bug#43835: 28.0.50; auto-hscroll-mode/current-line + show-paren-mode + gnus-summary-mode = bug

[Eli Zaretskii]

> Date: Wed, 07 Oct 2020 15:46:42 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 43835@debbugs.gnu.org
> 
> Could the reason for this problem somehow be related to
> gnus-horizontal-recenter, which is called by gnus-recenter basically
> whenever you do something in the summary buffer?  If you disable this
> horizontal recentering (e.g., by setting gnus-auto-center-summary to
> the value 'vertical'), does the problem go away?

I think when auto-hscroll-mode is non-nil, gnus-horizontal-recenter
should do nothing, instead letting the automatic hscrolling to do its
thing.  At least when auto-hscroll-mode's value is 'current-line',
because in that case setting the window's hscroll value does the wrong
thing.