check testcase for null before use

[homberghp]

closes #8440

Added test

if (testcase ==null) {
            return;
        }

This will prevent the NPE.

Result should be the same, because when there is no testcase there is no trouble 🥲

---

^Add meaningful description above

Click to collapse/expand PR instructions

By opening a pull request you confirm that, unless explicitly stated otherwise, the changes -

• are all your own work, and you have the right to contribute them.
• are contributed solely under the terms and conditions of the Apache License 2.0 (see section 5 of the license for more information).

Please make sure (eg. git log) that all commits have a valid name and email address for you in the Author field.

If you're a first time contributor, see the Contributing guidelines for more information.

If you're a committer, please label the PR before pressing "Create pull request" so that the right test jobs can run.

PR approval and merge checklist:

1. Was this PR correctly labeled, did the right tests run? When did they run?
2. Is this PR squashed?
3. Are author name / email address correct? Are co-authors correctly listed? Do the commit messages need updates?
4. Does the PR title and description still fit after the Nth iteration? Is the description sufficient to appear in the release notes?

If this PR targets the delivery branch: don't merge. (full wiki article)

[mbien]

this could work or throw a NPE a few calls later - dependent if that parameter is allowed to be null or not.

Given that this is about ant freeform projects, I am wondering if it is having problems with junit 4 suites in general. Would be good to find a reproducer and check that this is working.