Re: [PATCH] Re: package.el changes before the feature freeze

[Daniel Hackney <dan@haxney.org>]

Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>> The CL info pages refer to them as slots, so that's what I figured I'd
>> use.  There could be a better name for a package defstruct, but "field"
>> "property" and "attribute" are overdone :)
>
> Sure, use whatever suits you.
>
>> I agree that the slot name could definitely be improved. `name' does
>> imply a string to me, but I think that it is good for the "primary key"
>> of the alists to be a symbol. Something like `canonical-name' perhaps?
>> `id' maybe? I'm not terribly attached to any particular slot name.
>
> `name' is no worse than the others, so just use that.
>
>> This was intended to be related to `define-package'; it turns the
>> `define-package' call into a `package-desc' struct.
>
> I understand the motivation, but the use of a "package-" prefix is
> more important, I think.
>
>> I haven't looked at lexical binding in earnest. Should I reference
>> the non-prefixed form in the body of `define-package'?
>
> The symbols prefixed by "_" are not treated specially by the
> compiler/evaluator.  The use of _ only affects the warnings you might
> get (where a `_foo' that is used or a `foo' that is not used will signal
> a warning) and the way things are displayed in *Help* (where the
> underscore is stripped, since whether or not an argument is used is an
> implementation detail).

I replaced most of the instances of `concat' with `format' which means
that there is almost no use of `symbol-name' (since it is being done
within `format'). I also further standardized the naming of arguments;
NAME for the package name (as a symbol), SUMMARY for the one-line
description, and a couple others.

Everything uses the "package-*" prefix, and `define-package' has been
removed entirely. The "foo-pkg.el" files are no longer `load'ed
directly. Instead, they are read with `package-read-from-string' and the
cdr is sent to `package-desc-from-define', which has the same signature
as the old `package-define'.

Version 3 includes a basic test suite which exercises package
installing, both through lisp (`package-install-file') and through the
menu. Both single- and multi-file packages are covered, as is reading
from an "archive-contents" file. I haven't tested package deleting,
obsoleting, or upgrading, but, aside from name changes, I haven't done
much to disturb that part of the code. That would be the next big thing
I'd want to tackle.

Patch follows, with static version available here:

https://github.com/downloads/haxney/emacs/package-defstruct3.diff

Patch contents:

diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index 28d1662..602f6c8 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -169,6 +169,8 @@

 ;;; Code:

+(require 'cl-lib)
+
 (require 'tabulated-list)

 (defgroup package nil
@@ -244,11 +246,8 @@ Lower version numbers than this will probably be
understood as well.")
 ;; We don't prime the cache since it tends to get out of date.
 (defvar package-archive-contents nil
   "Cache of the contents of the Emacs Lisp Package Archive.
-This is an alist mapping package names (symbols) to package
-descriptor vectors.  These are like the vectors for `package-alist'
-but have extra entries: one which is 'tar for tar packages and
-'single for single-file packages, and one which is the name of
-the archive from which it came.")
+This is an alist mapping package names (symbols) to
+`package-desc' structures.")
 (put 'package-archive-contents 'risky-local-variable t)

 (defcustom package-user-dir (locate-user-emacs-file "elpa")
@@ -279,6 +278,50 @@ contrast, `package-user-dir' contains packages
for personal use."
   :group 'package
   :version "24.1")

+(cl-defstruct (package-desc
+	       ;; Rename the default constructor from `make-package-desc'.
+	       (:constructor package-desc-create)
+	       ;; Has the same interface as the old `define-package',
+	       ;; which is still used in the "foo-pkg.el" files. Extra
+	       ;; options can be supported by adding additional keys.
+	       (:constructor
+		package-desc-from-define
+		(name-string version-string &optional summary requirements
+			     &key kind archive
+			     &aux (name (intern name-string))
+			     (version (ignore-errors (version-to-list version-string)))
+			     (reqs (mapcar
+				    (lambda (elt)
+				      (list (car elt)
+					    (version-to-list (cadr elt))))
+				    requirements)))))
+	      "Structure containing information about an individual package.
+
+Slots:
+
+`name' Name of the package, as a symbol.
+
+`version' Version of the package, as a version list.
+
+`summary' Short description of the package, typically taken from
+the first line of the file.
+
+`reqs' Requirements of the package. A list of (PACKAGE
+VERSION-LIST) naming the dependent package and the minimum
+required version.
+
+`kind' The distribution format of the package. Currently, it is
+either `single' or `tar'.
+
+`archive' The name of the archive (as a string) whence this
+package came."
+	      name
+	      version
+	      (summary "No description available.")
+	      reqs
+	      kind
+	      archive)
+
 ;; The value is precomputed in finder-inf.el, but don't load that
 ;; until it's needed (i.e. when `package-initialize' is called).
 (defvar package--builtins nil
@@ -288,26 +331,13 @@ The actual value is initialized by loading the library
 function `package-built-in-p'.

 Each element has the form (PKG . DESC), where PKG is a package
-name (a symbol) and DESC is a vector that describes the package.
-The vector DESC has the form [VERSION-LIST REQS DOCSTRING].
-  VERSION-LIST is a version list.
-  REQS is a list of packages required by the package, each
-   requirement having the form (NAME VL), where NAME is a string
-   and VL is a version list.
-  DOCSTRING is a brief description of the package.")
+name (a symbol) and DESC is a `package-desc' structure.")
 (put 'package--builtins 'risky-local-variable t)

 (defvar package-alist nil
   "Alist of all packages available for activation.
 Each element has the form (PKG . DESC), where PKG is a package
-name (a symbol) and DESC is a vector that describes the package.
-
-The vector DESC has the form [VERSION-LIST REQS DOCSTRING].
-  VERSION-LIST is a version list.
-  REQS is a list of packages required by the package, each
-   requirement having the form (NAME VL) where NAME is a string
-   and VL is a version list.
-  DOCSTRING is a brief description of the package.
+name (a symbol) and DESC is a `package-desc' structure.

 This variable is set automatically by `package-load-descriptor',
 called via `package-initialize'.  To change which packages are
@@ -321,7 +351,10 @@ loaded and/or activated, customize `package-load-list'.")
 (defvar package-obsolete-alist nil
   "Representation of obsolete packages.
 Like `package-alist', but maps package name to a second alist.
-The inner alist is keyed by version.")
+The inner alist is keyed by version.
+
+Each element of the list is (NAME . VERSION-ALIST), where each
+entry in VERSION-ALIST is (VERSION-LIST . PACKAGE-DESC).")
 (put 'package-obsolete-alist 'risky-local-variable t)

 (defun package-version-join (vlist)
@@ -359,17 +392,50 @@ E.g., if given \"quux-23.0\", will return \"quux\""
   (if (string-match (concat "\\`" package-subdirectory-regexp "\\'") dirname)
       (match-string 1 dirname)))

-(defun package-load-descriptor (dir package)
-  "Load the description file in directory DIR for package PACKAGE.
-Here, PACKAGE is a string of the form NAME-VERSION, where NAME is
-the package name and VERSION is its version."
-  (let* ((pkg-dir (expand-file-name package dir))
+(defun package-load-descriptor (name version dir)
+  "Load the description file in directory DIR for package NAME.
+NAME is the package name as a symbol and VERSION must be a
+string."
+  (let* ((old-pkg (cdr-safe (assq name package-alist)))
+	 (pkg-dir (expand-file-name (format "%s-%s" name version) dir))
	 (pkg-file (expand-file-name
-		    (concat (package-strip-version package) "-pkg")
-		    pkg-dir)))
-    (when (and (file-directory-p pkg-dir)
-	       (file-exists-p (concat pkg-file ".el")))
-      (load pkg-file nil t))))
+		    (format "%s-pkg.el" name)
+		    pkg-dir))
+	 (pkg-def-contents (with-temp-buffer
+			     (insert-file-literally pkg-file)
+			     (buffer-string)))
+	 (pkg-def-parsed (package-read-from-string pkg-def-contents))
+	 pkg-desc)
+
+    (unless (eq (car pkg-def-parsed) 'define-package)
+      (error "No `define-package' sexp is present in `%s-pkg.el'" name))
+
+    (setq pkg-desc (apply #'package-desc-from-define
+			  (append (cdr pkg-def-parsed) '(:kind tar))))
+    (unless (equal (package-version-join (package-desc-version pkg-desc))
+		   version)
+      (error "Package has inconsistent versions"))
+    (unless (eq (package-desc-name pkg-desc) name)
+      (error "Package has inconsistent names"))
+
+    (cond
+     ;; If there's no old package, just add this to `package-alist'.
+     ((null old-pkg)
+      (push (cons name pkg-desc) package-alist))
+     ((version-list-< (package-desc-version old-pkg)
+		      (version-to-list version))
+      ;; Remove the old package and declare it obsolete.
+      (package-mark-obsolete old-pkg)
+      (cl-delete (package-desc-name old-pkg) package-alist :key 'car)
+      (push package-alist (cons name pkg-desc)))
+     ;; You can have two packages with the same version, e.g. one in
+     ;; the system package directory and one in your private
+     ;; directory.  We just let the first one win.
+     ((not (version-list-= (package-desc-version old-pkg)
+			   (version-to-list version)))
+      ;; The package is born obsolete.
+      (package-mark-obsolete pkg-desc)))
+    pkg-desc))

