From 4852c9c3100419e3976289655ede92b97ec2972e Mon Sep 17 00:00:00 2001
From: Andreas Pardeike <andreas@pardeike.net>
Date: Thu, 19 Dec 2024 18:11:04 +0100
Subject: [PATCH] adds test for #640

---
 HarmonyTests/Patching/Arguments.cs            | 18 ++++++++++++++++++
 HarmonyTests/Patching/Assets/ArgumentCases.cs | 18 ++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/HarmonyTests/Patching/Arguments.cs b/HarmonyTests/Patching/Arguments.cs
index 587bb5d3..bb6130f2 100644
--- a/HarmonyTests/Patching/Arguments.cs
+++ b/HarmonyTests/Patching/Arguments.cs
@@ -396,5 +396,23 @@ public void Test_RenamedArguments()
 			var log = RenamedArgumentsPatch.log.Join();
 			Assert.AreEqual("val1, patched, val2, hello", log);
 		}
+
+		[Test]
+		public void Test_NullableResults()
+		{
+			var res1 = new NullableResults().Method();
+			Assert.True(res1.HasValue);
+			Assert.False(res1.Value);
+
+			var harmony = new Harmony("test");
+			var processor = new PatchClassProcessor(harmony, typeof(NullableResultsPatch));
+			var patches = processor.Patch();
+			Assert.NotNull(patches, "patches");
+			Assert.AreEqual(1, patches.Count);
+
+			var res2 = new NullableResults().Method();
+			Assert.True(res2.HasValue);
+			Assert.True(res2.Value);
+		}
 	}
 }
diff --git a/HarmonyTests/Patching/Assets/ArgumentCases.cs b/HarmonyTests/Patching/Assets/ArgumentCases.cs
index 06c32479..e7996e88 100644
--- a/HarmonyTests/Patching/Assets/ArgumentCases.cs
+++ b/HarmonyTests/Patching/Assets/ArgumentCases.cs
@@ -144,6 +144,24 @@ public static void Postfix([HarmonyArgument("__instance")] RenamedArguments foo2
 		}
 	}
 
+	public class NullableResults
+	{
+		private string s = "foo";
+
+		[MethodImpl(MethodImplOptions.NoInlining)]
+		public bool? Method() => false;
+	}
+
+	[HarmonyPatch(typeof(NullableResults), nameof(NullableResults.Method))]
+	public static class NullableResultsPatch
+	{
+		public static bool Prefix(ref bool? __result)
+		{
+			__result = true;
+			return false;
+		}
+	}
+
 	public class ArgumentArrayMethods
 	{
 		public struct SomeStruct