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

[Eli Zaretskii <eliz@gnu.org>]

> From: Philip Kaludercic <philipk@posteo.net>
> Cc: leo.gaskin@le0.gs,  62734@debbugs.gnu.org
> Date: Sat, 29 Apr 2023 11:18:25 +0000
> 
> > "Building" is a strange term when we are talking about a Lisp package.
> 
> How come?  

There's nothing to "build".  Everything is already built.

> >> I think the central issue here is the
> >> 
> >>   (and (not defs) extra-data)
> >> 
> >> check.  Just because we did not find any new definitions to autoload
> >> /and/ EXTRA-DATA is non-nil, does not mean the old contents should be
> >> discarded.  The else-case already does the right thing, so I really do
> >> think that getting rid of the `if' could resolve the issue:
> >
> > What happens if a package has no autoloads?  The doc string says in
> > that case passing EXTRA-DATA will produce OUTPUT-FILE regardless.
> > Does your patch handle that?  (It's hard to tell, given all the
> > whitespace changes in the patch.)
> 
> It would, as the else-case of the if branch I am proposing to eliminate
> would still insert the EXTRA-DATA.

And if EXTRA-DATA is nil, then will we generate an empty OUTPUT file?