> It's precisely so that users could have their local versions loaded in
> preference to the bundled ones, I think.

But there are plenty of other ways to do that.   This makes it a little too
easy to override important core libraries, IMO.

realgud is just an example.  It uses names like js.el and info.el because
they are supposed to be loaded via `load-relative`, rather than required
directly, but subdirs.el placing them at the front of the load path is
what's causing trouble.  Rocky could add 'realgud-' to the beginning of
every elisp file in the application, but `load-relative` and the directory
structure makes that unnecessary.

You might argue that every elisp file in an application should be named to
avoid conflicts with core libraries, but the only reason I see for that
requirement is the current ordering of the load path.

And beyond the inconvenience caused by programs using `load-relative`, or
programs just accidentally using the same name as a core library, it seems
possible that a malicious developer could tuck their own `url.el` into an
otherwise innocuous package and cause some mayhem.

On Mon, Aug 1, 2016 at 9:39 AM, Eli Zaretskii <eliz@gnu.org> wrote:

> > From: Alex Dunn <dunn.alex@gmail.com>
> > Date: Mon, 1 Aug 2016 09:24:34 -0700
> >
> > Right now, `init_lread` in lread.c creates the initial load path by
> concatenating PATH_SITELOADSEARCH and
> > PATH_LOADSEARCH, in that order. Since subdirs.el searches recursively
> and adds everything to the
> > load-path, if I install (for example), realgud into site-lisp, things
> break because a number of Emacs' own
> > libraries are shadowed by realgud's language and utility modules:
> > - https://github.com/realgud/realgud/tree/master/realgud/common
> > - https://github.com/realgud/realgud/tree/master/realgud/lang
> >
> > Looking through the code history, this order has been deliberately
> maintained for well over a decade, but
> > what's the reason for letting core libraries be overridden like this?
>
> It's precisely so that users could have their local versions loaded in
> preference to the bundled ones, I think.
>
> If realgud somehow causes trouble due to this, the problem should be
> solved there, IMO.
>