numeric.c: Bignum 0 is not positive

* numeric.c (num_positive_p): should false on Bignum 0.
  http://twitter.com/rafaelfranca/status/600509783427391488
  [ruby-core:69173] [Feature #11151]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50538 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 19 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index d25205319c..4c9ee5462f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue May 19 13:10:08 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* numeric.c (num_positive_p): should false on Bignum 0.
+	  http://twitter.com/rafaelfranca/status/600509783427391488
+	  [ruby-core:69173] [Feature #11151]
+
 Tue May 19 11:22:28 2015  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* lib/uri/rfc2396_parser.rb (initialize_pattern):
diff --git a/numeric.c b/numeric.c
index e2f330f3bc..0620442bae 100644
--- a/numeric.c
+++ b/numeric.c
@@ -666,7 +666,7 @@ num_positive_p(VALUE num)
     }
     else if (RB_TYPE_P(num, T_BIGNUM)) {
 	if (method_basic_p(rb_cBignum))
-	    return BIGNUM_POSITIVE_P(num);
+	    return BIGNUM_POSITIVE_P(num) && !rb_bigzero_p(num);
     }
     return RTEST(compare_with_zero(num, mid));
 }
diff --git a/test/ruby/test_bignum.rb b/test/ruby/test_bignum.rb
index 2c6eda0d8e..012a5624d0 100644
--- a/test/ruby/test_bignum.rb
+++ b/test/ruby/test_bignum.rb
@@ -268,6 +268,18 @@ class TestBignum < Test::Unit::TestCase
     assert_equal(2**180, (2**80) * o)
   end
 
+  def test_positive_p
+    assert_predicate(T_ONE, :positive?)
+    assert_not_predicate(T_MONE, :positive?)
+    assert_not_predicate(T_ZERO, :positive?)
+  end
+
+  def test_negative_p
+    assert_not_predicate(T_ONE, :negative?)
+    assert_predicate(T_MONE, :negative?)
+    assert_not_predicate(T_ZERO, :negative?)
+  end
+
   def test_mul_balance
     assert_equal(3**7000, (3**5000) * (3**2000))
   end