Use __send__ instead of send

lib/rspec/core/output_wrapper.rb

@@ -15,13 +15,13 @@ def respond_to?(name, priv=false)
       end
 
       def method_missing(name, *args, &block)
-        output.send(name, *args, &block)
+        output.__send__(name, *args, &block)
       end
 
       # Redirect calls for IO interface methods
       IO.instance_methods(false).each do |method|
         define_method(method) do |*args, &block|
-          output.send(method, *args, &block)
+          output.__send__(method, *args, &block)
         end
       end
     end

spec/rspec/core/output_wrapper_spec.rb

@@ -9,6 +9,11 @@ module RSpec::Core
       expect(output.string).to eq("message\nanother message").and eq(wrapper.string)
     end
 
+    it 'proxies IO instance methods with __send__ to be compatiable with IOs that redefine send' do
+      expect(output).to receive(:__send__).with(:puts, 'message')
+      wrapper.puts('message')
+    end
+
     describe '#output=' do
       let(:another_output) { StringIO.new }