Subject: Re: bug#19390: Acknowledgement (25.0.50; `package-activate' is too slow)

From: Dmitry Gutov <[email-masked]>
Date: Tue, 16 Dec 2014 02:41:58 +0200

Here's one possible fix. We don't deal with the slowness of 
`package--list-loaded-files' at all, and instead only load them if 
`package-activate' had been called with non-nil second argument (which 
only happens now if the package is installed).

This also changes the way `package-activate' calls itself recursively on 
dependencies: instead of always passing the version as the second 
argument, pass the same value of FORCE it's been called with. Passing 
the version seems to be a remnant of older code.

diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index cd948ae..394efc3 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -516,7 +516,7 @@ Return the max version (as a string) if the package 
is held at a lower version."
               force))
            (t (error "Invalid element in `package-load-list'")))))

-(defun package-activate-1 (pkg-desc)
+(defun package-activate-1 (pkg-desc &optional force)
    (let* ((name (package-desc-name pkg-desc))
  	 (pkg-dir (package-desc-dir pkg-desc))
           (pkg-dir-dir (file-name-as-directory pkg-dir)))
@@ -527,7 +527,7 @@ Return the max version (as a string) if the package 
is held at a lower version."
      (let* ((old-lp load-path)
             (autoloads-file (expand-file-name
                              (format "%s-autoloads" name) pkg-dir))
-           (loaded-files-list (package--list-loaded-files pkg-dir)))
+           (loaded-files-list (and force (package--list-loaded-files 
pkg-dir))))
        (with-demoted-errors (format "Error loading %s: %%s" name)
          (load autoloads-file nil t))
        (when (and (eq old-lp load-path)
@@ -636,14 +636,14 @@ If FORCE is true, (re-)activate it if it's already 
activated."
               (fail (catch 'dep-failure
                       ;; Activate its dependencies recursively.
                       (dolist (req (package-desc-reqs pkg-vec))
-                       (unless (package-activate (car req) (cadr req))
+                       (unless (package-activate (car req) force)
                           (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)))
  	  ;; If all goes well, activate the package itself.
-	  (package-activate-1 pkg-vec)))))))
+	  (package-activate-1 pkg-vec force)))))))

  (defun define-package (_name-string _version-string
                                      &optional _docstring _requirements