Is package--list-loaded-files broken?

[Clément Pit-Claudel]

Hi all,

In the course of debugging proof-general's installation, I've run across the 
following bit in package--list-loaded-files:

           (mapcar
               (lambda (x) (let* ((file (file-relative-name x dir))
                             ;; Previously loaded file, if any.
                             (previous
                              (ignore-errors ;; ← !!
                                (file-name-sans-extension
                                 (file-truename (find-library-name file)))))
                             (pos (when previous (member previous history))))
                        ;; Return (RELATIVE-FILENAME . HISTORY-POSITION)
                        (when pos
                          (cons (file-name-sans-extension file) (length pos)))))
             (directory-files-recursively dir "\\`[^\\.].*\\.el\\'")))))

This is supposed to find all previously-loaded files in `dir'.  The part that 
I've highlighted with `;; ← !!' seems wrong: since package.el never loads 
`find-func' the function `find-library-name' is never defined, and calling it 
always raises an error, caught by the ignore-errors form.  This means that 
package--list-loaded-files always returns nil, and 
package--load-files-for-activation never reloads anything.

Of course, if the user's init file somehow requires find-func, or if any file 
compiled by package.el requires find-func, then find-library-name is available 
and package--list-loaded-files works just fine.

The reason why the missing function doesn't cause a byte-compiler warning is 
that package.el includes a (declare-function find-library-name "find-func" 
(library)) form.

Am I missing something?

Thanks!
Clément.