bug#62720: 29.0.60; Not easy at all to upgrade :core packages like Eglot

[João Távora]

Eli Zaretskii <eliz@gnu.org> writes:

> the restrictions.  What else can I say to express clearly that I would
> like such a command to not be installed?

Had another idea: what about this very tiny patch, then?  It makes `M-x
package-install` work for installing a :core package.  This also rhymes
exactly with Stefan's intution/feeling that :core packages need to be
"installed" to promote them to installable.  The current M-x
package-install recommendation could remain flawlessly and then you can
do whatever you think is best for M-x package-update & friends.

diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index f92afe56b76..134505a96af 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -2164,8 +2164,10 @@ package-installed-p
        (and pkg-descs
             (version-list-<= min-version
                              (package-desc-version (car pkg-descs)))))
-     ;; Also check built-in packages.
-     (package-built-in-p package min-version)))))
+     ;; Also check built-in packages.  But if min-version is nil, just
+     ;; act as if a package-desc had been passed (bug#62720)
+     (and min-version (package-built-in-p package min-version))))))
 
 (defun package-download-transaction (packages)
   "Download and install all the packages in PACKAGES.

João