[BUG]使用Contract.Requires< T>在类的ctor中使用委托抛出NullReferenceException

问题描述

重现的例子：

class Program
    {
        static void Main(string[] args)
        {
            var test = new Test("Haha", Guid.Empty);

        }
    }

    public class Test
    {
        private readonly int _id;

        public Test(string haha, Guid actionGuid)
        {
            Contract.Requires<ArgumentNullException>(haha != null);

            TestMethod(() => TestMethod(actionGuid));
        }

        private void TestMethod(Action action)
        {
            action();
        }

        private void TestMethod(Guid haha)
        {
            
        }
    }

在此示例中，输入参数"actionGuild"用于lambda表达式，paramater用于闭包。此代码的重写器生成无效语句。

In this example input parameter "actionGuild" is used in lambda expression and it paramater is closure. Rewriter for this code generate invalid statements.

反编译代码：

public class Test
  {
    private readonly int _id;

    public Test(string haha, Guid actionGuid)
    {
      __ContractsRuntime.Requires<ArgumentNullException>(haha != null, (string) null, "haha != null");
      Action action1 = (Action) null;
      Test.\u003C\u003Ec__DisplayClass2 cDisplayClass2_1 = new Test.\u003C\u003Ec__DisplayClass2();
      cDisplayClass2_1.actionGuid = actionGuid;
      base.\u002Ector();
      cDisplayClass2_1.\u003C\u003E4__this = this;
      Test test = this;
      if (action1 == null)
      {
        // ISSUE: method pointer
        action1 = new Action((object) cDisplayClass2_1, __methodptr(\u003C\u002Ector\u003Eb__0));
      }
      Action action2 = action1;
      test.TestMethod(action2);

Test.\\\c__DisplayClass2 cDisplayClass2_2;
cDisplayClass2_2.\\\4__this = this;
}

private void TestMethod（Action action）
{
action（）;
}

private void TestMethod（Guid haha​​）
{
}

[CompilerGenerated]
私人密封班\ u003C\\\>c__DisplayClass2
{
public Test \ u003C \ u003E4__this;
public Guid actionGuid;

public \\\c__DisplayClass2（）
{
base.\\\.ctor（）;
}

public void \\\b__0（）
{
this.\\\4__this.TestMethod（this.actionGuid） ;
}
}
}

Test.\u003C\u003Ec__DisplayClass2 cDisplayClass2_2; cDisplayClass2_2.\u003C\u003E4__this = this; } private void TestMethod(Action action) { action(); } private void TestMethod(Guid haha) { } [CompilerGenerated] private sealed class \u003C\u003Ec__DisplayClass2 { public Test \u003C\u003E4__this; public Guid actionGuid; public \u003C\u003Ec__DisplayClass2() { base.\u002Ector(); } public void \u003C\u002Ector\u003Eb__0() { this.\u003C\u003E4__this.TestMethod(this.actionGuid); } } }

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