Don't let completion break `declare' handling

* elisp-mode.el (elisp-completion-at-point): Fix to not alter
`defun-declarations-alist' by side effect (Bug #23648).

diff --git a/lisp/progmodes/elisp-mode.el b/lisp/progmodes/elisp-mode.el
index 5111f8870910b3071489efba7e10807d937ed7af..d02951dcf62262ca4e4d31941ddafac09c40f0e1 100644 (file)
--- a/lisp/progmodes/elisp-mode.el
+++ b/lisp/progmodes/elisp-mode.el
@@ -542,9 +542,9 @@ functions are annotated with \"<f>\" via the
                                         (delete-dups
                                          ;; FIXME: We should include some
                                          ;; docstring with each entry.
-                                         (append
-                                          macro-declarations-alist
-                                          defun-declarations-alist)))))
+                                         (append macro-declarations-alist
+                                                 defun-declarations-alist
+                                                 nil))))) ; Copy both alists.
                        ((and (or `condition-case `condition-case-unless-debug)
                              (guard (save-excursion
                                       (ignore-errors