Re: Overlay behavior change

[Eli Zaretskii <eliz@gnu.org>]

On July 8, 2020 11:14:25 AM GMT+03:00, "Gregory Heytings via Emacs development discussions." <emacs-devel@gnu.org> wrote:
> 
> Hi,
> 
> Since at least Emacs 21, overlays between two buffer positions, when
> these 
> two positions are on different lines, extend to the right border of
> the 
> window.  In Emacs 28.0.50 this is not the case anymore, overlays
> extend 
> only one character position after the last character of the line. 
> Sample 
> code (put the cursor on, say, 'lambda' and press C-t):
> 
> (global-set-key
>   (kbd "C-t")
>   (function
>     (lambda ()
>       (interactive)
>       (let* ((start (point))
>              (end (progn (save-excursion (forward-line 5) (point))))
>              (o (make-overlay start end)))
>      (overlay-put o 'face '(:background "green"))))))
> 
> Is this change intentional?  It does not seem to be documented in the 
> NEWS, and I did not find it in the ChangeLogs either (but perhaps I
> did 
> not look carefully enough).  How can one get the previous default 
> behavior?

Yes, this is an intentional change: faces are no longer by default extended to end of line.  If you really need that, use the ':extend' attribute of the face.

This is in NEWS for Emacs 27, I guess you just didn't know which keyword to look for.