4878_cmath.patch

diff --git a/lib/cmath.rb b/lib/cmath.rb
index e21f9d8..16e0c49 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -305,14 +305,14 @@ module CMath
   module_function :atanh!
   module_function :atanh
 
-  module_function :frexp
-  module_function :ldexp
-  module_function :hypot
   module_function :erf
   module_function :erfc
   module_function :gamma
   module_function :lgamma
 
+  undef :frexp
+  undef :ldexp
+  undef :hypot
 end
 
 class Object
diff --git a/lib/complex.rb b/lib/complex.rb
index 9c57ecd..056111c 100644
--- a/lib/complex.rb
+++ b/lib/complex.rb
@@ -5,7 +5,16 @@ warn('lib/complex.rb is deprecated') if $VERBOSE
 require 'cmath'
 
 unless defined?(Math.exp!)
-  Object.instance_eval{remove_const :Math}
+  module CMath
+    math = Object.instance_eval{remove_const :Math}
+    define_method(:frexp) {|x|    math.frexp(x)    }
+    define_method(:ldexp) {|x, e| math.ldexp(x, e) }
+    define_method(:hypot) {|x, y| math.hypot(x, y) }
+
+    module_function :frexp
+    module_function :ldexp
+    module_function :hypot
+  end
   Math = CMath
 end
 
diff --git a/test/test_cmath.rb b/test/test_cmath.rb
index 4f85ec3..17bec09 100644
--- a/test/test_cmath.rb
+++ b/test/test_cmath.rb
@@ -9,4 +9,16 @@ class TestCMath < Test::Unit::TestCase
   def test_cbrt_returns_principal_value_of_cube_root
     assert_equal CMath.cbrt(-8), (-8)**(1.0/3), '#3676'
   end
+
+  def test_frexp_is_undefined
+    assert(!CMath.methods.include?(:frexp))
+  end
+
+  def test_ldexp_is_undefined
+    assert(!CMath.methods.include?(:ldexp))
+  end
+
+  def test_hypot_is_undefined
+    assert(!CMath.methods.include?(:hypot))
+  end
 end
diff --git a/test/test_complex.rb b/test/test_complex.rb
new file mode 100644
index 0000000..5b384b9
--- /dev/null
+++ b/test/test_complex.rb
@@ -0,0 +1,72 @@
+require 'test/unit'
+require_relative 'ruby/envutil'
+
+class TestComplex < Test::Unit::TestCase
+  def test_Math_respond_to_frexp
+    assert_in_out_err([], <<-INPUT, %w(:ok), [])
+      require 'complex'
+      exit unless Math.respond_to?(:frexp)
+      p :ok
+    INPUT
+  end
+
+  def test_Math_frexp
+    assert_in_out_err([], <<-INPUT, %w(:ok), [])
+      require 'complex'
+      [ [ 0.0, 0.0, 0 ],
+        [ 0.5, 0.5, 0 ],
+        [ 2.0, 0.5, 2 ],
+      ].each_with_index do |(x, y, e), i|
+        unless (Math.frexp(x).first - y).abs < 1e-6
+          p "invalid y - %d" % [i]
+          exit
+        end
+        unless Math.frexp(x).last == e
+          p "invalid e - %d" % [i]
+          exit
+        end
+      end
+      p :ok
+    INPUT
+  end
+
+  def test_Math_respond_to_ldexp
+    assert_in_out_err([], <<-INPUT, %w(:ok), [])
+      require 'complex'
+      exit unless Math.respond_to?(:ldexp)
+      p :ok
+    INPUT
+  end
+
+  def test_Math_ldexp
+    assert_in_out_err([], <<-INPUT, %w(:ok), [])
+      require 'complex'
+      [ [ 0.0, 0.0, 0.0 ],
+        [ 0.5, 0.0, 0.5 ],
+        [ 0.5, 2.0, 2.0 ],
+      ].each_with_index do |(x, e, rv), i|
+        unless (Math.ldexp(x, e) - rv).abs < 1e-6
+          p "fail %d" % [i]
+          exit
+        end
+      end
+      p :ok
+    INPUT
+  end
+
+  def test_Math_respond_to_hypot
+    assert_in_out_err([], <<-INPUT, %w(:ok), [])
+      require 'complex'
+      exit unless Math.respond_to?(:hypot)
+      p :ok
+    INPUT
+  end
+
+  def test_hypot
+    assert_in_out_err([], <<-INPUT, %w(:ok), [])
+      require 'complex'
+      exit unless Math.hypot(3, 4) == 5
+      p :ok
+    INPUT
+  end
+end