[BUG] :debug faces does not work from inside a command.

[Screwtapello]

Version of Kakoune

v2024.05.18-188-g9c458c50

Reproducer

kak -n -e 'def a "buffer *debug*; debug faces"; a'

Outcome

The *debug* buffer contains:

Faces:

Expectations

The *debug* buffer contains:

Faces:
 * Default: default,default,default
 * PrimarySelection: white,blue,default
 * SecondarySelection: black,blue,default
 * PrimaryCursor: black,white,default
 * SecondaryCursor: black,white,default
 * PrimaryCursorEol: black,cyan,default
 * SecondaryCursorEol: black,cyan,default
 ...

Additional information

Just running kak -n -e 'buffer *debug*; debug faces' works fine, it's wrapping it in a command that causes the problem.

git bisect indicates 1c71fc0 as the cause, "Add local scope to user commands", from 2024-04-29. debug faces calls context.faces().flatten_faces() to get the list of faces to write, which I guess is empty inside a local context rather than inheriting from the parent context.

[Screwtapello]

As for why somebody might want to call debug faces from a command, I use it to quickly preview all the faces in a colorscheme:

https://discuss.kakoune.com/t/display-all-faces-in-the-current-color-scheme/1178