bug#37774: 27.0.50; new :extend attribute broke visuals of all themes and other packages

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: rudalics@gmx.at,  andreyorst@gmail.com,  37774@debbugs.gnu.org
> Date: Sun, 20 Oct 2019 18:42:35 +0300
> 
> >>               (save-excursion
> >>                 (goto-char rbeg)
> >>                 (save-match-data
> >>                   (while (re-search-forward "\\s-*\n\\s-*" rend t nil)
> >>                     (remove-text-properties (match-beginning 0)
> >>                                             (match-end 0)
> >>                                             '(font-lock-face t)))))
> >
> > Yes, I think so, but maybe leave this code in place conditioned by the
> > relevant face being extended, in case users customize them?
> 
> I noticed that this code is still needed because ':extend nil'
> still highlights the final newline at EOL, but this code removes
> highlighting from newlines.

Right.