(byte-optimize-plus): Fix 1-arg case.

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index cfec516..4f399f4 100644 (file)
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -700,6 +700,10 @@
 ;;; (actually, it would be safe if we know the sole arg
 ;;; is not a marker).
 ;;     ((null (cdr (cdr form))) (nth 1 form))
+       ((null (cddr form))
+        (if (numberp (nth 1 form))
+            (nth 1 form)
+          form))
        ((and (null (nthcdr 3 form))
              (or (memq (nth 1 form) '(1 -1))
                  (memq (nth 2 form) '(1 -1))))