Dendrite won't allow invitation rejections unless federation is turned on.

[gleachkr]

Background information

• Dendrite version or git SHA: 2c9a390
• Monolith or Polylith?: Monolith
• SQLite3 or Postgres?: sqlite3
• Running in Docker?: no
• go version: 1.16 linux/amd64

Description

Dendrite won't allow invitation rejections unless federation is turned on.

Steps to reproduce

• set disable_federation: true in dendrite.yaml.
• issue an invitation to a room.
• attempt to reject this invitation by accessing the relevant leave endpoint (I was doing this with the js-sdk).

The server then throws a 400 bad request, and the SDK gives the error "failed to leave room ... through 1 server(s)".

The following error appears in the systemd log:

Jun 12 16:41:24 dendrite-1 dendrite-monolith-server[465449]: time="2021-06-12T16:41:24.375703525Z" level=warning msg="r.federation.MakeLeave failed" func="PerformLeave\n\t" file=" [github.com/matrix-org/dendrite/federationsender/internal/perform.go:463]" error="Get \"matrix://populus.open-tower.com/_matrix/federation/v1/make_leave/ ETC
Jun 12 16:42:04 dendrite-1 dendrite-monolith-server[465449]: time="2021-06-12T16:42:04.752656729Z" level=warning msg="Outgoing request failed" func="DoHTTPRequest\n\t" file=" [github.com/matrix-org/[email protected]/client.go:495]" error="Get \"matrix://populus.open-tower.com/_matrix/federation/v1/make_leave/ ETC

Switching disable_federation to false appears to resolve the problem. The problem only seems to arise when rejecting an invitation, not when leaving a room that has been joined, but it was completely reproducible under those conditions.

[kegsay]

Possibly related: #1743

[kegsay]

@gleachkr please can you try this again on e80098e - it should be fixed now.

[gleachkr]

Yes, seems to be fixed. Thanks!