user.dir system property sideeffect of surefire-plugin setting forks to 0?

[Svante Schubert <sv...@apache.org>]

There is an interesting scenario, where a Maven project is failing to run
the maven-rat plugin (not finding some files) due to the user.dir system
property is being altered from the original project root patch (the calling
directory) to the sub-sub project path where the pom.xml is defining
<forkCount>0</forkCount>. This rat anomaly vanishes as soon I remove the
<forkCount>0</forkCount>.
A quick grep revealed several user.dir manipulations, I suspect the
surefire plugin to be the origin of the anomaly.
A description of the use case to reproduce and more details have been
posted to the rat plugin mailing list, see
https://lists.apache.org/thread/dmfg87fgtfyzoog20rmmj5nnds9kwotq

Perhaps one of you is curious to take a quick look at it.

Thanks in advance and greetings from Berlin!
Svante