OS toolbar affects frame width and (get-display-size)...

[Don Green]

In the case where there exists a vertical Operating System toolbar:

Creating a frame width that is half of the width given by (get-display-size), then moving the resulting window to the right and left of the screen you can see that if you had 2 windows of the same size they would not touch each other as you would expect.
For some reason, dividing the total pixel width in HALF, DOES NOT give 2 windows that will fill the space.
;Instead there is a mysterious gap that happens to be about the width of the O.S. vertical toolbar.

Can anyone explain?

Thanks