array of removed items, not a new array. The array operated on is actually modified in-place.
This was causing a few weird things to happen: https://github.com/vector-im/riot-web/issues/4511 and https://github.com/vector-im/riot-web/issues/4533. This should fix both of them but it is concerning that doing the tab completion is required to reproduce. Let's just see how this goes before closing the issues.
Thanks @turt2live for reproducing both bugs, giving enough information for a fix :)
Accepting an invite would cause a room to arrive via /sync only for it to throw an error in the auto complete code and cause the client to go wibbly (infinite spinner or preview bar).
The logs that lead to the debugging of this are https://github.com/matrix-org/riot-web-rageshakes/issues/239
Hopefully the error being throw isn't totally unrelated but looking at the sync handling for inviteRooms in sync.js, new rooms are stored and _then_ the Room event is emitted. The Room event could trigger setUserListFromRoom, which is where the bug was. So the room should have been stored regardless of this bug and the client should have been recoverable by swapping away and viewing the room again.
Which are:
- the emoji to complete is at the start of the query
- there is a whitespace character before the emoji
- there is an emoji before the emoji (so that several emoji can be input in-a-row)
Fixes https://github.com/vector-im/riot-web/issues/4498 (although it seems to be fixed through some other fix)
which is now https://github.com/vector-im/riot-web/issues/4537 <- there.
This does two things:
- Track which query was the most recent one requesting completion and only process completions for that one. (In this case the empty string "" doesn't have any completions but we still track it so that previous calls with non-empty queries would not race and cause completions to be shown when we actuall don't want any.)
- Make the "do we want to show the AutoComplete box?" logic a bit more sane
I thought about adding separate dispatches to prevent confusion but if anyone adds anything that listens to existing dispatches, they really ought to be grep-ing the world for said dispatch actions.
