From 9f6cb4c7f82b20cebe227a5fdee0810dba45e9ab Mon Sep 17 00:00:00 2001 From: Robert Griesemer Date: Mon, 1 Feb 2010 16:14:22 -0800 Subject: Corrected broken assertion. Fixes issue 571. R=rsc CC=golang-dev http://codereview.appspot.com/198045 --- src/pkg/bignum/bignum.go | 6 ++++-- src/pkg/bignum/bignum_test.go | 6 ++++++ 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/src/pkg/bignum/bignum.go b/src/pkg/bignum/bignum.go index ee7d45ba6..485583199 100644 --- a/src/pkg/bignum/bignum.go +++ b/src/pkg/bignum/bignum.go @@ -565,16 +565,18 @@ func divmod(x, y []digit2) ([]digit2, []digit2) { t := c + digit(x[i+j]) - digit(y[j])*q c, x[i+j] = digit(int64(t)>>_W2), digit2(t&_M2) // requires arithmetic shift! } + x[k] = digit2((c + digit(x[k])) & _M2) // correct if trial digit was too large - if c+digit(x[k]) != 0 { + if x[k] != 0 { // add y c := digit(0) for j := 0; j < m; j++ { t := c + digit(x[i+j]) + digit(y[j]) c, x[i+j] = t>>_W2, digit2(t&_M2) } - assert(c+digit(x[k]) == 0) + x[k] = digit2((c + digit(x[k])) & _M2) + assert(x[k] == 0) // correct trial digit q-- } diff --git a/src/pkg/bignum/bignum_test.go b/src/pkg/bignum/bignum_test.go index 532fc9740..ade72dd1b 100644 --- a/src/pkg/bignum/bignum_test.go +++ b/src/pkg/bignum/bignum_test.go @@ -663,3 +663,9 @@ func TestNatPop(t *testing.T) { test(i, nat_one.Shl(i).Sub(nat_one).Pop() == i) } } + + +func TestIssue571(t *testing.T) { + const min_float = "4.940656458412465441765687928682213723651e-324" + RatFromString(min_float, 10) // this must not crash +} -- cgit v1.2.3