I am not using any library to access mariadb, I am just using the protocol directly as described here.
The issue is when creating a prepared statement (using the binary protocol).
COM_STMT_PREPARE_OK returns the wrong column type in the column description packet.
This only happens with mariadb 10.3.x. It works fine with 10.2.x and prior versions.
There's only one column definition sent, since there's only one param in the statement.
The column definition now returns a column type of 0x06 (NULL).
With all previous versions (10.2.x and earlier), it returns 0xfd (VARSTRING), which is correct, it's the type of the name column.