Re: Emacs 27 face :extend attribute not working with pulse.el?

[Adam Porter <adam@alphapapa.net>]

Adam Porter <adam@alphapapa.net> writes:

> Hi,
>
> I'm still using Emacs 26.3 as my main instance, but while testing
> Andrea's native-comp branch, I've also been testing Emacs 28.0.50 which,
> of course, includes the changes from Emacs 27.0.90.
>
> A while back I read on this list about the new face :extend attribute,
> how it required some changes in packages like Magit, etc.  It sounded
> like the issues had been resolved, that setting the :extend attribute
> would restore previous behavior, etc.
>
> However, in my Scrollkeeper package
> (https://github.com/alphapapa/scrollkeeper.el), it does not seem to be
> working.  One of the configurable guideline methods in the package uses
> pulse-momentary-highlight-oneline to highlight a line in the buffer when
> one of the scrolling commands is called (typically by setting a
> background color attribute).  In Emacs 26.3, it works properly: the
> entire visual line, up to the width of the window, is highlighted.  But
> in Emacs 28.0.50, even when the scrollkeeper-guideline-highlight face
> has the :extend attribute set to t, the highlighting does not extend to
> the width of the window.
>
> I think this issue may be in pulse.el, because evaluating this code has
> the same problem:
>
>   (pulse-momentary-highlight-one-line (point))

After further investigation, I've found that setting ":extend t" on the
pulse-highlight-face seems to fix the problem and restore the behavior
seen in Emacs 26.3.

This seems like an obvious, easy fix to restore the previous behavior,
but I don't know if it's the "correct" one, because it appears to have
the side effect of forcing extension even when
pulse-momentary-highlight-one-line is called with a face argument which
does not have ":extend t" set.