bug#52554: 28.0.90; mm-inline-media-tests customization breaks .emacs reading

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: Andreas Schwab <schwab@linux-m68k.org>,  52554@debbugs.gnu.org
> Date: Fri, 17 Dec 2021 09:23:48 +0100
> 
>     >> I'd rather think that custom-save-variable should bind
>     >> print-escape-control-characters to t.
> 
>     Eli> Maybe we should do both?
> 
> In `custom-save-all' perhaps? There are many code paths for saving
> customizations, they donʼt all go via `custom-save-variable'.

If they all go through custom-save-all, then I think it should be done
there, yes.