RE: Negative positions in frame parameters

[Drew Adams]

BTW, apparently the `invisible' `display' property affects frame positioning.

I use dired-details.el, which puts an overlay on all of the Dired fields except
the file name. The overlay has `evaporate' = t, `invisible' = t, and
`before-string' = "".

As a result, if I do (make-frame '((left . -10) (top . -10))) with such a Dired
frame current, it positions the new frame as if its right edge were the same as
the original frame before hiding the details.

That is, the narrow frame (because no permissions, time etc. are shown) appears
in the middle of the screen - it does not have its right edge 10 pixels past the
screen right edge. It is not the right edge of the actual frame that is
positioned correctly, but the right edge of the frame as it would have appeared
without hiding anything.

Dunno if this should be considered a bug or not, but it's interesting. ;-)