 (defun package-load-all-descriptors ()
   "Load descriptors for installed Emacs Lisp packages.
@@ -385,17 +451,17 @@ updates `package-alist' and `package-obsolete-alist'."
       (when (file-directory-p dir)
	(dolist (subdir (directory-files dir))
	  (when (string-match regexp subdir)
-	    (package-maybe-load-descriptor (match-string 1 subdir)
+	    (package-maybe-load-descriptor (intern (match-string 1 subdir))
					   (match-string 2 subdir)
					   dir)))))))

 (defun package-maybe-load-descriptor (name version dir)
   "Maybe load a specific package from directory DIR.
-NAME and VERSION are the package's name and version strings.
-This function checks `package-load-list', before actually loading
-the package by calling `package-load-descriptor'."
-  (let ((force (assq (intern name) package-load-list))
-	(subdir (concat name "-" version)))
+NAME is the package name as a symbol and VERSION is the package's
+version string. This function checks `package-load-list', before
+actually loading the package by calling`package-load-descriptor'."
+  (let ((force (assq name package-load-list))
+	(subdir (format "%s-%s" name version)))
     (and (file-directory-p (expand-file-name subdir dir))
	 ;; Check `package-load-list':
	 (cond ((null force)
@@ -410,28 +476,12 @@ the package by calling `package-load-descriptor'."
	       (t
		(error "Invalid element in `package-load-list'")))
	 ;; Actually load the descriptor:
-	 (package-load-descriptor dir subdir))))
-
-(defsubst package-desc-vers (desc)
-  "Extract version from a package description vector."
-  (aref desc 0))
-
-(defsubst package-desc-reqs (desc)
-  "Extract requirements from a package description vector."
-  (aref desc 1))
-
-(defsubst package-desc-doc (desc)
-  "Extract doc string from a package description vector."
-  (aref desc 2))
-
-(defsubst package-desc-kind (desc)
-  "Extract the kind of download from an archive package description vector."
-  (aref desc 3))
+	 (package-load-descriptor name version dir))))

 (defun package--dir (name version)
   "Return the directory where a package is installed, or nil if none.
-NAME and VERSION are both strings."
-  (let* ((subdir (concat name "-" version))
+NAME is the package name as a symbol and VERSION is a string."
+  (let* ((subdir (format "%s-%s" name version))
	 (dir-list (cons package-user-dir package-directory-list))
	 pkg-dir)
     (while dir-list
@@ -442,9 +492,9 @@ NAME and VERSION are both strings."
	  (setq dir-list (cdr dir-list)))))
     pkg-dir))

-(defun package-activate-1 (package pkg-vec)
-  (let* ((name (symbol-name package))
-	 (version-str (package-version-join (package-desc-vers pkg-vec)))
+(defun package-activate-1 (pkg-desc)
+  (let* ((name (package-desc-name pkg-desc))
+	 (version-str (package-version-join (package-desc-version pkg-desc)))
	 (pkg-dir (package--dir name version-str)))
     (unless pkg-dir
       (error "Internal error: unable to find directory for `%s-%s'"
@@ -457,8 +507,8 @@ NAME and VERSION are both strings."
       (push pkg-dir Info-directory-list))
     ;; Add to load path, add autoloads, and activate the package.
     (push pkg-dir load-path)
-    (load (expand-file-name (concat name "-autoloads") pkg-dir) nil t)
-    (push package package-activated-list)
+    (load (expand-file-name (format "%s-autoloads" name) pkg-dir) nil t)
+    (push name package-activated-list)
     ;; Don't return nil.
     t))

@@ -471,98 +521,58 @@ specifying the minimum acceptable version."
       (version-list-<= min-version (version-to-list emacs-version))
     (let ((elt (assq package package--builtins)))
       (and elt (version-list-<= min-version
-				(package-desc-vers (cdr elt)))))))
+				(package-desc-version (cdr elt)))))))

 ;; This function goes ahead and activates a newer version of a package
 ;; if an older one was already activated.  This is not ideal; we'd at
 ;; least need to check to see if the package has actually been loaded,
 ;; and not merely activated.
-(defun package-activate (package min-version)
-  "Activate package PACKAGE, of version MIN-VERSION or newer.
+(defun package-activate (name min-version)
+  "Activate package NAME, of version MIN-VERSION or newer.
 MIN-VERSION should be a version list.
-If PACKAGE has any dependencies, recursively activate them.
+If NAME has any dependencies, recursively activate them.
 Return nil if the package could not be activated."
-  (let ((pkg-vec (cdr (assq package package-alist)))
+  (let ((pkg-desc (cdr (assq name package-alist)))
	available-version found)
     ;; Check if PACKAGE is available in `package-alist'.
-    (when pkg-vec
-      (setq available-version (package-desc-vers pkg-vec)
+    (when pkg-desc
+      (setq available-version (package-desc-version pkg-desc)
	    found (version-list-<= min-version available-version)))
     (cond
      ;; If no such package is found, maybe it's built-in.
      ((null found)
-      (package-built-in-p package min-version))
+      (package-built-in-p name min-version))
      ;; If the package is already activated, just return t.
-     ((memq package package-activated-list)
+     ((memq name package-activated-list)
       t)
      ;; Otherwise, proceed with activation.
      (t
       (let ((fail (catch 'dep-failure
		    ;; Activate its dependencies recursively.
-		    (dolist (req (package-desc-reqs pkg-vec))
+		    (dolist (req (package-desc-reqs pkg-desc))
		      (unless (package-activate (car req) (cadr req))
			(throw 'dep-failure req))))))
	(if fail
	    (warn "Unable to activate package `%s'.
 Required package `%s-%s' is unavailable"
-		  package (car fail) (package-version-join (cadr fail)))
+		  name (car fail) (package-version-join (cadr fail)))
	  ;; If all goes well, activate the package itself.
-	  (package-activate-1 package pkg-vec)))))))
+	  (package-activate-1 pkg-desc)))))))

-(defun package-mark-obsolete (package pkg-vec)
-  "Put package on the obsolete list, if not already there."
-  (let ((elt (assq package package-obsolete-alist)))
-    (if elt
-	;; If this obsolete version does not exist in the list, update
-	;; it the list.
-	(unless (assoc (package-desc-vers pkg-vec) (cdr elt))
-	  (setcdr elt (cons (cons (package-desc-vers pkg-vec) pkg-vec)
-			    (cdr elt))))
+(defun package-mark-obsolete (pkg-desc)
+  "Put PKG-DESC on the obsolete list, if not already there."
+  (let* ((name (package-desc-name pkg-desc))
+	 (existing-elt (assq name package-obsolete-alist))
+	 (pkg-version (package-desc-version pkg-desc)))
+    (if existing-elt
+	;; Add this obsolete version to the list if it is not already there.
+	(unless (assoc pkg-version (cdr existing-elt))
+	  (setcdr existing-elt (cons (cons pkg-version pkg-desc)
+				     (cdr existing-elt))))
       ;; Make a new association.
-      (push (cons package (list (cons (package-desc-vers pkg-vec)
-				      pkg-vec)))
+      (push (cons name (list (cons pkg-version pkg-desc)))
	    package-obsolete-alist))))

