On 13 May 2023 at 6:18 PM +0100, Philip Kaludercic <philipk@posteo.net>, wrote:

ping?

Philip Kaludercic <philipk@posteo.net> writes:

Jimmy Wong <wyuenho@gmail.com> writes:

I don’t think you should dedup the variable that could have been
modified by something else such as package-install. This may make
debugging harder should package.el itself introduce a bug that
duplicates pacakages in the variable. How about just using good old
add-to-list?

The issue is that we want to go through package--save-selected-packages,
that is given a new value to assign to `package-selected-packages'.
An otherwise, I my understanding is that add-to-list is not conventional
in executed code.

The alternative is to check for duplicates before invoking the function:

diff --git a/lisp/emacs-lisp/package-vc.el b/lisp/emacs-lisp/package-vc.el
index e9794eac783..b967aaa3d4d 100644
--- a/lisp/emacs-lisp/package-vc.el
+++ b/lisp/emacs-lisp/package-vc.el
@@ -507,9 +507,10 @@ package-vc--unpack-1
(package--reload-previously-loaded new-desc)))

;; Mark package as selected
- (package--save-selected-packages
- (cons (package-desc-name pkg-desc)
- package-selected-packages))
+ (let ((name (package-desc-name pkg-desc)))
+ (unless (memq name package-selected-packages)
+ (package--save-selected-packages
+ (cons name package-selected-packages))))
(package--quickstart-maybe-refresh)

;; Confirm that the installation was successful

On 8 May 2023 at 1:03 PM +0100, Eli Zaretskii <eliz@gnu.org>, wrote:

Cc: 63338@debbugs.gnu.org
From: Philip Kaludercic <philipk@posteo.net>
Date: Mon, 08 May 2023 10:36:55 +0000

Jimmy Yuen Ho Wong <wyuenho@gmail.com> writes:

Reproduction:

0. (setq custom-file (const user-emacs-directory "custom.el"))
1. M-x package-vc-install company
2. M-x package-vc-install company RET y
3. C-x C-f ~/.emacs/custom.el
4. Observe that `company` has been listed twice under
`package-selected-packages`.

Expectation:

Installing the same package twice should not result in its duplication
in `package-selected-packages`.

An easy fix would be just to ensure that package-selected-packages is
always deduplicated before assigning the value:

This is OK for the emacs-29 branch, thanks.