bug#51590: follow-mode is broken with header-line and tab-line

[martin rudalics]

> (posn-area (posn-at-x-y (1- (window-pixel-width)) 0))
>
> currently gives 'nil' regardless of whether it's done with a header or
> tab line and
>
> (posn-area (posn-at-x-y
>          (1- (window-pixel-width))
>          (1- (window-pixel-height))))
>
> gives 'nil' on the mode line.  Only when I remove _both_ fringes and the
> vertical scroll bar I get the expected results.  This _is_ a bug and we
> should fix it.

I think the attached patch should fix that modulo some ">=" and "<"
glitches.

martin

posn-at-x-y.diff
Description: Text Data