* bignum.c (rb_big2dbl), test/ruby/test_bignum.rb (test_to_f): A negative Bignum out of Float range should be converted to -Infinity. [ruby-core:30492] [Bug #3362]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@28324 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 16 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index ea674dfdf3..6803465639 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Jun 15 10:29:00 2010  Kenta Murata  <mrkn@mrkn.jp>
+
+	* bignum.c (rb_big2dbl), test/ruby/test_bignum.rb (test_to_f):
+	  A negative Bignum out of Float range should be converted to -Infinity.
+	  [ruby-core:30492] [Bug #3362]
+
 Mon Jun 14 18:32:38 2010  Masatoshi SEKI  <m_seki@mva.biglobe.ne.jp>
 
 	* lib/drb/drb.rb: raise DRbConnError instead of ArgumentError if too
diff --git a/bignum.c b/bignum.c
index 3fa14eab14..bfbe16cbf6 100644
--- a/bignum.c
+++ b/bignum.c
@@ -1070,7 +1070,10 @@ rb_big2dbl(x)
 
     if (isinf(d)) {
 	rb_warn("Bignum out of Float range");
-	d = HUGE_VAL;
+	if (d < 0.0)
+	    d = -HUGE_VAL;
+	else
+	    d = HUGE_VAL;
     }
     return d;
 }
diff --git a/test/ruby/test_bignum.rb b/test/ruby/test_bignum.rb
index 99c5952173..a0405ca274 100644
--- a/test/ruby/test_bignum.rb
+++ b/test/ruby/test_bignum.rb
@@ -103,4 +103,10 @@ class TestBignum < Test::Unit::TestCase
     e = assert_raise(RangeError) {(1 << big).to_s}
     assert_match(/too big to convert/, e.message)
   end
+
+  def test_to_f
+    inf = 1 / 0.0
+    assert_equal(inf,  (1  << 65536).to_f)
+    assert_equal(-inf, (-1 << 65536).to_f) # [ruby-core:30492] [Bug #3362]
+  end
 end