Add a unit test validating that COM V-table ordering doesn't change with mixed properties, methods, and events

ICSharpCode.Decompiler.Tests/CorrectnessTestRunner.cs

@@ -391,6 +391,12 @@ namespace ICSharpCode.Decompiler.Tests
 			await RunCS(options: options);
 		}
 
+		[Test]
+		public async Task ComInterop([ValueSource(nameof(noMonoOptions))] CompilerOptions options)
+		{
+			await RunCS(options: options);
+		}
+
 		async Task RunCS([CallerMemberName] string testName = null, CompilerOptions options = CompilerOptions.UseDebug)
 		{
 			if ((options & CompilerOptions.UseRoslynMask) != 0 && (options & CompilerOptions.TargetNet40) == 0)

ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj

@@ -106,6 +106,7 @@
     <Compile Include="Output\InsertParenthesesVisitorTests.cs" />
     <Compile Include="ProjectDecompiler\TargetFrameworkTests.cs" />
     <Compile Include="TestAssemblyResolver.cs" />
+    <Compile Include="TestCases\Correctness\ComInterop.cs" />
     <Compile Include="TestCases\Correctness\DeconstructionTests.cs" />
     <Compile Include="TestCases\Correctness\DynamicTests.cs" />
     <Compile Include="TestCases\Correctness\StringConcat.cs" />

ICSharpCode.Decompiler.Tests/TestCases/Correctness/ComInterop.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace ICSharpCode.Decompiler.Tests.TestCases.Correctness
+{
+	public class ComInterop
+	{
+		public static void Main()
+		{
+			Console.WriteLine(Marshal.GetComSlotForMethodInfo(typeof(IMixedPropsAndMethods).GetMethod("MyMethod1")));
+			Console.WriteLine(Marshal.GetComSlotForMethodInfo(typeof(IMixedPropsAndMethods).GetProperty("MyProperty1").GetMethod));
+			Console.WriteLine(Marshal.GetComSlotForMethodInfo(typeof(IMixedPropsAndMethods).GetMethod("MyMethod2")));
+			Console.WriteLine(Marshal.GetComSlotForMethodInfo(typeof(IMixedPropsAndMethods).GetProperty("MyProperty2").GetMethod));
+			Console.WriteLine(Marshal.GetComSlotForMethodInfo(typeof(IMixedPropsAndMethods).GetProperty("MyProperty2").SetMethod));
+			Console.WriteLine(Marshal.GetComSlotForMethodInfo(typeof(IMixedPropsAndMethods).GetEvent("MyEvent1").AddMethod));
+			Console.WriteLine(Marshal.GetComSlotForMethodInfo(typeof(IMixedPropsAndMethods).GetEvent("MyEvent1").RemoveMethod));
+		}
+
+
+		[Guid("761618B8-3994-449A-A96B-F1FF2795EA85")]
+		[ComImport]
+		[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+		internal interface IMixedPropsAndMethods
+		{
+			int MyMethod1();
+
+			int MyProperty1 { get; }
+
+			int MyMethod2();
+
+			int MyProperty2 { get; set; }
+
+			event EventHandler MyEvent1;
+
+			int MyMethod3();
+		}
+	}
+}