Reported by :
did a great job helping me to transform the current Debian Sid packaging on MariaDB 10.0 to use the socket auth for the root user, thus no mysql/mariadb root password is needed anymore
This new system works great for new installs, but users who had been using a root account with a password get confused when it suddently disappears during an upgrade, eg. https://bugs.launchpad.net/ubuntu/+source/mariadb-10.0/+bug/1447808
The Debian mariadb-server-10.0.preinst and .postinst scripts should be engineered so that they detect if an upgrade is taking place (if there was a previous root password or if the database is blank) and in those cases where a root password did previously exist, it should still be possible to log in also using the password.
Daniel black drafted https://github.com/ottok/mariadb-10.0/pull/23/files but I don't understand how it solves this situation.