Do not consider external packages to be removable (Bug#27822)

Packages which are not directly user-installed shouldn't be autoremoved,
since they can be setup through a different path (via
`package-directory-list') where we have no authority over.
* lisp/emacs-lisp/package.el (package--user-installed-p): New
function.
(package--removable-packages): Use it.

1 files changed, 12 insertions, 1 deletions

diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index 576a9bc7e73..207c2e5c489 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -1730,6 +1730,15 @@ if it is still empty."
       (indirect indirect-deps)
       (t        (delete-dups (append direct-deps indirect-deps))))))
 
+(defun package--user-installed-p (package)
+  "Return non-nil if PACKAGE is a user-installed package.
+PACKAGE is the package name, a symbol.  Check whether the package
+was installed into `package-user-dir' where we assume to have
+control over."
+  (let* ((pkg-desc (cadr (assq package package-alist)))
+         (dir (package-desc-dir pkg-desc)))
+    (file-in-directory-p dir package-user-dir)))
+
 (defun package--removable-packages ()
   "Return a list of names of packages no longer needed.
 These are packages which are neither contained in
@@ -1739,7 +1748,9 @@ These are packages which are neither contained in
                          ;; `p' and its dependencies are needed.
                          append (cons p (package--get-deps p)))))
     (cl-loop for p in (mapcar #'car package-alist)
-             unless (memq p needed)
+             unless (or (memq p needed)
+                        ;; Do not auto-remove external packages.
+                        (not (package--user-installed-p p)))
              collect p)))
 
 (defun package--used-elsewhere-p (pkg-desc &optional pkg-list all)