bug#48269: 27.1: log-edit-generate-changelog-from-diff FAILURE

[Filipp Gunbin]

On 06/05/2021 19:23 -0400, Boruch Baum wrote:

> GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.24,
> cairo version 1.16.0) of 2021-03-27, modified by Debian
>
> ref: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=47784#45
>
> 1] Attempting to run function log-edit-generate-changelog-from-diff
>    returns an error message: 'Diff functionality has not been setup.'
>
> 2] The docstring for function log-edit-generate-changelog-from-diff
>    gives no indication how to set up 'diff functionality' or otherwise
>    guidance on how to use the function.
>
> 3] The source of the error message is function log-edit-show-diff. It,
>    too, lacks a useful docstring.
>
> 4] The code in function log-edit-show-diff indicates that the
>    configuration is performed via variable log-edit-diff-function.
>    However:
>
>    4.1] That variable lacks a docstring.
>
>    4.2] Setting it to a 'reasonable' value of 'ediff returns an error
>         (wrong-number-of-arguments (2 . 3) 0)

Give an emacs -Q recipe?