From 7a7a1461a0492908853b1bbb682271640943db9b Mon Sep 17 00:00:00 2001
From: Josh Peterson <joshuap@unity3d.com>
Date: Mon, 30 Nov 2020 14:58:06 -0500
Subject: [PATCH] Allow different enums as return type in CreateDelegate (case
 1288796)

Allow `CreateDelegate` to have return type covariance with methods that
return `enum` or `int` types.

This is from the upstream change at https://github.com/mono/mono/commit/122494330d635205b0a8766deaeafd0d79bd3d60.
---
 mcs/class/corlib/System/Delegate.cs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/mcs/class/corlib/System/Delegate.cs b/mcs/class/corlib/System/Delegate.cs
index 958b70ce816..7447b4a9e01 100644
--- a/mcs/class/corlib/System/Delegate.cs
+++ b/mcs/class/corlib/System/Delegate.cs
@@ -158,6 +158,17 @@ namespace System
 				// Delegate covariance
 				if (!returnType.IsValueType && delReturnType.IsAssignableFrom (returnType))
 					returnMatch = true;
+				else
+				{
+					bool isDelArgEnum = delReturnType.IsEnum;
+					bool isArgEnum = returnType.IsEnum;
+					if (isArgEnum && isDelArgEnum)
+						returnMatch = Enum.GetUnderlyingType(delReturnType) == Enum.GetUnderlyingType(returnType);
+					else if (isDelArgEnum && Enum.GetUnderlyingType(delReturnType) == returnType)
+						returnMatch = true;
+					else if (isArgEnum && Enum.GetUnderlyingType(returnType) == delReturnType)
+						returnMatch = true;
+				}
 			}
 
 			return returnMatch;
-- 
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