Adjust the "CSV file to MTR test converter" to the behaviour of mysqldump
Convert "Init DB","<schema>" to "USE <schema>"
Detail:
- mysqldump causes entries within the CSV file like
"Init DB","<schema>"
check if <schema> exists
collect names of tables residing within <schema>
various SELECTs on tables residing in <schema>
- the old converter filtered the "Init DB","<schema>" out
and the various SELECTs fail with "unknown table" in case
the current (session) schema is <> "<schema>"