bug#66655: 29.1; Clicking buttons sometimes doesn't work

[Stefan Monnier]

> What will that do if the mouse was moved, then returned to the
> original position before the button is released?

In the sample patch I sent it depends if the original mouse/screen position
still shows the same buffer position.  If it does, then the `up` will
stay as an `up`, otherwise it will turn into a `drag`.
[ At least, that's what I think my code does.  ]


        Stefan