Icon Theme Specification - clarification of "hicolor" fallback

Hello,

I’m looking at our Freedesktop Icon Theme support in Qt, and I’m trying to clarify whether implementors are allowed to reorder “hicolor" to the end of the lookup list if the theme itself specifies it as a parent.

The spec [1] says for the Inherits property:

"If no theme is specified implementations are required to add the "hicolor" theme to the inheritance tree. An implementation may optionally add other default themes in between the last specified theme and the hicolor theme."

and for icon lookup:

"The lookup is done first in the current theme, and then recursively in each of the current theme's parents, and finally in the default theme called "hicolor" (implementations may add more default themes before "hicolor", but "hicolor" must be last).”

But if the theme itself specifies:

Inherits=foo,bar,hicolor

Must the implementation then respect that, making the order:

foo -> bar -> hicolor -> implementation_fallback -> hicolor

Or can the implementation reorder hicolor to the end:

foo -> bar -> implementation_fallback -> hicolor

Thanks!

See https://codereview.qt-project.org/c/qt/qtbase/+/477299/1 for reference.

tor arne

[1] https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html