This has been broken forever, just like generic signal
disconnection. It didn't use to show up before because in Qt 4,
QObject's destructor would not call disconnectNotify().
Just like in the previous commit, we need to verify whether the signal
was disconnected from the last receiver. A wildcard disconnect might
be disconnecting only from a specific receiver.
Task-number: QTBUG-29498
Change-Id: I0790128ea878fdf3ac563c99d96c6aa7d270e9a3
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>
537679cb12