Previously, we skipped setting the list of subscribers to the channel,
which could result in problems if any messages had been posted there
in the past (e.g. because the channel used to have members, but now
doesn't). It could be correct to skip importing dead channels
altogether, but probably simpler is to just set an empty subscriber list.
Previously, our logic to handle Mattermost's "replies" feature didn't
copy the right fields for private messages, where `channel_members` is
included on the message body rather than a `channel` name.
Fixes#1727.
With the server down, apply migrations 0245 and 0246. 0246 will remove
the pub_date column, so it's essential that the previous migrations
ran correctly to copy data before running this.
It's not clear to me how this is intended to work in Mattermost's
system in that they don't document this behavior, but some users have
`null` as their list of teams, and presumably are not meant to be
included in any team at all.
Tim Abbott
Vishnu KS
Rishi Gupta
Mateusz Mandera