-(defun define-package (name-string version-string
-				&optional docstring requirements
-				&rest _extra-properties)
-  "Define a new package.
-NAME-STRING is the name of the package, as a string.
-VERSION-STRING is the version of the package, as a string.
-DOCSTRING is a short description of the package, a string.
-REQUIREMENTS is a list of dependencies on other packages.
- Each requirement is of the form (OTHER-PACKAGE OTHER-VERSION),
- where OTHER-VERSION is a string.
-
-EXTRA-PROPERTIES is currently unused."
-  (let* ((name (intern name-string))
-	 (version (version-to-list version-string))
-	 (new-pkg-desc
-	  (cons name
-		(vector version
-			(mapcar
-			 (lambda (elt)
-			   (list (car elt)
-				 (version-to-list (car (cdr elt)))))
-			 requirements)
-			docstring)))
-	 (old-pkg (assq name package-alist)))
-    (cond
-     ;; If there's no old package, just add this to `package-alist'.
-     ((null old-pkg)
-      (push new-pkg-desc package-alist))
-     ((version-list-< (package-desc-vers (cdr old-pkg)) version)
-      ;; Remove the old package and declare it obsolete.
-      (package-mark-obsolete name (cdr old-pkg))
-      (setq package-alist (cons new-pkg-desc
-				(delq old-pkg package-alist))))
-     ;; You can have two packages with the same version, e.g. one in
-     ;; the system package directory and one in your private
-     ;; directory.  We just let the first one win.
-     ((not (version-list-= (package-desc-vers (cdr old-pkg)) version))
-      ;; The package is born obsolete.
-      (package-mark-obsolete name (cdr new-pkg-desc))))))
-
 ;; From Emacs 22.
 (defun package-autoload-ensure-default-file (file)
   "Make sure that the autoload file FILE exists and if not create it."
@@ -584,13 +594,13 @@ EXTRA-PROPERTIES is currently unused."

 (defun package-generate-autoloads (name pkg-dir)
   (require 'autoload)         ;Load before we let-bind generated-autoload-file!
-  (let* ((auto-name (concat name "-autoloads.el"))
-	 ;;(ignore-name (concat name "-pkg.el"))
+  (let* ((auto-name (format "%s-autoloads.el" name))
	 (generated-autoload-file (expand-file-name auto-name pkg-dir))
	 (version-control 'never))
     (unless (fboundp 'autoload-ensure-default-file)
       (package-autoload-ensure-default-file generated-autoload-file))
-    (update-directory-autoloads pkg-dir)))
+    (update-directory-autoloads pkg-dir)
+    (kill-buffer (get-buffer auto-name))))

 (defvar tar-parse-info)
 (declare-function tar-untar-buffer "tar-mode" ())
@@ -608,9 +618,10 @@ untar into a directory named DIR; otherwise,
signal an error."
	(error "Package does not untar cleanly into directory %s/" dir))))
   (tar-untar-buffer))

-(defun package-unpack (package version)
-  (let* ((name (symbol-name package))
-	 (dirname (concat name "-" version))
+(defun package-unpack (name version)
+  "Unpack a tar package.
+VERSION must be a string. NAME is the package name as a symbol."
+  (let* ((dirname (format "%s-%s" name version))
	 (pkg-dir (expand-file-name dirname package-user-dir)))
     (make-directory package-user-dir t)
     ;; FIXME: should we delete PKG-DIR if it exists?
@@ -620,30 +631,33 @@ untar into a directory named DIR; otherwise,
signal an error."

 (defun package--make-autoloads-and-compile (name pkg-dir)
   "Generate autoloads and do byte-compilation for package named NAME.
-PKG-DIR is the name of the package directory."
+NAME is the name of the file to compile as a symbol and PKG-DIR
+is the name of the package directory."
   (package-generate-autoloads name pkg-dir)
   (let ((load-path (cons pkg-dir load-path)))
     ;; We must load the autoloads file before byte compiling, in
     ;; case there are magic cookies to set up non-trivial paths.
-    (load (expand-file-name (concat name "-autoloads") pkg-dir) nil t)
+    (load (expand-file-name (format "%s-autoloads" name) pkg-dir) nil t)
     (byte-recompile-directory pkg-dir 0 t)))

 (defun package--write-file-no-coding (file-name)
   (let ((buffer-file-coding-system 'no-conversion))
     (write-region (point-min) (point-max) file-name)))

-(defun package-unpack-single (file-name version desc requires)
-  "Install the contents of the current buffer as a package."
+(defun package-unpack-single (name version desc requires)
+  "Install the contents of the current buffer as a package.
+NAME is the name of the package as a symbol; VERSION and DESC
+must be strings."
   ;; Special case "package".
-  (if (string= file-name "package")
+  (if (eq name 'package)
       (package--write-file-no-coding
-       (expand-file-name (concat file-name ".el") package-user-dir))
-    (let* ((pkg-dir  (expand-file-name (concat file-name "-"
+       (expand-file-name (format "%s.el" name) package-user-dir))
+    (let* ((pkg-dir (expand-file-name (format  "%s-%s" name
					       (package-version-join
						(version-to-list version)))
-				       package-user-dir))
-	   (el-file  (expand-file-name (concat file-name ".el") pkg-dir))
-	   (pkg-file (expand-file-name (concat file-name "-pkg.el") pkg-dir)))
+				      package-user-dir))
+	   (el-file  (expand-file-name (format "%s.el" name) pkg-dir))
+	   (pkg-file (expand-file-name (format "%s-pkg.el" name) pkg-dir)))
       (make-directory pkg-dir t)
       (package--write-file-no-coding el-file)
       (let ((print-level nil)
@@ -652,21 +666,20 @@ PKG-DIR is the name of the package directory."
	 (concat
	  (prin1-to-string
	   (list 'define-package
-		 file-name
+		 (symbol-name name)
		 version
		 desc
-		 (list 'quote
-		       ;; Turn version lists into string form.
-		       (mapcar
-			(lambda (elt)
-			  (list (car elt)
-				(package-version-join (cadr elt))))
-			requires))))
+		 ;; Turn version lists into string form.
+		 (mapcar
+		  (lambda (elt)
+		    (list (car elt)
+			  (package-version-join (cadr elt))))
+		  requires)))
	  "\n")
	 nil
	 pkg-file
	 nil nil nil 'excl))
-      (package--make-autoloads-and-compile file-name pkg-dir))))
+      (package--make-autoloads-and-compile name pkg-dir))))

 (defmacro package--with-work-buffer (location file &rest body)
   "Run BODY in a buffer containing the contents of FILE at LOCATION.
@@ -714,26 +727,26 @@ It will move point to somewhere in the headers."
 (defun package-download-single (name version desc requires)
   "Download and install a single-file package."
   (let ((location (package-archive-base name))
-	(file (concat (symbol-name name) "-" version ".el")))
+	(file (format "%s-%s.el" name version)))
     (package--with-work-buffer location file
-      (package-unpack-single (symbol-name name) version desc requires))))
+			       (package-unpack-single name version desc requires))))

 (defun package-download-tar (name version)
   "Download and install a tar package."
   (let ((location (package-archive-base name))
-	(file (concat (symbol-name name) "-" version ".tar")))
+	(file (format "%s-%s.tar" name version)))
     (package--with-work-buffer location file
-      (package-unpack name version))))
+			       (package-unpack name version))))

-(defun package-installed-p (package &optional min-version)
-  "Return true if PACKAGE, of MIN-VERSION or newer, is installed.
-MIN-VERSION should be a version list."
-  (let ((pkg-desc (assq package package-alist)))
+(defun package-installed-p (name &optional min-version)
+  "Return true if NAME, of MIN-VERSION or newer, is installed.
+NAME must be a symbol and MIN-VERSION must be a version list."
+  (let ((pkg-desc (assq name package-alist)))
     (if pkg-desc
	(version-list-<= min-version
-			 (package-desc-vers (cdr pkg-desc)))
+			 (package-desc-version (cdr pkg-desc)))
       ;; Also check built-in packages.
-      (package-built-in-p package min-version))))
+      (package-built-in-p name min-version))))

 (defun package-compute-transaction (package-list requirements)
   "Return a list of packages to be installed, including PACKAGE-LIST.
@@ -754,7 +767,7 @@ not included in this list."
       (unless (package-installed-p next-pkg next-version)
	;; A package is required, but not installed.  It might also be
	;; blocked via `package-load-list'.
-	(let ((pkg-desc (assq next-pkg package-archive-contents))
+	(let ((pkg-desc (cdr (assq next-pkg package-archive-contents)))
	      hold)
	  (when (setq hold (assq next-pkg package-load-list))
	    (setq hold (cadr hold))
@@ -774,18 +787,18 @@ but version %s required"
		   (symbol-name next-pkg)
		   (package-version-join next-version)))
	  (unless (version-list-<= next-version
-				   (package-desc-vers (cdr pkg-desc)))
+				   (package-desc-version pkg-desc))
	    (error
	     "Need package `%s-%s', but only %s is available"
	     (symbol-name next-pkg) (package-version-join next-version)
-	     (package-version-join (package-desc-vers (cdr pkg-desc)))))
+	     (package-version-join (package-desc-version pkg-desc))))
	  ;; Only add to the transaction if we don't already have it.
	  (unless (memq next-pkg package-list)
	    (push next-pkg package-list))
	  (setq package-list
		(package-compute-transaction package-list
					     (package-desc-reqs
-					      (cdr pkg-desc))))))))
+					      pkg-desc)))))))
   package-list)

 (defun package-read-from-string (str)
@@ -828,8 +841,6 @@ If successful, set `package-archive-contents'."
   "Re-read archive contents for ARCHIVE.
 If successful, set the variable `package-archive-contents'.
 If the archive version is too new, signal an error."
-  ;; Version 1 of 'archive-contents' is identical to our internal
-  ;; representation.
   (let* ((dir (concat "archives/" archive))
	 (contents-file (concat dir "/archive-contents"))
	 contents)
@@ -839,16 +850,24 @@ If the archive version is too new, signal an error."

