refine parse_rat

* rational.c (read_num): return the exponent instead of the
  divisor, to get rid of huge bignums.

* rational.c (parse_rat): subtract exponents instead of reduction
  of powers.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65618 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 0 deletions

diff --git a/test/ruby/test_rational.rb b/test/ruby/test_rational.rb
index c44ff0393a..b289753347 100644
--- a/test/ruby/test_rational.rb
+++ b/test/ruby/test_rational.rb
@@ -120,6 +120,9 @@ class Rational_Test < Test::Unit::TestCase
     assert_raise_with_message(ArgumentError, /\u{221a 2668}/) {
       Rational("\u{221a 2668}")
     }
+    assert_warning('') {
+      assert_predicate(Rational('1e-99999999999999999999'), :zero?)
+    }
 
     assert_raise(TypeError){Rational(Object.new)}
     assert_raise(TypeError){Rational(Object.new, Object.new)}