From df76f366a7be0a10deb4ab475ec4c5966d975ce2 Mon Sep 17 00:00:00 2001 From: nobu Date: Sat, 15 Apr 2017 15:29:09 +0000 Subject: bignum.c: fix inexact estimation * bignum.c (estimate_initial_sqrt): estimated square root is inexact if it is not equal to its ceil, needs Newton's method. [ruby-core:80696] [Bug #13440] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58366 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- test/ruby/test_integer.rb | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'test/ruby') diff --git a/test/ruby/test_integer.rb b/test/ruby/test_integer.rb index e0927c9ffe..963c6b75a4 100644 --- a/test/ruby/test_integer.rb +++ b/test/ruby/test_integer.rb @@ -488,5 +488,17 @@ class TestInteger < Test::Unit::TestCase assert_equal(exact, Integer.sqrt(x+1), "10**#{i}+1") assert_equal(exact-1, Integer.sqrt(x-1), "10**#{i}-1") end + + bug13440 = '[ruby-core:80696] [Bug #13440]' + too_big = [] + too_small = [] + 0.step(to: 50, by: 0.001) do |i| + n = (10**i).to_i + int_root = Integer.sqrt(n) + too_big << n if int_root*int_root > n + too_small << n if (int_root+1)*(int_root+1) <= n + end + assert_empty(too_big, bug13440) + assert_empty(too_small, bug13440) end end -- cgit v1.2.3