Avoid duplicate VC packages in 'package-selected-packages'

* lisp/emacs-lisp/package-vc.el (package-vc--unpack-1): Check if
'package-selected-packages' already contains the package name.
(bug#63338)

1 files changed, 5 insertions, 3 deletions

diff --git a/lisp/emacs-lisp/package-vc.el b/lisp/emacs-lisp/package-vc.el
index 1fcc30595da..17e93c430c9 100644
--- a/lisp/emacs-lisp/package-vc.el
+++ b/lisp/emacs-lisp/package-vc.el
@@ -506,9 +506,11 @@ documentation and marking the package as installed."
         (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