Cycling smart pointers when creating lambda signal-slot connection

[Alex2772]

auto surface = _new ...;
connect(clicked, surface, [surface]() {
  ...
});

In this example, surface is referenced in signal-slot connection lambda, causing the surface to never destroy by itself.

[Alex2772]

Workaround:

auto surface = _new ...;
connect(clicked, surface, [surface = surface.get()]() {
  ...
});

At least there are should be diagnostics for that.