* lisp/emacs-lisp/tabulated-list.el (tabulated-list-sort):

Check if column can be sorted before trying.  (Bug#21639)

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/emacs-lisp/tabulated-list.el b/lisp/emacs-lisp/tabulated-list.el
index 47ecd2b7922..4bd8a19937d 100644
--- a/lisp/emacs-lisp/tabulated-list.el
+++ b/lisp/emacs-lisp/tabulated-list.el
@@ -520,7 +520,9 @@ With a numeric prefix argument N, sort the Nth column."
                   (car (aref tabulated-list-format n))
                 (get-text-property (point)
                                    'tabulated-list-column-name))))
-    (tabulated-list--sort-by-column-name name)))
+    (if (nth 2 (assoc name (append tabulated-list-format nil)))
+        (tabulated-list--sort-by-column-name name)
+      (user-error "Cannot sort by %s" name))))
 
 (defun tabulated-list--sort-by-column-name (name)
   (when (and name (derived-mode-p 'tabulated-list-mode))