Amends c7691842f743f568a073582c8f0cacd6ee188f98, and actually fixes the
other half of QTBUG-130142.
Fix the unittest, it was wrong to begin with, iterating over an empty
string with NoDotAndDotDot, next() will always return an empty string
because `currentFileInfo` has never been initialized.
Pick-to: 6.9 6.8
Fixes: QTBUG-135287
Task-number: QTBUG-130142
Change-Id: I9966428c7a143803e6e934b5970ea6b6afc8a08f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
4fd7d31e09