1 files changed, 3 insertions, 2 deletions

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index dd7e042499c..61f7268adff 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -534,6 +534,7 @@
                     (eq tmp 'error-free)
                     ;; Detect the expansion of (pop foo).
                     ;; There is no need to compile the call to `car' there.
+                    (progn (setq foo (list form fn)) nil)
                     (and (eq fn 'car)
                          (eq (car-safe (cadr form)) 'prog1)
                          (let ((var (cadr (cadr form)))
@@ -545,8 +546,8 @@
                                 (eq (car-safe (nth 2 last)) 'cdr)
                                 (eq (cadr (nth 2 last)) var))))
                     (progn
-                      (byte-compile-warn "value returned by `%s' is not used"
-                                         (prin1-to-string (car form)))
+                      (byte-compile-warn "value returned from %s is unused"
+                                         (prin1-to-string form))
                       nil)))
            (byte-compile-log "  %s called for effect; deleted" fn)
            ;; appending a nil here might not be necessary, but it can't hurt.