I am not sure what use case did you mean exactly.

(locate-library "tramp.el.gz" 'nosuffix)  will return the path to tramp.el.gz as expected

did you mean the following

(locate-library "tramp.el") returning the path to tramp.el.gz?


On Sun, May 11, 2014 at 10:46 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> From: Alex Kosorukoff <alex@3form.com>
> Date: Sun, 11 May 2014 10:38:39 -0700
> Cc: 17467@debbugs.gnu.org
>
> I think locate-library has an extra parameter nosuffix, so (locate-library
> "tramp.el" 'nosuffix) will find "tramp.el." I guess for backward
> compatibility we can set nosuffix to t whenever the name has a valid suffix
> already.

But what about adding ".gz" to it?

In any case, it is very convenient to not have to worry whether
there's already a suffix there.  You cannot always know that when user
input is involved.