 (defun package--add-to-archive-contents (package archive)
   "Add the PACKAGE from the given ARCHIVE if necessary.
-Also, add the originating archive to the end of the package vector."
-  (let* ((name    (car package))
-         (version (package-desc-vers (cdr package)))
-         (entry   (cons name
-			(vconcat (cdr package) (vector archive))))
-         (existing-package (assq name package-archive-contents)))
+Also, add the originating archive to the `package-desc' structure."
+  (let* ((name (car package))
+	 (pkg-desc
+	  ;; These are the offsets into the "archive-contents"
+	  ;; array. They are formatted this way for historical reasons
+	  ;; which is why they are magic numbers here.
+	  (package-desc-create :name name
+			       :version (aref (cdr package) 0)
+			       :reqs (aref (cdr package) 1)
+			       :summary (aref (cdr package) 2)
+			       :kind (aref (cdr package) 3)
+			       :archive archive))
+	 (entry (cons name pkg-desc))
+	 (existing-package (assq name package-archive-contents)))
     (cond ((not existing-package)
	   (add-to-list 'package-archive-contents entry))
-	  ((version-list-< (package-desc-vers (cdr existing-package))
-			   version)
+	  ((version-list-< (package-desc-version (cdr existing-package))
+			   (package-desc-version pkg-desc))
	   ;; Replace the entry with this one.
	   (setq package-archive-contents
		 (cons entry
@@ -867,21 +886,21 @@ using `package-compute-transaction'."
	   ;; `package-load-list', download the held version.
	   (hold (cadr (assq elt package-load-list)))
	   (v-string (or (and (stringp hold) hold)
-			 (package-version-join (package-desc-vers desc))))
+			 (package-version-join (package-desc-version desc))))
	   (kind (package-desc-kind desc)))
       (cond
	((eq kind 'tar)
	(package-download-tar elt v-string))
	((eq kind 'single)
	(package-download-single elt v-string
-				 (package-desc-doc desc)
+				 (package-desc-summary desc)
				 (package-desc-reqs desc)))
	(t
	(error "Unknown package kind: %s" (symbol-name kind))))
       ;; If package A depends on package B, then A may `require' B
       ;; during byte compilation.  So we need to activate B before
       ;; unpacking A.
-      (package-maybe-load-descriptor (symbol-name elt) v-string
+      (package-maybe-load-descriptor elt v-string
				     package-user-dir)
       (package-activate elt (version-to-list v-string)))))

@@ -928,17 +947,7 @@ Otherwise return nil."
       (error nil))))

 (defun package-buffer-info ()
-  "Return a vector describing the package in the current buffer.
-The vector has the form
-
-   [FILENAME REQUIRES DESCRIPTION VERSION COMMENTARY]
-
-FILENAME is the file name, a string, sans the \".el\" extension.
-REQUIRES is a list of requirements, each requirement having the
- form (NAME VER); NAME is a string and VER is a version list.
-DESCRIPTION is the package description, a string.
-VERSION is the version, a string.
-COMMENTARY is the commentary section, a string, or nil if none.
+  "Return a `package-desc' for the package in the current buffer.

 If the buffer does not contain a conforming package, signal an
 error.  If there is a package, narrow the buffer to the file's
@@ -947,9 +956,9 @@ boundaries."
   (unless (re-search-forward "^;;; \\([^ ]*\\)\\.el ---[
\t]*\\(.*?\\)[ \t]*\\(-\\*-.*-\\*-[ \t]*\\)?$" nil t)
     (error "Packages lacks a file header"))
   (let ((file-name (match-string-no-properties 1))
-	(desc      (match-string-no-properties 2))
+	(summary   (match-string-no-properties 2))
	(start     (line-beginning-position)))
-    (unless (search-forward (concat ";;; " file-name ".el ends here"))
+    (unless (search-forward (format ";;; %s.el ends here"  file-name))
       (error "Package lacks a terminating comment"))
     ;; Try to include a trailing newline.
     (forward-line)
@@ -968,19 +977,17 @@ boundaries."
       (unless pkg-version
	(error
	 "Package lacks a \"Version\" or \"Package-Version\" header"))
-      ;; Turn string version numbers into list form.
-      (setq requires
-	    (mapcar
-	     (lambda (elt)
-	       (list (car elt)
-		     (version-to-list (car (cdr elt)))))
-	     requires))
-      (vector file-name requires desc pkg-version commentary))))
+
+      (package-desc-create :name (intern file-name)
+			   :version (version-to-list pkg-version)
+			   :summary summary
+			   :reqs requires
+			   :kind 'single))))

 (defun package-tar-file-info (file)
-  "Find package information for a tar file.
-FILE is the name of the tar file to examine.
-The return result is a vector like `package-buffer-info'."
+  "Build a `package-desc' from the contents of a tar file.
+Looks for a \"foo-pkg.el\" file in the tar file which must
+contain a package definition."
   (let ((default-directory (file-name-directory file))
	(file (file-name-nondirectory file)))
     (unless (string-match (concat "\\`" package-subdirectory-regexp
"\\.tar\\'")
@@ -991,68 +998,52 @@ The return result is a vector like `package-buffer-info'."
	   ;; Extract the package descriptor.
	   (pkg-def-contents (shell-command-to-string
			      ;; Requires GNU tar.
-			      (concat "tar -xOf " file " "
-
-				      pkg-name "-" pkg-version "/"
-				      pkg-name "-pkg.el")))
+			      (format "tar -xOf %s %s-%s/%s-pkg.el"
+				      file pkg-name pkg-version pkg-name)))
	   (pkg-def-parsed (package-read-from-string pkg-def-contents)))
       (unless (eq (car pkg-def-parsed) 'define-package)
	(error "No `define-package' sexp is present in `%s-pkg.el'" pkg-name))
-      (let ((name-str       (nth 1 pkg-def-parsed))
-	    (version-string (nth 2 pkg-def-parsed))
-	    (docstring      (nth 3 pkg-def-parsed))
-	    (requires       (nth 4 pkg-def-parsed))
-	    (readme (shell-command-to-string
-		     ;; Requires GNU tar.
-		     (concat "tar -xOf " file " "
-			     pkg-name "-" pkg-version "/README"))))
-	(unless (equal pkg-version version-string)
+
+      (let ((pkg-desc (apply #'package-desc-from-define
+			     (append (cdr pkg-def-parsed) '(:kind tar)))))
+	(unless (equal (package-version-join (package-desc-version pkg-desc))
+		       pkg-version)
	  (error "Package has inconsistent versions"))
-	(unless (equal pkg-name name-str)
+	(unless (equal (symbol-name (package-desc-name pkg-desc))
+		       pkg-name)
	  (error "Package has inconsistent names"))
-	;; Kind of a hack.
-	(if (string-match ": Not found in archive" readme)
-	    (setq readme nil))
-	;; Turn string version numbers into list form.
-	(if (eq (car requires) 'quote)
-	    (setq requires (car (cdr requires))))
-	(setq requires
-	      (mapcar (lambda (elt)
-			(list (car elt)
-			      (version-to-list (cadr elt))))
-		      requires))
-	(vector pkg-name requires docstring version-string readme)))))
+
+	pkg-desc))))

 ;;;###autoload
-(defun package-install-from-buffer (pkg-info type)
+(defun package-install-from-buffer (pkg-desc)
   "Install a package from the current buffer.
 When called interactively, the current buffer is assumed to be a
 single .el file that follows the packaging guidelines; see info
 node `(elisp)Packaging'.

