correct usage of package-upload-file for multi-file package?

Question

At my work (Windows 7), we don't have access to elpa or melpa, but we have a network drive which contains emacs packages that have been manually downloaded and approved.

Using code similar to the following (heavily based on https://emacs.stackexchange.com/a/17408/5142) Emacs users are able to have a MELPA-like experience.

(require 'package)
(setq myelpa-msde "//network/fsf/emacs-plugins/"
      myelpa (expand-file-name "myelpa/" user-emacs-directory)
      package-archives `(("myelpa" . ,myelpa))
      use-package-always-ensure t)
(package-initialize)
(unless (file-exists-p myelpa)
  (require 'package-x)
  (setq package-archive-upload-base myelpa)
  (mkdir myelpa)
  (dolist (file (directory-files myelpa-msde 'fqn "\\.*[.]\\(el\\|tar\\)"))
    (message "Preparing %s" file)
    (package-upload-file file)
    (when (string= (file-name-extension file) "tar")
      (copy-file file myelpa 'force)))
  (package-refresh-contents)
  (package-install 'use-package))
(require 'use-package)

However, look at that again

    (when (string= (file-name-extension file) "tar")
      (copy-file file myelpa 'force)))

without this hack, any tar file that gets uploaded to the "myelpa" local repository is corrupt (it seems to be a file containing just the directory listing of the original tar). The package index is updated correctly, so I was able to apply this workaround by just force copying the tarball again.

Is this a bug in Emacs or am I doing it wrong? According to https://www.gnu.org/software/emacs/manual/html_node/elisp/Package-Archives.html I would have thought this would be considered a "multi file package" and just work.

Answer 1

I've just run up against just this issue. It seems to me that what package-upload-file does is go to the buffer containing the tar file, set a string variable to the contents of the buffer by calling function buffer-substring-no-properties, then copy that string into your repository.

Trouble is, your tar-file buffer is in tar-mode, and so its contents are simply a listing of the items in the tar-file. And that listing is what gets copied, not the actual tar data. (My Emacs is version 24.5.1.)