QAbstractItemModelTester: don't rely on hasChildren()

Dynamic models which use fetchMore to asynchronously fill subdirs
(like KDirModel) return true in hasChildren() for dirs that are expected
to have children (so that the "+" shows in the treeview) but do not
actually have children readily available.
They will be inserted later on once the async listing job is done
(as a result of fetchMore triggering that job).

So QAbstractItemModelTester should use rowCount instead, to find out
if there are children present.

This detected a bug in QConcatenateTablesProxyModel: it returned
a non-zero rowCount for its items, while it's flat.

Change-Id: Idcdc86159f1fc79ed5297075dfcf30c09896287a
Pick-to: 5.15
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

0 files changed, 0 insertions, 0 deletions