-When called from Lisp, PKG-INFO is a vector describing the
-information, of the type returned by `package-buffer-info'; and
-TYPE is the package type (either `single' or `tar')."
-  (interactive (list (package-buffer-info) 'single))
+When called from Lisp, PKG-DESC is a `package-desc' structure."
+  (interactive (list (package-buffer-info)))
   (save-excursion
     (save-restriction
-      (let* ((file-name (aref pkg-info 0))
-	     (requires  (aref pkg-info 1))
-	     (desc (if (string= (aref pkg-info 2) "")
-		       "No description available."
-		     (aref pkg-info 2)))
-	     (pkg-version (aref pkg-info 3)))
+      (let* ((name (package-desc-name pkg-desc))
+	     (requires (package-desc-reqs pkg-desc))
+	     (pkg-version (package-desc-version pkg-desc))
+	     (kind (package-desc-kind pkg-desc)))
	;; Download and install the dependencies.
	(let ((transaction (package-compute-transaction nil requires)))
	  (package-download-transaction transaction))
	;; Install the package itself.
	(cond
-	 ((eq type 'single)
-	  (package-unpack-single file-name pkg-version desc requires))
-	 ((eq type 'tar)
-	  (package-unpack (intern file-name) pkg-version))
+	 ((eq kind 'single)
+	  (package-unpack-single name
+				 (package-version-join pkg-version)
+				 (package-desc-summary pkg-desc)
+				 requires))
+	 ((eq kind 'tar)
+	  (package-unpack name (package-version-join pkg-version)))
	 (t
-	  (error "Unknown type: %s" (symbol-name type))))
+	  (error "Unknown package type: %s" kind)))
	;; Try to activate it.
	(package-initialize)))))

@@ -1065,9 +1056,9 @@ The file can either be a tar file or an Emacs Lisp file."
     (insert-file-contents-literally file)
     (cond
      ((string-match "\\.el$" file)
-      (package-install-from-buffer (package-buffer-info) 'single))
+      (package-install-from-buffer (package-buffer-info)))
      ((string-match "\\.tar$" file)
-      (package-install-from-buffer (package-tar-file-info file) 'tar))
+      (package-install-from-buffer (package-tar-file-info file)))
      (t (error "Unrecognized extension `%s'" (file-name-extension file))))))

 (defun package-delete (name version)
@@ -1083,9 +1074,10 @@ The file can either be a tar file or an Emacs Lisp file."
	     name version))))

 (defun package-archive-base (name)
-  "Return the archive containing the package NAME."
-  (let ((desc (cdr (assq (intern-soft name) package-archive-contents))))
-    (cdr (assoc (aref desc (- (length desc) 1)) package-archives))))
+  "Return the archive containing the package NAME.
+NAME must be a symbol."
+  (let ((desc (cdr (assq name package-archive-contents))))
+    (cdr (assoc (package-desc-archive desc) package-archives))))

 (defun package--download-one-archive (archive file)
   "Retrieve an archive file FILE from ARCHIVE, and cache it.
@@ -1130,7 +1122,7 @@ If optional arg NO-ACTIVATE is non-nil, don't
activate packages."
   (package-read-all-archive-contents)
   (unless no-activate
     (dolist (elt package-alist)
-      (package-activate (car elt) (package-desc-vers (cdr elt)))))
+      (package-activate (car elt) (package-desc-version (cdr elt)))))
   (setq package--initialized t))

 \f
@@ -1177,21 +1169,21 @@ If optional arg NO-ACTIVATE is non-nil, don't
activate packages."
     (cond
      ;; Loaded packages are in `package-alist'.
      ((setq desc (cdr (assq package package-alist)))
-      (setq version (package-version-join (package-desc-vers desc)))
+      (setq version (package-version-join (package-desc-version desc)))
       (if (setq pkg-dir (package--dir package-name version))
	  (insert "an installed package.\n\n")
	;; This normally does not happen.
	(insert "a deleted package.\n\n")))
      ;; Available packages are in `package-archive-contents'.
      ((setq desc (cdr (assq package package-archive-contents)))
-      (setq version (package-version-join (package-desc-vers desc))
+      (setq version (package-version-join (package-desc-version desc))
	    installable t)
       (if built-in
	  (insert "a built-in package.\n\n")
	(insert "an uninstalled package.\n\n")))
      (built-in
       (setq desc (cdr built-in)
-	    version (package-version-join (package-desc-vers desc)))
+	    version (package-version-join (package-desc-version desc)))
       (insert "a built-in package.\n\n"))
      (t
       (insert "an orphan package.\n\n")))
@@ -1240,7 +1232,7 @@ If optional arg NO-ACTIVATE is non-nil, don't
activate packages."
	(dolist (req reqs)
	  (setq name (car req)
		vers (cadr req)
-		text (format "%s-%s" (symbol-name name)
+		text (format "%s-%s" name
			     (package-version-join vers)))
	  (cond (first (setq first nil))
		((>= (+ 2 (current-column) (length text))
@@ -1250,11 +1242,11 @@ If optional arg NO-ACTIVATE is non-nil, don't
activate packages."
	  (help-insert-xref-button text 'help-package name))
	(insert "\n")))
     (insert "    " (propertize "Summary" 'font-lock-face 'bold)
-	    ": " (if desc (package-desc-doc desc)) "\n\n")
+	    ": " (if desc (package-desc-summary desc)) "\n\n")

     (if built-in
	;; For built-in packages, insert the commentary.
-	(let ((fn (locate-file (concat package-name ".el") load-path
+	(let ((fn (locate-file (format "%s.el" package-name) load-path
			       load-file-rep-suffixes))
	      (opoint (point)))
	  (insert (or (lm-commentary fn) ""))
@@ -1264,14 +1256,14 @@ If optional arg NO-ACTIVATE is non-nil, don't
activate packages."
	      (replace-match ""))
	    (while (re-search-forward "^\\(;+ ?\\)" nil t)
	      (replace-match ""))))
-      (let ((readme (expand-file-name (concat package-name "-readme.txt")
+      (let ((readme (expand-file-name (format "%s-readme.txt" package-name)
				      package-user-dir))
	    readme-string)
	;; For elpa packages, try downloading the commentary.  If that
	;; fails, try an existing readme file in `package-user-dir'.
	(cond ((condition-case nil
		   (package--with-work-buffer (package-archive-base package)
-					      (concat package-name "-readme.txt")
+					      (format "%s-readme.txt" package-name)
		     (setq buffer-file-name
			   (expand-file-name readme package-user-dir))
		     (let ((version-control 'never))
@@ -1376,29 +1368,38 @@ Letters do not insert themselves; instead,
they are commands.
   (setq tabulated-list-sort-key (cons "Status" nil))
   (tabulated-list-init-header))

-(defmacro package--push (package desc status listname)
+(defmacro package--push (pkg status listname)
   "Convenience macro for `package-menu--generate'.
-If the alist stored in the symbol LISTNAME lacks an entry for a
-package PACKAGE with descriptor DESC, add one.  The alist is
-keyed with cons cells (PACKAGE . VERSION-LIST), where PACKAGE is
-a symbol and VERSION-LIST is a version list."
-  `(let* ((version (package-desc-vers ,desc))
-	  (key (cons ,package version)))
-     (unless (assoc key ,listname)
-       (push (list key ,status (package-desc-doc ,desc)) ,listname))))
+If the alist stored in the symbol LISTNAME lacks an entry for
+`package-desc' PKG, add one.  The alist is keyed with cons
+cells (NAME . VERSION-LIST), where NAME is a symbol and
+VERSION-LIST is a version list. The values of LISTNAME are lists
+of STATUS and the package summary.
+
+LISTNAME looks like this:
+
+\( ((foo . (1 2 3))
+    (status summary)) ... )"
+  `(cl-pushnew (list (cons (package-desc-name ,pkg)
+			   (package-desc-version ,pkg))
+		     ,status
+		     (package-desc-summary ,pkg))
+	       ,listname
+	       :key 'car
+	       :test 'equal))

