Re: 'M-o' ('facemap-keymap') has now been removed until March 10th 2021

[Gregory Heytings <gregory@heytings.org>]

>> Does it?  AFAICS, font-lock-unfontify-region does not "remove _all_ 
>> text properties", it uses remove-list-of-text-properties, which 
>> "removes _some_ properties from text", namely those of font-lock-mode.
>
> Sure, you're right that it does not remove *all* text properties per se. 
> It removes, let's say, "all that it can" which is more than "all that is 
> intended".
>

Please provide a recipe to demonstrate when this actually matters.

>> It allows you to toggle font-lock-mode correctly, which M-x 
>> font-lock-mode can't do.  Try the following: emacs -Q, unless, M-., 
>> M-h, M-w, C-x b RET, M-x text-mode, C-y, M-x font-lock-mode.
>
> This is again correct behaviour.  When you yank the defun from an 
> emacs-lisp-mode buffer into a text-mode buffer, you're inserting text 
> with (most of) its text properties, except for the property `(fontified 
> . t)' because within the context of *this* buffer, the text properties 
> have not been applied with font-lock-mode and so this would be false and 
> prevent font-lock from doing its work.
>

This is not the problem here.  The problem is that M-x font-lock-mode 
(last part of the recipe) is supposed to turn font-lock-mode off, yet the 
font-lock-mode fontification remains.

>
> I hope this clears things up for you. Unless there's any outside 
> objection I'm going to fix up the command in master to reflect as pasted 
> above.
>

I strongly object, there's no need to "fix" a working command to make it 
worse.