From: Stefan Monnier<monnier@iro.umontreal.ca>
Cc: Eli Zaretskii<eliz@gnu.org>,66732@debbugs.gnu.org,
dominik@honnef.co, Yuan Fu<casouri@gmail.com>
Date: Mon, 18 Dec 2023 14:12:02 -0500
I'm surprised that 42 behaves differently from t.
The display code in C tests only for nil or non-nil, but jit-lock.el
tests against a literal t in a few places. (And don't forget about
the special value 'defer' we use.)
What we really need here is to force the redisplay to consider that this
part of the buffer needs to be re-rendered.
AFAIU, it will only re-render that part of some of the faces changed.