[debian-mysql] Bug#926231: Bug#926231: Bug#926231: mariadb-server-10.3: dpkg configure error - upgrade from mysql

[Otto Kekäläinen]

I think I've found out what is going on here. If one has mysql-5.7
installed, one needs to run mysql_upgrade plus some extra conversions
to get the database in a working state.

I rename the socket auth plugin in
https://salsa.debian.org/mariadb-team/mariadb-10.3/commit/15935cff592b8bccecf835ac4322784dd5da3e89
However also upstream mysql_upgrade needs to run as it does the
Password column rename in two potential places:
- https://github.com/MariaDB/server/blob/10.3/scripts/mysql_to_mariadb.sql
- https://github.com/MariaDB/server/blob/10.3/scripts/mysql_system_tables_fix.sql

See also https://jira.mariadb.org/browse/MDEV-11170?focusedCommentId=126486&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-126486

A manual workaround at the moment is:
shell 1$ /usr/bin/mysqld_safe
190417 18:58:17 mysqld_safe Logging to syslog.
190417 18:58:17 mysqld_safe Starting mysqld daemon with databases from
/var/lib/mysql

shell 2$ /usr/bin/mysqld_safe
190417 18:58:17 mysqld_safe Logging to syslog.
190417 18:58:17 mysqld_safe Starting mysqld daemon with databases from
/var/lib/mysql
...

After this apt install -f will complete. The above should somehow be
incorporated into the mariadb-server-10.3.postinst file.