Kévin Le Gouguec <kevin.legouguec@gmail.com> writes:

> 1. emacs -Q CONTRIBUTE
> 2. C-x v g
> 3. move to "461cb9217d8 CONTRIBUTE (Paul Eggert 2019-05-25 10)"
> 4. =
> 5. move to the first removed line ("Briefly, …")
> 6. C-SPC
> 7. C-f C-f …
>
> As long as point does not go past the refinement (before the comma), the
> region's background has the region face's background.
>
> Once point moves past the refinement, only non-refined parts keep the
> region face's background; refined parts keep the refinement background.

I'd say "one picture is worth a thousand words", but… obviously this
saying dates from before we learned how to encode words and pictures
into bytes.