QFileSystemModel leaks QFileWatcher paths

Apply the attached diagnostic patch to Qt.
1) Launch the examples/itemviews/dirview example and watch paths being added to QFileSystemWatcher as you navigate them. They are never removed
even if the directories are closed
2) Create an application that provides a flat view using QFileSystemModel::setRootPath() and QItemView::setRootIndex . Note that the watchers are also leaked if you call
QFileSystemModel::setRootPath().

Not sure if 1) is fixable, but 2) is evil.