 (defun package-menu--generate (remember-pos packages)
   "Populate the Package Menu.
 If REMEMBER-POS is non-nil, keep point on the same entry.
 PACKAGES should be t, which means to display all known packages,
 or a list of package names (symbols) to display."
-  ;; Construct list of ((PACKAGE . VERSION) STATUS DESCRIPTION).
-  (let (info-list name)
+  ;; Construct list of ((NAME . VERSION-LIST) STATUS DESCRIPTION)
+  (let (info-list name builtin)
     ;; Installed packages:
     (dolist (elt package-alist)
       (setq name (car elt))
       (when (or (eq packages t) (memq name packages))
-	(package--push name (cdr elt)
+	(package--push (cdr elt)
		       (if (stringp (cadr (assq name package-load-list)))
			   "held" "installed")
		       info-list)))
@@ -1408,14 +1409,14 @@ or a list of package names (symbols) to display."
       (setq name (car elt))
       (when (and (not (eq name 'emacs)) ; Hide the `emacs' package.
		 (or (eq packages t) (memq name packages)))
-	(package--push name (cdr elt) "built-in" info-list)))
+	(package--push (cdr elt) "built-in" info-list)))

     ;; Available and disabled packages:
     (dolist (elt package-archive-contents)
       (setq name (car elt))
       (when (or (eq packages t) (memq name packages))
	(let ((hold (assq name package-load-list)))
-	  (package--push name (cdr elt)
+	  (package--push (cdr elt)
			 (cond
			  ((and hold (null (cadr hold))) "disabled")
			  ((memq name package-menu--new-package-list) "new")
@@ -1426,21 +1427,21 @@ or a list of package names (symbols) to display."
     (dolist (elt package-obsolete-alist)
       (dolist (inner-elt (cdr elt))
	(when (or (eq packages t) (memq (car elt) packages))
-	  (package--push (car elt) (cdr inner-elt) "obsolete" info-list))))
+	  (package--push (cdr inner-elt) "obsolete" info-list))))

     ;; Print the result.
     (setq tabulated-list-entries (mapcar 'package-menu--print-info info-list))
     (tabulated-list-print remember-pos)))

-(defun package-menu--print-info (pkg)
+(defun package-menu--print-info (entry)
   "Return a package entry suitable for `tabulated-list-entries'.
-PKG has the form ((PACKAGE . VERSION) STATUS DOC).
-Return (KEY [NAME VERSION STATUS DOC]), where KEY is the
+ENTRY has the form ((NAME . VERSION-LIST) STATUS SUMMARY).
+Return (KEY [NAME VERSION-STRING STATUS SUMMARY]), where KEY is the
 identifier (NAME . VERSION-LIST)."
-  (let* ((package (caar pkg))
-	 (version (cdr (car pkg)))
-	 (status  (nth 1 pkg))
-	 (doc (or (nth 2 pkg) ""))
+  (let* ((name (caar entry))
+	 (version (cdar entry))
+	 (status  (nth 1 entry))
+	 (summary (or (nth 2 entry) ""))
	 (face (cond
		((string= status "built-in")  'font-lock-builtin-face)
		((string= status "available") 'default)
@@ -1449,16 +1450,16 @@ identifier (NAME . VERSION-LIST)."
		((string= status "disabled")  'font-lock-warning-face)
		((string= status "installed") 'font-lock-comment-face)
		(t 'font-lock-warning-face)))) ; obsolete.
-    (list (cons package version)
-	  (vector (list (symbol-name package)
+    (list (cons name version)
+	  (vector (list (symbol-name name)
			'face 'link
			'follow-link t
-			'package-symbol package
+			'package-symbol name
			'action 'package-menu-describe-package)
		  (propertize (package-version-join version)
			      'font-lock-face face)
		  (propertize status 'font-lock-face face)
-		  (propertize doc 'font-lock-face face)))))
+		  (propertize summary 'font-lock-face face)))))

 (defun package-menu-refresh ()
   "Download the Emacs Lisp package archive.
@@ -1534,7 +1535,7 @@ If optional arg BUTTON is non-nil, describe its
associated package."
   (let (installed available upgrades)
     ;; Build list of installed/available packages in this buffer.
     (dolist (entry tabulated-list-entries)
-      ;; ENTRY is ((NAME . VERSION) [NAME VERSION STATUS DOC])
+      ;; ENTRY is ((NAME . VERSION-LIST) [NAME VERSION-STRING STATUS SUMMARY])
       (let ((pkg (car entry))
	    (status (aref (cadr entry) 2)))
	(cond ((equal status "installed")
@@ -1617,7 +1618,7 @@ packages marked for deletion are removed."
	     (format "Delete these %d packages (%s)? "
		     (length delete-list)
		     (mapconcat (lambda (elt)
-				  (concat (car elt) "-" (cdr elt)))
+				  (format "%s-%s" (car elt) (cdr elt)))
				delete-list
				", "))))
	  (dolist (elt delete-list)
@@ -1702,15 +1703,16 @@ The list is displayed in a buffer named `*Packages*'."
	(package-menu--generate nil t))
       ;; The package menu buffer has keybindings.  If the user types
       ;; `M-x list-packages', that suggests it should become current.
-      (switch-to-buffer buf))
+      (switch-to-buffer buf)

-    (let ((upgrades (package-menu--find-upgrades)))
-      (if upgrades
-	  (message "%d package%s can be upgraded; type `%s' to mark %s for upgrading."
-		   (length upgrades)
-		   (if (= (length upgrades) 1) "" "s")
-		   (substitute-command-keys "\\[package-menu-mark-upgrades]")
-		   (if (= (length upgrades) 1) "it" "them"))))))
+      (let ((upgrades (package-menu--find-upgrades)))
+	(if upgrades
+	    (message "%d package%s can be upgraded; type `%s' to mark %s for
upgrading."
+		     (length upgrades)
+		     (if (= (length upgrades) 1) "" "s")
+		     (substitute-command-keys "\\[package-menu-mark-upgrades]")
+		     (if (= (length upgrades) 1) "it" "them"))))
+      buf)))

