Re: Question about display engine

[Eli Zaretskii]

> Date: Sat, 14 Sep 2019 22:42:07 +0200
> From: Ergus <address@hidden>
> Cc: address@hidden, address@hidden
> 
> >I implemented this in the face_at_buffer_position but in the same
> >function (handle_face_prop_general) there is a function called
> >face_at_string_position equivalent to face_at_buffer_position... is it
> >possible in some conditions to reach that part of the code at eol? if
> >so I will need to modify that one too maybe right?

Yes, it's possible.  You need to arrange for a display string or an
overlay string with en embedded newline.

> >The filter now in merge_ref only works when !CONSP(ref_name). As it only
> >bypass the extra parameter to merge_named... it this right in the
> >general case?

I think we should support all the cases, otherwise the feature will
behave inconsistently, and we will get bug reports.

> Could you suggest (if any) if there are some conditions we can use to
> avoid the call to handle_face_prop_general in some cases?

Why, did you see any tangible slow-down of redisplay due to these
changes?