Re: Run `M-x list-input-methods` and then scroll down the screen in input method panel using the mouse or arrow key will cause Emacs unresponsive for about 1 minite.

[Hongyi Zhao <hongyi.zhao@gmail.com>]

On Sat, Jun 19, 2021 at 2:57 PM Eli Zaretskii <eliz@gnu.org> wrote:
>
> > From: Hongyi Zhao <hongyi.zhao@gmail.com>
> > Date: Sat, 19 Jun 2021 14:39:46 +0800
> >
> > > > Then run `M-x list-input-methods` and scroll down the screen in input
> > > > method panel using the mouse or arrow key will cause Emacs
> > > > unresponsive for about 1 minute.
> > >
> > > It isn't necessarily strange: Emacs looks for the fonts needed to
> > > display the relevant characters, so if you have a lot of fonts
> > > installed, and some character is not supported, it will take Emacs a
> > > lot of time to scan all those fonts.
> >
> > Thank you for your analysis. That is really my situation. See below:
> >
> > $ fc-list |wc
> >   10597   33360 1138340
>
> If you invoke Emacs with "emacs -Q" and then type "C-h h", how long
> does it take Emacs to display the HELLO file?

It presumably takes the same duration as reported before in this issue.

> And if you then scroll
> down through the HELLO file, do you also see long delays at some
> point?

Seems not.

Another strange thing: the Emacs installed from apt repo doesn't have
this problem.

Regards
-- 
Assoc. Prof. Hongyi Zhao <hongyi.zhao@gmail.com>
Theory and Simulation of Materials
Hebei Vocational University of Technology and Engineering
NO. 552 North Gangtie Road, Xingtai, China