Push rules do not get copied to the new room when it is upgraded

[matrixbot]

This issue was originally created by @ShadowJonathan at matrix-org/dendrite#2863.

This fails a sytest called $user_type user has push rules copied to upgraded room

It asserts that push rules are copied to the new room when it has been upgraded (and the user joins the new room)

See the following wording, where the spec recommends this:

When a user joins the new room, the server should automatically transfer/replicate some of the user’s personalized settings such as notifications, tags, etc.

Background information

• Dendrite version or git SHA: b13cb43

[matrixbot]

This comment was originally posted by @ShadowJonathan at matrix-org/dendrite#2863 (comment).

(Whoops)

@S7evinK highlighted for me that Dendrite does indeed pass the sytest, but after some research, I found out that the sytest is very likely faulty.

Furthermore, when scouring the dendrite codebase, I could not find a single ounce of behaviour (searching on strings "upgrade" and "tombstone") that referred to an after-upgrade personal user settings migration, if that user joins such an upgraded room.