From bc2f8d064bad4da0325a09179b420f75c941ffd9 Mon Sep 17 00:00:00 2001
From: Artur Malabarba <bruce.connor.am@gmail.com>
Date: Mon, 12 Jan 2015 23:35:46 -0200
Subject: [PATCH] (package-install-from-buffer): Install packages from dired
 buffer.

---
 lisp/ChangeLog             |  1 +
 lisp/emacs-lisp/package.el | 39 ++++++++++++++++++++++++++++++++++-----
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index dce08a42255..13a87225bad 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -5,6 +5,7 @@
 	the pkg-desc, with desc-kind set to KIND.
 	(package-dir-info): New function. Find package information for a
 	directory. The return result is a `package-desc'.
+	(package-install-from-buffer): Install packages from dired buffer.
 
 2015-01-16  Jorgen Schaefer  <contact@jorgenschaefer.de>
 
diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index 77b15c104ef..78138e9ebcd 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -800,6 +800,20 @@ untar into a directory named DIR; otherwise, signal an error."
          (dirname (package-desc-full-name pkg-desc))
 	 (pkg-dir (expand-file-name dirname package-user-dir)))
     (pcase (package-desc-kind pkg-desc)
+      (`dir
+       (make-directory pkg-dir t)
+       (let ((file-list
+              (directory-files
+               default-directory 'full "\\`[^.].*\\.el\\'" 'nosort)))
+         (dolist (source-file file-list)
+           (let ((target-el-file
+                  (expand-file-name (file-name-nondirectory source-file) pkg-dir)))
+             (copy-file source-file target-el-file t)))
+         ;; Now that the files have been installed, this package is
+         ;; indistinguishable from a `tar' or a `single'. Let's make
+         ;; things simple by ensuring we're one of them.
+         (setf (package-desc-kind pkg-desc)
+               (if (> (length file-list) 1) 'tar 'single))))
       (`tar
        (make-directory package-user-dir t)
        ;; FIXME: should we delete PKG-DIR if it exists?
@@ -1318,13 +1332,28 @@ Return the pkg-desc, with desc-kind set to KIND."
 ;;;###autoload
 (defun package-install-from-buffer ()
   "Install a package from the current buffer.
-The current buffer is assumed to be a single .el or .tar file that follows the
-packaging guidelines; see info node `(elisp)Packaging'.
+The current buffer is assumed to be a single .el or .tar file or
+a directory.  These must follow the packaging guidelines (see
+info node `(elisp)Packaging').
+
+Specially, if current buffer is a directory, the -pkg.el
+description file is not mandatory, in which case the information
+is derived from the main .el file in the directory.
+
 Downloads and installs required packages as needed."
   (interactive)
-  (let ((pkg-desc (if (derived-mode-p 'tar-mode)
-                      (package-tar-file-info)
-                    (package-buffer-info))))
+  (let ((pkg-desc
+         (cond
+          ((derived-mode-p 'dired-mode)
+           ;; This is the only way a package-desc object with a `dir'
+           ;; desc-kind can be created.  Such packages can't be
+           ;; uploaded or installed from archives, they can only be
+           ;; installed from local buffers or directories.
+           (package-dir-info))
+          ((derived-mode-p 'tar-mode)
+           (package-tar-file-info))
+          (t
+           (package-buffer-info)))))
     ;; Download and install the dependencies.
     (let* ((requires (package-desc-reqs pkg-desc))
            (transaction (package-compute-transaction nil requires)))
-- 
2.11.4.GIT