Order of fonts returned by list-fonts

[Kévin Le Gouguec]

Hello Emacs,

My distro ships with Noto Color Emoji 13.1.  I have installed version 14
under ~/.local/share/fonts.  fc-match seems to prioritize the latter:

$ fc-match -f '%{fullname} %{file}\n' "Noto Color Emoji"
> Noto Color Emoji /home/peniblec/.local/share/fonts/NotoColorEmoji.ttf

Emacs, however, seems to favour the former:

(find-font (font-spec :family "Noto Color Emoji"))
> #<font-entity ftcrhb GOOG Noto\ Color\ Emoji nil iso10646-1 regular
> normal normal 0 nil 100 0 ((:font-entity
> "/usr/share/fonts/truetype/NotoColorEmoji.ttf" . 0))>

(list-fonts (font-spec :family "Noto Color Emoji"))
> (#<font-entity ftcrhb GOOG Noto\ Color\ Emoji nil iso10646-1 regular
>  normal normal 0 nil 100 0 ((:font-entity
>  "/usr/share/fonts/truetype/NotoColorEmoji.ttf" . 0))> 
>  #<font-entity ftcrhb GOOG Noto\ Color\ Emoji nil iso10646-1 regular
>  normal normal 0 nil 100 0 ((:font-entity
>  "/home/peniblec/.local/share/fonts/NotoColorEmoji.ttf" . 0))>)

Could this be considered a bug?  I didn't dig into the code yet, beside
looking at font_list_entities (which led me to restart with
EMACS_FONT_LOG set; unfortunately font-show-log doesn't have much to say
about how font files are searched).

I don't know if my expectation (that Emacs and fc-match should agree on
how files are prioritized) is warranted; I know that Emacs relies on
Fontconfig APIs to some degree, but I'm sure there is more complexity
lurking under the hood.

I figured I'd ask around if the above makes sense to someone before
putting my spelunking hat on :)


FWIW: I originally "solved" the problem by uninstalling the version
shipped by my distro; unfortunately, today's upgrade seems to have
brought it back, presumably because another package has started
depending on it.

FWIW²: the bigger-picture fix would probably be to send a patch to the
distro to migrate to Noto Color Emoji 14; I might get to that at some
point, but I still would like to understand what's going on with Emacs.


In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.31, cairo 
version 1.16.0)
 of 2022-01-01 built on amdahl30
Repository revision: 1d3020908b4e4ff398c3faed9321aa4932fbaad1
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101003
System Description: openSUSE Tumbleweed

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