...if a PMF connection had already happened. Since UniqueConnection
isn't implemented for non-PMFs (functors and lambdas aren't comparable,
even if static member functions or non-member functions are), we pass a
null pointer for comparison argument. The disconnect() code already
protected against a null pointer there, but not the connect code path
with Qt::UniqueConnection
Change-Id: I87e17314d8b24ae983b1fffd145324beced0494d
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
Reviewed-by: Dario Freddi <dario.freddi@ispirata.com>