 ;;;###autoload
 (defalias 'package-list-packages 'list-packages)
diff --git a/lisp/finder.el b/lisp/finder.el
index 6ccb4bf..5010c8b 100644
--- a/lisp/finder.el
+++ b/lisp/finder.el
@@ -205,12 +205,16 @@ from; the default is `load-path'."
	      (setq version (ignore-errors (version-to-list version)))
	      (setq entry (assq package package--builtins))
	      (cond ((null entry)
-		     (push (cons package (vector version nil summary))
+		     (push (cons package (make-package-desc
+					  :name package
+					  :version version
+					  :summary summary
+					  :kind 'builtin))
			   package--builtins))
		    ((eq base-name package)
		     (setq desc (cdr entry))
-		     (aset desc 0 version)
-		     (aset desc 2 summary)))
+		     (setf (package-desc-version desc) version
+			   (package-desc-summary desc) summary)))
	      (dolist (kw keywords)
		(puthash kw
			 (cons package
diff --git a/test/automated/Makefile.in b/test/automated/Makefile.in
index 5f92e21..a6323df 100644
--- a/test/automated/Makefile.in
+++ b/test/automated/Makefile.in
@@ -50,7 +50,7 @@ emacs = EMACSLOADPATH=$(lispsrc):$(test) LC_ALL=C
$(EMACS) $(EMACSOPT)
 # Common command to find subdirectories
 setwins=subdirs=`find . -type d -print`; \
	for file in $$subdirs; do \
-	   case $$file in */.* | */.*/* | */=* ) ;; \
+	   case $$file in */.* | */.*/* | */=* | ./data* ) ;; \
		*) wins="$$wins $$file" ;; \
	   esac; \
	 done
diff --git a/test/automated/data/package/archive-contents
b/test/automated/data/package/archive-contents
new file mode 100644
index 0000000..64826ea
--- /dev/null
+++ b/test/automated/data/package/archive-contents
@@ -0,0 +1,7 @@
+(1
+ (simple-single .
+                [(1 3)
+                nil "A single-file package with no dependencies" single])
+ (multi-file .
+            [(0 2 3)
+             nil "Example of a multi-file tar package" tar]))
diff --git a/test/automated/data/package/multi-file-0.2.3/README
b/test/automated/data/package/multi-file-0.2.3/README
new file mode 100644
index 0000000..affd2e9
--- /dev/null
+++ b/test/automated/data/package/multi-file-0.2.3/README
@@ -0,0 +1 @@
+This is a bare-bones readme file for the multi-file package.
diff --git a/test/automated/data/package/multi-file-0.2.3/multi-file-pkg.el
b/test/automated/data/package/multi-file-0.2.3/multi-file-pkg.el
new file mode 100644
index 0000000..64bf756
--- /dev/null
+++ b/test/automated/data/package/multi-file-0.2.3/multi-file-pkg.el
@@ -0,0 +1 @@
+(define-package "multi-file" "0.2.3" "Example of a multi-file tar package" nil)
diff --git a/test/automated/data/package/multi-file-0.2.3/multi-file-sub.el
b/test/automated/data/package/multi-file-0.2.3/multi-file-sub.el
new file mode 100644
index 0000000..e14a6a9
--- /dev/null
+++ b/test/automated/data/package/multi-file-0.2.3/multi-file-sub.el
@@ -0,0 +1,39 @@
+;;; multi-file-sub.el --- A dependent file within a package.
+
+;; Copyright (C) 2012 Free Software Foundation, Inc.
+
+;; Author: Jane Smith <jsmith@example.com>
+;; Keywords: lisp, tools
+;; Package: multi-file
+;; Version: 0.2.3
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; The main multi-file elisp source depends on this.
+
+;;; Code:
+
+(defun multi-file-frobnicate (count)
+  "Frobnicate the current buffer COUNT times."
+  (interactive "p")
+  (dotimes (frobs count)
+   (insert "frobnicated " frobs "!\n")))
+
+(provide 'multi-file-sub)
+
+;;; multi-file-sub.el ends here
diff --git a/test/automated/data/package/multi-file-0.2.3/multi-file.el
b/test/automated/data/package/multi-file-0.2.3/multi-file.el
new file mode 100644
index 0000000..5fed7d8
--- /dev/null
+++ b/test/automated/data/package/multi-file-0.2.3/multi-file.el
@@ -0,0 +1,66 @@
+;;; multi-file.el --- Example of a multi-file tar package
+
+;; Copyright (C) 2012 Free Software Foundation, Inc.
+
+;; Author: Jane Smith <jsmith@example.com>
+;; Keywords: lisp, tools
+;; Package: multi-file
+;; Version: 0.2.3
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This is the main file of the "multi-file" package.
+
+;;; Code:
+
+(require 'multi-file-sub)
+
+(defgroup multi-file nil
+  "Multi-file example"
+  :group 'development)
+
+;;;###autoload
+(defcustom multi-file-custom-var nil
+  "An example autoloaded custom variable"
+  :type 'boolean
+  :group 'multi-file)
+
+(defvar multi-file-mode-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map (kbd "C-c C-l") 'multi-file-frobnicate)
+    map)
+  "Keymap for `multi-file-mode'")
+
+
+
+;;;###autoload
+(define-derived-mode multi-file-mode text-mode "Multi"
+  "Major mode which does nothing but test things.
+
+The keys are:
+\\{multi-file-mode-map}"
+  :group 'multi-file
+  (turn-off-auto-fill)
+  (set (make-local-variable 'comment-start) ";")
+  (setq case-fold-search nil))
+
+(add-to-list 'auto-mode-alist '("\\.multi\\'" . multi-file-mode))
+
+(provide 'multi-file)
+
+;;; multi-file.el ends here
diff --git a/test/automated/data/package/multi-file-0.2.3/multi-file.texi
b/test/automated/data/package/multi-file-0.2.3/multi-file.texi
new file mode 100644
index 0000000..be7568b
--- /dev/null
+++ b/test/automated/data/package/multi-file-0.2.3/multi-file.texi
@@ -0,0 +1,68 @@
+\input texinfo   @c -*-texinfo-*-
+@c %**start of header
+@setfilename multi-file.info
+@settitle Multi-file Example Manual 0.2.3
+@c %**end of header
+
+@copying
+This is a short example of a complete Texinfo file.
+
+Copyright @copyright{} 2012 Jane Smith
+@end copying
+
+@dircategory Emacs
+@direntry
+* Multi-file: (multi-file).           Example of a multi-file tar package
+@end direntry
+
+@titlepage
+@title Multi-file Example Manual
+@subtitle Example of a multi-file tar package
+@page
+@vskip 0pt plus 1filll
+@insertcopying
+@end titlepage
+
+@c Output the table of the contents at the beginning.
+@contents
+
+@ifnottex
+@node Top
+@top Multi-file
+
+@insertcopying
+@end ifnottex
+
+@menu
+* First Chapter:: The first chapter is the only chapter in this sample.
+* Index:: Complete index.
+@end menu
+
+
+@node First Chapter
+@chapter First Chapter
+
+@cindex chapter, first
+
+This is the first chapter.
+@cindex index entry, another
+
+Here is a numbered list.
+
+@enumerate
+@item
+This is the first item.
+
+@item
+This is the second item.
+@end enumerate
+
+
+@node Index
+@unnumbered Index
+
+@printindex cp
+
+@bye
+
+@c multi-file.texi ends here
diff --git a/test/automated/data/package/simple-single-1.3.el
b/test/automated/data/package/simple-single-1.3.el
new file mode 100644
index 0000000..a617841
--- /dev/null
+++ b/test/automated/data/package/simple-single-1.3.el
@@ -0,0 +1,32 @@
+;;; simple-single.el --- A single-file package with no dependencies
+
+;; Author: J. R. Hacker <jrh@example.com>
+;; Version: 1.3
+;; Keywords: frobnicate
+
+;;; Commentary:
+
+;; This package provides a minor mode to frobnicate and/or bifurcate
+;; any flanges you desire. To activate it, type "C-M-r M-3 butterfly"
+;; and all your dreams will come true.
+
+;;; Code:
+
+(defgroup simple-single nil "Simply a file"
+  :group 'lisp)
+
+(defcustom simple-single-super-sunday t
+  "How great is this?"
+  :type 'boolean
+  :group 'simple-single)
+
+(defvar simple-single-sudo-sandwich nil
+  "Make a sandwich?")
+
+;;;###autoload
+(define-minor-mode simple-single-mode
+  "It does good things to stuff")
+
+(provide 'simple-single)
+
+;;; simple-single.el ends here
diff --git a/test/automated/package-test.el b/test/automated/package-test.el
new file mode 100644
index 0000000..85edbe8
--- /dev/null
+++ b/test/automated/package-test.el
@@ -0,0 +1,261 @@
+;;; package-test.el --- Tests for the Emacs package system
+
+;; Author: Daniel Hackney <dan@haxney.org>
+;; Version: 1.0
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; Commentary:
+
+;; Run this from a separate Emacs instance from your main one as it
+;; messes with the installed packages. In fact, you should probably
+;; back up your `package-user-dir' just in case!
+
+;; Run this in a clean Emacs session using:
+;;
+;;     $ emacs -Q --batch -L . -l package-test.el -l ert -f
ert-run-tests-batch-and-exit
+
+;;; Code:
+
+(require 'package)
+(require 'ert)
+(require 'cl-lib)
+
+(defvar package-test-original-user-dir package-user-dir
+  "Save the old value of `package-user-dir' to be restored later.")
+
+(defvar package-test-user-dir (make-temp-name
+			       (concat temporary-file-directory "pkg-test-user-dir-"))
+  "Directory to use for installing packages during testing.")
+
+(setq package-user-dir package-test-user-dir)
+
+(defvar simple-single-desc [cl-struct-package-desc simple-single (1 3)
+						   "A single-file package with no dependencies"
+						   nil single nil]
+  "Expected `package-desc' parsed from simple-single-1.3.el.")
+
