* ext/bigdecimal/lib/bigdecimal/util.rb (Rational#to_d):

  zero or negative precision is error.  fixes #5098.
  [ruby-dev:44210]
* test/bigdecimal/test_bigdecimal_util.rb: add test for the above
  change.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32680 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 15 insertions, 0 deletions

diff --git a/test/bigdecimal/test_bigdecimal_util.rb b/test/bigdecimal/test_bigdecimal_util.rb
index 87b4f20e99..72342b922f 100644
--- a/test/bigdecimal/test_bigdecimal_util.rb
+++ b/test/bigdecimal/test_bigdecimal_util.rb
@@ -25,4 +25,19 @@ class TestBigDecimalUtil < Test::Unit::TestCase
     assert_in_delta(BigDecimal(0.5, 5), 0.5.to_d(digits), delta)
     assert_in_delta(BigDecimal(355.0/113.0, 5), (355.0/113.0).to_d(digits), delta)
   end
+
+  def test_Rational_to_d
+    digits = 100
+    delta = 1.0/10**(digits)
+    assert_in_delta(BigDecimal(1.quo(2), digits), 1.quo(2).to_d(digits), delta)
+    assert_in_delta(BigDecimal(355.quo(113), digits), 355.quo(113).to_d(digits), delta)
+  end
+
+  def test_Rational_to_d_with_zero_precision
+    assert_raise(ArgumentError) { 355.quo(113).to_d(0) }
+  end
+
+  def test_Rational_to_d_with_negative_precision
+    assert_raise(ArgumentError) { 355.quo(113).to_d(-42) }
+  end
 end