hs.layout.apply is confused by screens that are higher than the main one

[farcaller]

Here's a sample session with one of my screens:

> screens.vertical:frame()
hs.geometry.rect(2560.0,-733.0,1440.0,2560.0)
> hs.grid.getGrid(screens.vertical)
hs.geometry.size(6,7)
> hs.inspect(hs.grid.getCell('0,0 1x1', screens.vertical))
{
  h = 365.71428571429,
  w = 240.0,
  x = 2560.0,
  y = -733.0
}

if I use this frame in gs.layout.apply, the window is positioned in the very bottom of the screen instead of the top. I believe that happens because of https://github.com/Hammerspoon/hammerspoon/blob/master/extensions/layout/init.lua#L231 but I see no logical explanation for that code.

Any hints on how to fix this?