+(defvar package-test-dir (expand-file-name "data/package"
(file-name-directory load-file-name))
+  "Base directory of package test files.")
+
+(defvar package-test-fake-contents-file
+  (expand-file-name "archive-contents" package-test-dir)
+  "Path to a static copy of \"archive-contents\".")
+
+(defvar package-test-built-file-suffixes '(".tar" "/dir" "/*.info")
+  "Remove these files when cleaning up a built package.")
+
+(cl-defmacro with-package-test ((&optional &key file basedir
build-dir install) &rest body)
+  "Set up temporary locations and variables for testing."
+  (declare (indent 1))
+  `(let ((package-user-dir package-test-user-dir)
+	 (package-archives `(("gnu" . ,package-test-dir)))
+	 (old-yes-no-defn (symbol-function 'yes-or-no-p))
+	 ,@(if build-dir (list (list 'build-dir build-dir)
+			       (list 'build-tar (concat build-dir ".tar")))
+	     (list (cl-gensym)))) ;; Dummy value so `let' doesn't try to bind `nil'
+     (unwind-protect
+	 (progn
+	   ,(if basedir (list 'cd basedir))
+	   (setf (symbol-function 'yes-or-no-p) #'ignore)
+	   (unless (file-directory-p package-user-dir)
+	     (mkdir package-user-dir))
+	   (if (boundp 'build-dir)
+		(package-test-build-multifile build-dir))
+	   ,@(when install
+	       (list
+		(list 'package-refresh-contents)
+		;; The two quotes before `package-install' are required! One is
+		;; consumed by the macro expansion and the other prevents trying to
+		;; take the `symbol-value' of `package-install'
+		(list 'mapc ''package-install install)))
+	   (with-temp-buffer
+	     ,(if file
+		  (list 'insert-file-contents file))
+	     ,@body))
+       ,(if build-dir
+	    (list 'package-test-cleanup-built-files build-dir))
+       (when (file-directory-p package-test-user-dir)
+	 (delete-directory package-test-user-dir t))
+       (setf (symbol-function 'yes-or-no-p) old-yes-no-defn))))
+
+(defun package-test-install-texinfo (file)
+  "Install from texinfo FILE.
+
+FILE should be a .texinfo file relative to the current
+`default-directory'"
+  (require 'info)
+  (let* ((full-file (expand-file-name file))
+	 (info-file (replace-regexp-in-string "\\.texi\\'" ".info" full-file))
+	 (old-info-defn (symbol-function 'Info-revert-find-node)))
+    (require 'info)
+    (setf (symbol-function 'Info-revert-find-node) #'ignore)
+    (with-current-buffer (find-file-literally full-file)
+      (unwind-protect
+       (progn
+	 (require 'makeinfo)
+	 (makeinfo-buffer)
+	 ;; Give `makeinfo-buffer' a chance to finish
+	 (while compilation-in-progress
+	   (sit-for 0.1))
+	 (call-process "ginstall-info" nil nil nil
+		       (format "--info-dir=%s" default-directory)
+		       (format "%s" info-file)))
+       (kill-buffer)
+       (setf (symbol-function 'Info-revert-find-node) old-info-defn)))))
+
+(defun package-test-build-multifile (dir)
+  "Build a tar package from a multiple-file directory DIR.
+
+DIR must not have a trailing slash."
+  (let* ((pkg-dirname (file-name-nondirectory dir))
+	 (pkg-name (package-strip-version pkg-dirname))
+	 (pkg-version (match-string-no-properties 2 pkg-dirname))
+	 (tar-name (concat pkg-dirname ".tar"))
+	 (default-directory (expand-file-name dir)))
+    (package-test-install-texinfo (concat pkg-name ".texi"))
+    (setq default-directory (file-name-directory default-directory))
+    (call-process "tar" nil nil nil "-caf" tar-name pkg-dirname)))
+
+(defun package-test-suffix-matches (base suffix-list)
+  "Return file names matching BASE concatenated with each item in SUFFIX-LIST"
+  (cl-mapcan
+   '(lambda (item) (file-expand-wildcards (concat base item)))
+   suffix-list))
+
+(defun package-test-cleanup-built-files (dir)
+  "Remove files which were the result of creating a tar archive.
+
+DIR is the base name of the package directory, without the trailing slash"
+  (let* ((pkg-dirname (file-name-nondirectory dir)))
+    (dolist (file (package-test-suffix-matches dir
package-test-built-file-suffixes))
+      (delete-file file))))
+
+(defun package-test-search-tar-file (filename)
+  "Search the current buffer's `tar-parse-info' variable for FILENAME.
+
+Must called from within a `tar-mode' buffer."
+  (cl-dolist (header tar-parse-info)
+	     (let ((tar-name (tar-header-name header)))
+	      (when (string= tar-name filename)
+		(cl-return t)))))
+
+(ert-deftest package-test-buffer-info ()
+  "Parse an elisp buffer to get a `package-desc' object."
+  (with-package-test (:basedir "data/package" :file "simple-single-1.3.el")
+    (should (equal (package-buffer-info) simple-single-desc))))
+
+(ert-deftest package-test-install-single ()
+  "Install a single file without using an archive."
+  (with-package-test (:basedir "data/package" :file "simple-single-1.3.el")
+    (should (package-install-from-buffer (package-buffer-info)))
+    (let* ((simple-pkg-dir (file-name-as-directory
+			    (expand-file-name
+			     "simple-single-1.3"
+			     package-test-user-dir)))
+	   (autoloads-file (expand-file-name "simple-single-autoloads.el"
simple-pkg-dir)))
+      (should (file-directory-p simple-pkg-dir))
+      (with-temp-buffer
+	(insert-file-contents (expand-file-name "simple-single-pkg.el"
simple-pkg-dir))
+	(should (string= (buffer-string)
+			 "(define-package \"simple-single\" \"1.3\" \"A single-file
package with no dependencies\" nil)\n")))
+      (should (file-exists-p autoloads-file))
+      (should-not (get-file-buffer autoloads-file)))))
+
+(ert-deftest package-test-refresh-contents ()
+  "Parse an \"archive-contents\" file."
+  (with-package-test ()
+    (package-refresh-contents)))
+
+(ert-deftest package-test-install-single-from-archive ()
+  "Install a single package from a package archive."
+  (with-package-test ()
+    (package-refresh-contents)
+    (package-install 'simple-single)))
+
+(ert-deftest package-test-build-multifile ()
+  "Build a multi-file archive."
+  (with-package-test (:basedir "data/package" :build-dir "multi-file-0.2.3")
+    (should (file-exists-p build-tar))
+    (let ((suffixes
+	   (remove build-tar (package-test-suffix-matches
+			      build-dir
+			      package-test-built-file-suffixes))))
+      (with-current-buffer (find-file build-tar)
+	(dolist (file suffixes)
+	  (should (package-test-search-tar-file file)))
+	(kill-buffer)))))
+
+(ert-deftest package-test-install-multifile ()
+  "Check properties of the installed multi-file package."
+  (let ((autoload-file
+	 (expand-file-name "multi-file-autoloads.el"
+			   (expand-file-name
+			    "multi-file-0.2.3"
+			    package-test-user-dir)))
+	(installed-files '("dir" "multi-file.info" "multi-file-sub.elc"
+			   "multi-file-autoloads.el" "multi-file.elc"))
+	(autoload-forms '("^(defvar multi-file-custom-var"
+			  "^(custom-autoload 'multi-file-custom-var"
+			  "^(autoload 'multi-file-mode"
+			  "^(provide 'multi-file-autoloads)"))
+	(pkg-dir (file-name-as-directory
+			    (expand-file-name
+			     "multi-file-0.2.3"
+			     package-test-user-dir))))
+    (with-package-test (:basedir "data/package" :build-dir "multi-file-0.2.3"
+				   :install '(multi-file)
+				   :file autoload-file)
+      (should (package-installed-p 'multi-file))
+      (dolist (fn installed-files)
+	(should (file-exists-p (expand-file-name fn pkg-dir))))
+      (dolist (re autoload-forms)
+	(goto-char (point-min))
+	(should (re-search-forward re nil t))))))
+
+(ert-deftest package-test-tar-desc ()
+  "Examine the properties parsed from a tar package"
+  (with-package-test (:basedir "data/package" :build-dir "multi-file-0.2.3")
+    (let ((info (package-tar-file-info (expand-file-name build-tar))))
+      (should (eq (package-desc-name info) 'multi-file))
+      (should (equal (package-desc-version info) '(0 2 3)))
+      (should (equal (package-desc-summary info) "Example of a
multi-file tar package"))
+      (should (equal (package-desc-reqs info) nil))
+      (should (equal (package-desc-kind info) 'tar))
+      ;; (should (equal (package-desc-commentary info) "This is a
bare-bones readme file for the multi-file package.\n"))
+      )))
+
+(ert-deftest package-test-update-listing ()
+  "Ensure installed package status is updated."
+  (with-package-test
+   ()
+   (let ((buf (package-list-packages)))
+    (search-forward-regexp "^ +simple-single")
+    (package-menu-mark-install)
+    (package-menu-execute)
+    (should (package-installed-p 'simple-single))
+    (switch-to-buffer "*Packages*")
+    (goto-char (point-min))
+    (should (re-search-forward
"^\\s-+simple-single\\s-+1.3\\s-+installed" nil t))
+    (goto-char (point-min))
+    (should-not (re-search-forward
"^\\s-+simple-single\\s-+1.3\\s-+available" nil t))
+    (kill-buffer buf))))
+
+(provide 'package-test)
+
+;;; package-test.el ends here