Description:
============

The --with-ndbcluster-only option for mtr is expected to make mtr run
only ndb tests.

One can run

   ./mtr --with-ndbcluster-only --suite=main

and it will run tests although there are no ndb tests in main suite.

Bug is in mtr_cases.pl:

    sub collect_one_test_case {
    ...
     # This is not a ndb test
     if ($opt_with_ndbcluster_only) {
       # Only the ndb test should be run, all other should be skipped

The variable $opt_with_ndbcluster_only is never set.

while sub collect_option will set the variable $with_ndbcluster_only if
--with-ndbcluster-only is given.

Also the description of the option is wrong

    with-ndbcluster-only  Run only tests that include "ndb" in the filename.

Whether a test is a ndb test or not is decided upon if certain files are
sourced or not in test:

    include/have_ndb.inc
    include/have_multi_ndb.inc
    include/ndb_master-slave.inc

How to repeat:
==============

$ ./mtr --with-ndbcluster-only main.union
...
[ 50%] main.union                     [ pass ]  11345

Expected is
$ ./mtr --with-ndbcluster-only main.union
...
[ 50%] main.union                     [ skipped ]  Only ndbcluster tests

Fix:
====

Rename $opt_with_ndbcluster_only to $with_ndbcluster_only.

Rephrase

  with-ndbcluster-only  Run only tests that include "ndb" in the filename.

to

  with-ndbcluster-only  Run only ndb tests.

Reviewed-by: Magnus Blåudd <magnus.blaudd@oracle.com>