bug#47974: 27.2; doc-view-mode freezes when used together with global-linum-mode

[Stefan Kangas]

"Raoul Comninos" <revrari@mweb.co.za> writes:

> When trying to view documents using `doc-view-mode' Emacs slows down and 
> eventually freezes. I traced this problem to
> `global-linum-mode' which was set to `t' in my init.el file. I tested this 
> with Emacs -Q and I am able to replicate it. `global-linum-mode' does
> not work with `doc-view-mode'. Emacs does not crash but freezes. One has then 
> to quit Emacs through the
> Windows task manager.
>
> In GNU Emacs 27.2 (build 1, x86_64-w64-mingw32)
>  of 2021-03-26 built on fv-az68-192
> Repository revision: 4e952a7445daa0fb9df229ea61b69ccee3264d4a
> Repository branch: master
> Windowing system distributor 'Microsoft Corp.', version 10.0.19041
> System Description: Microsoft Windows 10 Pro (v10.0.2004.19041.928)

I guess the recipe here is:

0. emacs -Q
1. M-x global-linum-mode RET
2. C-x C-f <foo.pdf>

I can confirm Emacs is very unresponsive, but there is no freeze here.
This is on GNU/Linux and current master.

(I'm not seeing any unresponsiveness with `display-line-numbers-mode',
so a workaround might be to just use that instead.)