Signal user-error on duplicate package refresh

* lisp/emacs-lisp/package.el (package-menu-refresh): Signal a
user-error if there is already a refresh running in the
background.  Doc fix.  (Bug#36707)

diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index a72522ad8f80bc07cda33dc32f251b805d555444..4e0c0464d480cccb57c36e9d689ebc60a14abc92 100644 (file)
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -3086,12 +3086,15 @@ Return (PKG-DESC [NAME VERSION STATUS DOC])."
   "`package-archive-contents' before the latest refresh.")
 
 (defun package-menu-refresh ()
-  "Download the Emacs Lisp package archive.
-This fetches the contents of each archive specified in
-`package-archives', and then refreshes the package menu."
+  "In Package Menu, download the Emacs Lisp package archive.
+Fetch the contents of each archive specified in
+`package-archives', and then refresh the package menu.  Signal a
+user-error if there is already a refresh running asynchronously."
   (interactive)
   (unless (derived-mode-p 'package-menu-mode)
     (user-error "The current buffer is not a Package Menu"))
+  (when (and package-menu-async package--downloads-in-progress)
+    (user-error "Package refresh is already in progress, please wait..."))
   (setq package-menu--old-archive-contents package-archive-contents)
   (setq package-menu--new-package-list nil)
   (package-refresh-contents package-menu-async))