Preserve appearance of collapsed outline headings until right window edge
An outline heading does not extend to the right edge of the window when its body is collapsed. This is unfortunate when the used face sets the background color or another property that is visible on whitespace. This package adds overlays to extend the appearance of headings all the way to the right window edge.
outline-minor-mode by itself does not
highlight headings. The
outline-minor-faces package implements
that and is required by this package.
(use-package backline :after outline :config (advice-add 'outline-flag-region :after 'backline-update))