Connecting to nullptr, or connecting to a non-signal PMF, would result
in a QFuture which would never finish. Catch these cases and handle
them.
Windows+MSVC for some reason fails the test. I can't entirely understand
why, so I've marked it as XFAIL, with QTBUG-101761 to track it.
Change-Id: I314980e7e9b7156d8cddd3b33d5cbf1d0bcd6116
Pick-to: 6.2 6.3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
5089db0303