RE: focus-follows-mouse should be nil by default on MS Windows

[Drew Adams]

    > But you've explicitly changed the Windows default, so it's
    > probably OK to require you change the Emacs var as well.
    > Maybe the setting can even be extracted from the registry?

    The problem is, the name of the registry entry that controls this
    changes with every version of Emacs.

    Anyway, I cannot see any difference in behavior of, say, "C-x 5 o"
    (which calls select-frame-set-input-focus, which Drew cited) that
    depends on the value of this variable.  Can someone post a recipe to
    show when this variable matters on Windows?  If not, I'm inclined to
    document that this variable has no effect on w32 frames, and leave it
    at that.

Documenting that would seem to be wrong, as the example I sent shows. In
that example, if the value is nil, then the mouse position does not get set;
if non-nil, it gets set. So I don't see why we would document that the
variable's value has no effect on w32 frames.