QInputMethod works on focusObject, not focusWidget. These two
are not always the same, and sometimes the focusObject is also
NULL. In either case, we should not tell QInputMethod to
commit, reset or otherwise emit signals based on the internal
state of widgets that are not the focus object.
This led to a crash on iOS, since we got a call to
cursorRectangleChanged when focus object was NULL, which
the code didn't (and shouldn't need to) take into account.
Change-Id: I54e40d7ec35210ba6599a78c5a8c7f982a1c3dbb
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>