X-Git-Url: http://git.chise.org/gitweb/?p=chise%2Fxemacs-chise.git.1;a=blobdiff_plain;f=lisp%2Fbyte-optimize.el;h=dad9de8f5e03f14766a8bf59d48afb3cb0f23b79;hp=f591e82d5c6710e6aa800aee828cb8932e001ff1;hb=efdb31fd4c8db81d2414c32d491f1bf994263c74;hpb=75d621fb12f4d3bc3e2eecefac39fe62eecbd431

diff --git a/lisp/byte-optimize.el b/lisp/byte-optimize.el
index f591e82..dad9de8 100644
--- a/lisp/byte-optimize.el
+++ b/lisp/byte-optimize.el
@@ -729,9 +729,15 @@
       (decf (nth 1 form) last)
       (butlast form))
 
-     ;; (- 0 x ...)  -->  (- (- x) ...)
-     ((and (eq 0 (nth 1 form)) (>= (length form) 3))
-      `(- (- ,(nth 2 form)) ,@(nthcdr 3 form)))
+     ;; (- 0 ...) -->
+     ((eq 0 (nth 1 form))
+      (case (length form)
+	;; (- 0) --> 0
+	(2 0)
+	;; (- 0 x)  -->  (- x)
+	(3 `(- ,(nth 2 form)))
+	;; (- 0 x y ...)  -->  (- (- x) y ...)
+	(t `(- (- ,(nth 2 form)) ,@(nthcdr 3 form)))))
 
      (t (byte-optimize-predicate form)))))