From 708dc66d7b8dd5bd4f66558cd6a61502b6b68b43 Mon Sep 17 00:00:00 2001 From: Leo Liu Date: Fri, 27 Jun 2014 12:10:04 +0800 Subject: [PATCH] Backport fix for http://debbugs.gnu.org/17556 from trunk * lisp/calc/calc.el (math-bignum): Handle most-negative-fixnum. --- lisp/ChangeLog | 4 ++++ lisp/calc/calc.el | 15 ++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/lisp/ChangeLog b/lisp/ChangeLog index a2cb2845bc7..dcbb027e94f 100644 --- a/lisp/ChangeLog +++ b/lisp/ChangeLog @@ -1,3 +1,7 @@ +2014-06-27 Leo Liu + + * calc/calc.el (math-bignum): Handle most-negative-fixnum. (Bug#17556) + 2014-06-27 Glenn Morris * net/eww.el (eww-mode) : Make local. (Bug#17860) diff --git a/lisp/calc/calc.el b/lisp/calc/calc.el index ba1c7de9967..04d852e5cb3 100644 --- a/lisp/calc/calc.el +++ b/lisp/calc/calc.el @@ -2773,9 +2773,18 @@ largest Emacs integer.") ;; Coerce integer A to be a bignum. [B S] (defun math-bignum (a) - (if (>= a 0) - (cons 'bigpos (math-bignum-big a)) - (cons 'bigneg (math-bignum-big (- a))))) + (cond + ((>= a 0) + (cons 'bigpos (math-bignum-big a))) + ((= a most-negative-fixnum) + ;; Note: cannot get the negation directly because + ;; (- most-negative-fixnum) is most-negative-fixnum. + ;; + ;; most-negative-fixnum := -most-positive-fixnum - 1 + (math-sub (cons 'bigneg (math-bignum-big most-positive-fixnum)) + 1)) + (t + (cons 'bigneg (math-bignum-big (- a)))))) (defun math-bignum-big (a) ; [L s] (if (= a 0) -- 2.39.5