bug#66649: 29.1; `project-remember-projects-under' behavior doesn't match its doc

[Damien Cassou <damien@cassou.me>]

Hi,

the documentation of `project-remember-projects-under' is:

      "Index all projects below a directory DIR.  If RECURSIVE is
    non-nil, recurse into all subdirectories to find more projects.
    After finishing, a message is printed summarizing the progress.  The
    function returns the number of detected projects."

Regardless of the value of RECURSIVE, I understand from the above that
all child directories of the DIR argument will be investigated. The doc
doesn't say anything about investigating if DIR is itself a project or
not so I think it would make sense if the function wasn't.

But the code says otherwise (as far as I understand it):

(defun project-remember-projects-under (dir &optional recursive)
  (let ((queue (list dir)))
    ;; …
    (while queue
      (when-let ((subdir (pop queue))
                 ((file-directory-p subdir)))
        ;; maybe register `subdir' as a project
        ;; …
        (when (and recursive (file-directory-p subdir))
          (setq queue (nconc (directory-files subdir …) queue)))))))

The code above seems to investigate DIR first and, if RECURSIVE is
non-nil, look at the directories below it.

Also, the second check (file-directory-p subdir) seems unnecessary
because of the first one.

There is a part of the code I don't understand:

  (unless (eq recursive 'in-progress)

It seems nowhere in the code nor in the documentation do we say anything
about this 'in-progress special value. Is it a left over from a previous
(recursive) version of the algorithm?

Best

-- 
Damien Cassou

"Success is the ability to go from one failure to another without
losing enthusiasm." --Winston Churchill