mythtv-database won't cleanly upgrade during a dist-upgrade

[Mario Limonciello]

Currently when running through a dist-upgrade procedure, mythtv-database will cause the process to fail if the mysql-server is locally setup. Mythtv-database connects to this server to complete its post install configuration. Since mysql-server is stopped during the upgrade, it's not able to actually complete post install configuration.

There are several bugs opened that are caused by this issue: #67696, 41339, 58155, 68400. Any user that has mythtv-database installed in Dapper, and moves up to edgy will have a failed upgrade unless they remove mythtv-database prior to upgrade.

[Mario Limonciello (superm1)]

Attached is a patch that will clean up this problem. Instead of failing when not being able to connect to mysql-server, it will present the user with an update-notification bubble explaining what happened and what needs to be done after the upgrade (dpkg-reconfigure mythtv-database).

[Mario Limonciello (superm1)]

There was some previous discussion about what to do with this issue in bug 68400 with Michael Vogt.
"Hello Mario!

Thanks for looking into this issue. Unfortunately the update-manager
can't control the odering of unpack/configure in dpkg during the
install directly. This is all be done according to the dependencies of
the packages. The dependencies of the mytv-database are in such a way
that mysql server is unpacked (and therefore stopped) and it is
restarted only when it is configured again by dpkg (which happens after
mytv-database is configured).

So what happns is:

unpack mysql-server (stops the server)
unpack mythtv-database
configure mytv-database (tries to connect)
configure mysql-server (starts the server)

To fix the issue we either need to ensure that mytv-database is only
configured after mysql-server was configured. In theory a pre-depends
could be used for this, but because mytv-database does not depend on
mysql-server directly but only on the client this is not practical
(server might be on a different machine etc).

The other option is that the mytv-database postinst does not fail if it
can't connect to the database but echo a warning to run "dpkg-
reconfigure mythtv-database" (or even use a post-install notification or
a debconf note) and keeps going. Looking over the postinst script it
seems to be setting up a database (should be not needed on upgrades) and
converting from some older db format to a newer one. I don't know if
that is a issue during the upgrade. But if not I would only print out a
warning instead of letting the postinst fail when no database connection
is available.

Please let me know what you think!

Cheers,
Michael
"