Need help setting up redirects in /software/config

[Zack Weinberg]

Me and the maintainers of `config.sub` and `config.guess` (cc:ed) are
trying to set up some HTTP redirects so that when config.guess fails
it can print out a long-term stable URL for a newer version of itself,
instead of a URL that involves specifics of the VCS-to-web bridge for
the project, which have changed in the past and probably will again in
the future.  We've run into a problem and need some advice on how to
fix it.

In words, the redirects we want are:

https://www.gnu.org/software/config/config.guess
    -> concrete URL for the latest version of config.guess,
       currently https://git.savannah.gnu.org/cgit/config.git/plain/config.guess

https://www.gnu.org/software/config/config.sub
    -> concrete URL for the latest version of config.sub,
       currently https://git.savannah.gnu.org/cgit/config.git/plain/config.sub

https://www.gnu.org/software/config/
    -> https://savannah.gnu.org/projects/config

https://www.gnu.org/software/config/index.html
    -> https://savannah.gnu.org/projects/config

All other URLs beginning with https://www.gnu.org/software/config/
should return a 404 error.

We thought this .htaccess configuration would do what we want:

Redirect 307 /software/config/config.guess 
https://git.savannah.gnu.org/cgit/config.git/plain/config.guess
Redirect 307 /software/config/config.sub   
https://git.savannah.gnu.org/cgit/config.git/plain/config.sub
Redirect 307 /software/config/index.html   
https://savannah.gnu.org/projects/config
Redirect 307 /software/config/             
https://savannah.gnu.org/projects/config

But we found that this actually redirects *all* URLs beginning with
<https://www.gnu.org/software/config/> to
<https://savannah.gnu.org/projects/config>, including
<https://www.gnu.org/software/config/config.guess>,
<https://www.gnu.org/software/config/config.sub>, and
<https://www.gnu.org/software/config/nonexistent>.  Removing the last
line of the .htaccess (the one beginning "Redirect 307 /software/config/ ")
did not change the behavior.

Can you tell us what we need to put in .htaccess to get the redirects
we want?

Thanks,
zw