#2974: Add overrideGroupsFromCliInParentChildXml test

[dr29bart]

#2974: Add a test method for "Regression in -groups CLA"

Closes #2974

[krmahadevan]

@dr29bart - are you also planning to add changes to fix this issue? I ask because if this PR is containing a test that will reproduce the problem then it cannot be merged since it sill start breaking the build.

[dr29bart]

@krmahadevan unfortunately, I don't have a solution. The PR is a just sample of test case for the bug.
I am ok closing this PR without merging it.

[juherr]

@dr29bart The fix should be easy. Do you want to try a fix?

You think it is a regression. Could you tell us when the behavior changed?
The documentation is not precise enough about the expected behavior: addition instead of overriding could be a valid behavior too. In such cases, we prefer to choose the historical behavior.
The fix should include a documentation update too.

[dr29bart]

The 'groups' parameter overrides any defined groups in parent and child xml files in 7.3.0
Starting with 7.4.0 the parameter does not affect scope defined in xml files.

@juherr the behavior has changed in 7.4.0 with this commit:
9c6cb87#diff-c9ad087b236ef4e9750660f8daa935b53c2356a437d3bf5d069ba370e8994cf6R499
It initializes m_currentRun

m_currentRun = new XmlRun();

which then affects condition in XmlSuite#getIncludedGroups:

    if (m_xmlGroups != null && (m_xmlGroups.getRun() != null)) {
      return m_xmlGroups.getRun().getIncludes();
    }

There is XmlTest#setIncludedGroups which works with xmlGroups,I tried to use the same approach for XmlSuite#setIncludedGroups. Please let me know if there is a better way to address the issue.