500 error when sending `m.room.canonical_alias` where 400 is expected

[t3chguy]

Description

Sending an m.room.canonical_alias event with a non-string alias field should return a HTTP 400 as per https://spec.matrix.org/v1.16/client-server-api/#put_matrixclientv3roomsroomidstateeventtypestatekey for The sender's request is malformed. but actually returns a 500 Failed to send event! (MatrixError: [500] Internal server error (https://matrix-client.matrix.org/_matrix/client/v3/rooms/!EdGGoamBVXVcYvqdPL%3Amatrix.org/state/m.room.canonical_alias/))

Steps to reproduce

• Send m.room.canonical_alias with content {"alias": {"foo": "bar"}}

Homeserver

matrix.org

Synapse Version

{"server_version":"1.142.0rc4 (b=matrix-org-hotfixes-priv,2c3f64e44c)"}

Installation Method

I don't know

Database

Unknown

Workers

I don't know

Platform

Unknown

Configuration

Unknown

Relevant log output

Unknown

Anything else that would be useful to know?

No response