bug#62734: Always fully rebuild autoloads in package-generate-autoloads

[Philip Kaludercic]

Leo Georg Gaskin <leo.gaskin@le0.gs> writes:

> Tags: patch
>
> Hello!
>
> I've been using the new package-vc.el functionality to great effect,
> but I have also come across a somewhat annoying bug.  If I use any of
> the provided commands to rebuild my local package while a autoloads
> file is already present, the newly generated autoloads file is
> consistently either incomplete or empty.
>
> The easiest way I've found to fix this is simply changing the
> `package-generate-autoloads' function to always rebuild the autoloads
> file by passing the relevant option to `loaddefs-generate'.  I think
> this change also makes sense on a larger scale, as package generation
> taking into account older build artifacts seems unintuitive.
>
> The attached patch implements this change.
>
> I've read that for small changes like this no copyright assignment
> is needed.  If I have misunderstood, please point me to the relevant
> documents so I can sign them.  Please also let me know if I have
> messed something up or you need any additional information.

It seems to me that your fix is the easiest way to tackle the issue,
without having to do a deep-dive into loaddefs.  Eli, can this be
applied to emacs-29?  An alternative fix would be to restrict the
changes to package-vc, but that seems like an unnecessary duplication,
since the change doesn't affect package.

> Best wishes
>
> Leo Gaskin
>
>
> In GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo
> version 1.16.0, Xaw3d scroll bars)
> Repository revision: 9848ae17161828190cc0ba31e89ae54a2f08a2ef
> Repository branch: master
> Windowing system distributor 'The X.Org Foundation', version 11.0.12101008
> System Description: NixOS 23.05 (Stoat)
>
> Configured using:
>  'configure
>  --prefix=/nix/store/y9bxk3kqk4isr28jcy1bclkdr5a4zd1v-emacs-git-20230407.0
>  --disable-build-details --with-modules --with-x-toolkit=lucid
>  --with-xft --with-cairo --with-native-compilation'