bug#31915: 26.0.50; highlight-regexp does not highlight regexp

[Markus Triska <triska@metalevel.at>]

Eli Zaretskii <eliz@gnu.org> writes:

> Actually, that buffer is in Fundamental mode, where there's no
> font-lock.  Somehow, I suspect you already know that.

In the snippet I posted, I used the variable font-lock-mode to test
whether font-lock is enabled. Its documentation states:

    Non-nil if Font-Lock mode is enabled.

Is this documentation valid? If not, could you please adapt it, or -
alternatively - make the implementation match the description?

> Would it suffice to say "Note that in Fundamental mode, there's no
> font lock, so overlays are always used"?  Or did you mean something
> else?

Personally, I suspect that adding this would not cover all cases. I get
this impression from looking at hi-lock-set-pattern:

      (if (and font-lock-mode (font-lock-specified-p major-mode))

This condition seems to be different from what is documented.

Thank you and all the best,
Markus