The code in 4696e9dbaa was incorrect. It is perfectly valid to call
these methods with row=-1 column=1 parent=some_index, this is exactly
what happens in QListView and QTableView. Child row/column is only for
trees.
Move the coordinate mapping from QSortFilterProxyModel into a new
mapDropCoordinatesToSource internal method, used by QAbstractProxyModel.
Task-number: QTBUG-39549
Change-Id: I3312210473d84b639cbe4c01f70ea36437db3e91
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Stephen Kelly <steveire@gmail.com>
736ac19156