Re: Question: add-face-text-property for 'font-lock-face?

[Eli Zaretskii]

> From: Qiantan Hong <qhong@mit.edu>
> Date: Sun, 29 Aug 2021 04:13:40 +0000
> Accept-Language: en-US
> 
> Users of crdt.el report that crdt-visualize-author-mode (which use 
> font-lock-face to color code author of texts)
> conflict with faces from other modes. Apparently there are more than 1 mode 
> which sets this text property.
> 
> Is there some way to add-face-text-property to 'font-lock-face property, 
> i.e. adding new face attributes instead of overwriting any existing face?
> add-face-text-property doesn’t seem to work because 'font-lock-face will just 
> override ‘face.

I don't think I understand well enough what you want to do, but in
general, you change a face's attribute by using set-face-attribute.