[CodeActions] PutInsideUsingAction: remove trailing Dispose() invocation

ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/PutInsideUsingAction.cs

@@ -29,6 +29,7 @@ using System.Linq;
 using ICSharpCode.NRefactory.CSharp.Resolver;
 using ICSharpCode.NRefactory.Semantics;
 using ICSharpCode.NRefactory.TypeSystem;
+using ICSharpCode.NRefactory.PatternMatching;
 
 namespace ICSharpCode.NRefactory.CSharp.Refactoring
 {
@@ -99,6 +100,11 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 					foreach (var decl in variableToMoveOutside)
 						script.InsertBefore (variableDecl, decl);
 
+					if (body.Statements.Count > 0) {
+						var lastStatement = body.Statements.Last ();
+						if (IsDisposeInvocation (resolveResult.Variable.Name, lastStatement))
+							lastStatement.Remove ();
+					}
 					var usingStatement = new UsingStatement
 					{
 						ResourceAcquisition = new VariableDeclarationStatement (variableDecl.Type.Clone (), node.Name,
@@ -143,5 +149,12 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 				}, context.CancellationToken);
 			return lastReference;
 		}
+
+		static bool IsDisposeInvocation (string variableName, Statement statement)
+		{
+			var memberReferenceExpr = new MemberReferenceExpression (new IdentifierExpression (variableName), "Dispose");
+			var pattern = new ExpressionStatement (new InvocationExpression (memberReferenceExpr));
+			return pattern.Match (statement).Success;
+		}
 	}
 }

ICSharpCode.NRefactory.Tests/CSharp/CodeActions/PutInsideUsingTests.cs

@@ -185,6 +185,30 @@ class TestClass
 		}
 		a++;
 	}
+}");
+		}
+
+		[Test]
+		public void TestRemoveDisposeInvocation ()
+		{
+			Test<PutInsideUsingAction> (@"
+class TestClass
+{
+	void TestMethod ()
+	{
+		System.IDisposable obj $= null;
+		obj.Method ();
+		obj.Dispose();
+	}
+}", @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		using (System.IDisposable obj = null) {
+			obj.Method ();
+		}
+	}
 }");
 		}
 	}