[DynamicProxy] Preserve DefaultValues of proxied method's parameters

src/Castle.Core.Tests/Castle.Core.Tests.csproj

@@ -250,6 +250,8 @@
     <Compile Include="BugsReported\Core40.cs" />
     <Compile Include="BugsReported\DynProxy159.cs" />
     <Compile Include="BugsReported\DynProxy145_SynchronizationContext.cs" />
+    <Compile Include="DynamicProxy.Tests\Classes\ClassWithMethodWithParameterWithDefaultValue.cs" />
+    <Compile Include="DynamicProxy.Tests\ClassProxyWithDefaultValuesTestCase.cs" />
     <Compile Include="DynamicProxy.Tests\GenericInterfaceWithGenericMethod.cs" />
     <Compile Include="MultipleSavedAssembliesTestCase.cs" />
     <Compile Include="Components.DictionaryAdapter.Tests\AdaptingGenericDictionaryTestCase.cs" />

src/Castle.Core.Tests/DynamicProxy.Tests/ClassProxyWithDefaultValuesTestCase.cs

@@ -0,0 +1,39 @@
+// Copyright 2004-2013 Castle Project - http://www.castleproject.org/
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+namespace Castle.DynamicProxy.Tests
+{
+	using System.Linq;
+
+	using Castle.DynamicProxy.Tests.Classes;
+
+	using NUnit.Framework;
+
+	[TestFixture]
+	public class ClassProxyWithDefaultValuesTestCase : BasePEVerifyTestCase
+	{
+#if DOTNET45
+		[Test]
+		public void MethodParameterWithDefaultValue_DefaultValueIsSetOnProxiedMethodAsWell()
+		{
+			var proxiedType = generator.CreateClassProxy<ClassWithMethodWithParameterWithDefaultValue>().GetType();
+
+			var parameter = proxiedType.GetMethod("Method").GetParameters().Single(paramInfo => paramInfo.Name == "value");
+
+			Assert.True(parameter.HasDefaultValue);
+			Assert.AreEqual(3, parameter.DefaultValue);
+		}
+#endif
+	}
+}

src/Castle.Core.Tests/DynamicProxy.Tests/Classes/ClassWithMethodWithParameterWithDefaultValue.cs

@@ -0,0 +1,24 @@
+// Copyright 2004-2013 Castle Project - http://www.castleproject.org/
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+namespace Castle.DynamicProxy.Tests.Classes
+{
+	public class ClassWithMethodWithParameterWithDefaultValue
+	{
+		public virtual void Method(int? value = 3)
+		{
+
+		}
+	}
+}

src/Castle.Core/DynamicProxy/Generators/Emitters/MethodEmitter.cs

@@ -156,6 +156,12 @@ private void DefineParameters(ParameterInfo[] parameters)
 				{
 					parameterBuilder.SetCustomAttribute(attribute);
 				}
+#if DOTNET45
+				if (parameter.HasDefaultValue)
+				{
+					parameterBuilder.SetConstant(parameter.DefaultValue);
+				}
+#endif
 			}
 		}