bug#77809: adding next-error support for flymake diagnostics buffers

[Eli Zaretskii]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Cc: 77809@debbugs.gnu.org,  Eli Zaretskii <eliz@gnu.org>
> Date: Tue, 22 Apr 2025 15:37:49 -0400
> 
> I think this is ready to be installed.  I went ahead and updated your
> commit message to include a changelog entry - please include that in
> future changes, see "Generating ChangeLog entries" in CONTRIBUTE.
> 
> Eli, can you please install the attached change?

See below.

> +(defvar-local flymake-current-diagnostic-line 0
> +  "The line of the most recently focused diagnostic in the flymake
> +diagnostics buffer.")

The first line of a doc string should be a single complete sentence.

> +(defun flymake--diagnostics-next-error (n &optional reset)
> +  "`next-error-function' for flymake diagnostics buffers.
> +N is an integer representing how many errors to move.
> +If RESET is non-nil, returns to the beginning of the errors before
                        ^^^^^^^
"return"

Thanks.