Subject: bug#36564: 27.0.50; Wrong number of errors in compilation mode-line

From: Stefan Monnier <[email-masked]>
Date: Thu, 11 Jul 2019 18:32:10 -0400

> --- a/lisp/progmodes/compile.el
> +++ b/lisp/progmodes/compile.el
> @@ -2245,6 +2250,8 @@ compilation-filter
>                (unless comint-inhibit-carriage-motion
>                  (comint-carriage-motion (process-mark proc) (point)))
>                (set-marker (process-mark proc) (point))
> +              ;; Update the number of errors in compilation-mode-line-errors
> +              (font-lock-ensure compilation-filter-start (point))

I worry that doing it there will slow down processing too much.
But even if we want to do it there, I think font-lock-ensure is wrong
because we shouldn't *highlight* (e.g. the user may prefer font-lock to
be disabled).

Does compilation--ensure-parse do what you want?

        Stefan