To be able to see the level of coverage with the current test suite,
do the following:

  - Make sure gcov is installed
  - Compile the MariaDB distribution with -DENABLE_GCOV=1
  - In the mysql-test directory, run this command: `./mysql-test-run --gcov`
  - see var/last_changes.dgcov for the coverage of uncommitted code
  - see `./dgcov -h` for more options