Might be. I can't test right now, but maybe Rudolf can. If it works then I'd say commit it.

João

On Fri, Oct 29, 2021, 14:35 Lars Ingebrigtsen <larsi@gnus.org> wrote:
Rudolf Adamkovič <salutis@me.com> writes:

> When checking a narrowed buffer with errors outside of the narrowed region, I get:
>
> ┌────
> │ error in process sentinel: flymake--highlight-line: Wrong type argument: integer-or-marker-p, nil
> │ error in process sentinel: Wrong type argument: integer-or-marker-p, nil
> └────
>
> Looks like `flymake-diag-region' returns `(nil . nil)' and `flymake-make-diagnostic' does not like that.

Perhaps this is the correct fix?  (João added to the CCs.)

diff --git a/doc/misc/flymake.texi b/doc/misc/flymake.texi
index 309bed7760..1d99342060 100644
--- a/doc/misc/flymake.texi
+++ b/doc/misc/flymake.texi
@@ -798,6 +798,7 @@ An annotated example backend
                        for type = (if (string-match "^warning" msg)
                                       :warning
                                     :error)
+                       when (and beg end)
                        collect (flymake-make-diagnostic source
                                                         beg
                                                         end


--
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   bloggy blog: http://lars.ingebrigtsen.no