When using read_default_file to specify connection credentials, the host option is not being picked up, although other options are. The client library then attempts to connect to the default local socket, which fails. When the host is passed directly in the code, it is correctly picked up.

After some debugging and building from source, I suspect the issue was introduced in https://github.com/MariaDB/mariadb-connector-c/commit/184a16d2f1d0bb24bea6bcf23e1604093fef8f93. When applying the attached patch and thus reverting part of the commit, the host is correctly picked up again, although I am not sure what exactly the purpose of said commit is and whether the patch interferes with that.