rational.c: fix for mathn

* rational.c (read_num, read_rat_nos): dispatch by the type of numerator, for
  mathn.  [ruby-core:78893] [Bug #13084]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57232 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 9 insertions, 0 deletions

diff --git a/test/test_mathn.rb b/test/test_mathn.rb
index 00130eadf1..b50a09e4df 100644
--- a/test/test_mathn.rb
+++ b/test/test_mathn.rb
@@ -180,4 +180,13 @@ class TestMathn < Test::Unit::TestCase
       assert_equal((-13/5), (-13/5).round(2, half: :down))
     EOS
   end
+
+  def test_rational
+    assert_separately(%w[-rmathn], "#{<<-"begin;"}\n#{<<-"end;"}", ignore_stderr: true)
+    begin;
+      assert_equal(-5, "-5".to_r)
+      assert_equal(1, "5/5".to_r)
+      assert_equal(5, "5e0".to_r)
+    end;
+  end
 end