Upstream icsharpcode/ILSpy state of the touched files before 53822318d9

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

@@ -0,0 +1,63 @@
+using System;
+
+namespace ICSharpCode.Decompiler.Tests.TestCases.Correctness
+{
+	class NullPropagation
+	{
+		static void Main()
+		{
+			new NullPropagation().TestNotCoalescing();
+#if CS72
+			new NullPropagation().TestRefStructNotCoalescing();
+#endif
+		}
+
+		class MyClass
+		{
+			public string Text;
+		}
+
+		void TestNotCoalescing()
+		{
+			Console.WriteLine("TestNotCoalescing:");
+			Console.WriteLine(NotCoalescing(null));
+			Console.WriteLine(NotCoalescing(new MyClass()));
+		}
+
+		string NotCoalescing(MyClass c)
+		{
+			return c != null ? c.Text : "Hello";
+		}
+
+#if CS72
+		ref struct ByRefLikeStruct
+		{
+			public int Value;
+		}
+
+		class RefStructHolder
+		{
+			public ByRefLikeStruct Get()
+			{
+				ByRefLikeStruct result = default(ByRefLikeStruct);
+				result.Value = 42;
+				return result;
+			}
+		}
+
+		void TestRefStructNotCoalescing()
+		{
+			Console.WriteLine("TestRefStructNotCoalescing:");
+			Console.WriteLine(RefStructNotCoalescing(null).Value);
+			Console.WriteLine(RefStructNotCoalescing(new RefStructHolder()).Value);
+		}
+
+		// A by-ref-like return type cannot be turned into a ?. / ?? null-propagation: a ref struct
+		// cannot be wrapped in Nullable<T>, so that form does not compile.
+		ByRefLikeStruct RefStructNotCoalescing(RefStructHolder holder)
+		{
+			return holder != null ? holder.Get() : default(ByRefLikeStruct);
+		}
+#endif
+	}
+}