Keyboard search in QAbstractItemView (including QComboBox's view) breaks on the space character

If an item in a combo contains a space, then opening the combo and starting to type the text for that item stops working when hitting the space.

Unit test showing the problem: http://www.davidfaure.fr/kde/qaiv_keyboard_search_unittest.diff

The problem is that Key_Space is also used to toggle selection, I'm pretty sure... but while that makes sense in treeviews, it is not useful in a combobox popup.