[debian-mysql] Bug#961672: Bug#961672: charset files not installed in a mysql-safe location

[Otto Kekäläinen]

Hello!

> /usr/share/mysql/charsets
..
> The location of these files causes the libmysqlclient20 client library
> to consider them charset files from mysql, and it tries to use them.
>
> I think this behavior is wrong, as the charset files do not belong to
> mysql, however it is not immediately causing user-visible issues.

These files are drop-in replacements for MySQL files. The fact that
they in Debian with MySQL version 5.7.26-1 (or any other version that
has ever been in Debian) work as you said without any user-visible
issues is proof that the drop-in-replacement works.

> Things are worse with mysql-8.0, not yet in Debian but packaged in
> Ubuntu. In mysql-8.0 the charset file format is not compatible with the
> older versions, and this causes the client library to segfault when
> trying to use the charset files from mariadb.

I have not checked what packaging changes MySQL 8.0 introduces and in
how many ways it is breaks backwards compatibility, but I guess that
while working on
https://salsa.debian.org/mariadb-team/mysql/-/tree/mysql-8.0/debian/master
those issues need to be addressed when the details surface.

If libmysqlclient21 in mysql-8.0 heavily breaks backwards
compatibility (e.g. major changes in charsets?) then we need to make
sure that the package control properly conflicts with libmysqlclient20
or the equivalent from MariaDB.