From f0ff0d3630b2d1100aedc0b26a04f659341b9014 Mon Sep 17 00:00:00 2001
From: Brian Fiete <bfiete@gmail.com>
Date: Tue, 1 Mar 2022 10:37:13 -0800
Subject: [PATCH] Improved null handling in reflected method invocation

---
 BeefLibs/corlib/src/Reflection/MethodInfo.bf | 52 ++++++++++++++++++--
 BeefLibs/corlib/src/System.bf                | 15 ++++++
 2 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/BeefLibs/corlib/src/Reflection/MethodInfo.bf b/BeefLibs/corlib/src/Reflection/MethodInfo.bf
index af81e65f..2b0dd4d4 100644
--- a/BeefLibs/corlib/src/Reflection/MethodInfo.bf
+++ b/BeefLibs/corlib/src/Reflection/MethodInfo.bf
@@ -595,13 +595,51 @@ namespace System.Reflection
 				bool unbox = false;
 				bool unboxToPtr = false;
 
-				let argType = arg.[Friend]RawGetType();
-				void* dataPtr = (uint8*)Internal.UnsafeCastToPtr(arg) + argType.[Friend]mMemberDataOffset;
+				void* nullPtr = null;
+
+				Type argType = null;
+				void* dataPtr = null;
+
 				bool isValid = true;
-
 				bool added = false;
+				bool handled = false;
 
-				if (var refParamType = paramType as RefType)
+				if (arg == null)
+				{
+					isValid = false;
+
+					if ((paramType.IsPointer) || (paramType.IsObject) || (paramType.IsInterface))
+					{
+						argType = paramType;
+						dataPtr = &nullPtr;
+						isValid = true;
+					}
+					else if (var genericType = paramType as SpecializedGenericType)
+					{
+						if (genericType.UnspecializedType == typeof(Nullable<>))
+						{
+							argType = paramType;
+							dataPtr = ScopedAllocZero!(paramType.Size, 16);
+							isValid = true;
+							handled = true;
+						}
+					}
+				}
+				else
+				{
+					argType = arg.[Friend]RawGetType();
+					dataPtr = (uint8*)Internal.UnsafeCastToPtr(arg) + argType.[Friend]mMemberDataOffset;
+				}
+
+				if (!isValid)
+				{
+					// Not valid
+				}
+				else if (handled)
+				{
+					
+				}
+				else if (var refParamType = paramType as RefType)
 				{
 					if (argType.IsBoxedStructPtr || argType.IsBoxedPrimitivePtr)
 					{
@@ -633,7 +671,7 @@ namespace System.Reflection
 				}
 				else if (paramType.IsValueType)
 				{
-					bool handled = true;
+					handled = true;
 
 					if (!argType.IsBoxed)
 						return .Err(.InvalidArgument((.)argIdx));
@@ -647,6 +685,10 @@ namespace System.Reflection
 						dataPtr = *(void**)dataPtr;
 						handled = true;
 					}
+					else
+					{
+						isValid = underlyingType == paramType;
+					}
 					
 					if (!handled)
 					{
diff --git a/BeefLibs/corlib/src/System.bf b/BeefLibs/corlib/src/System.bf
index 9289da0a..a2386735 100644
--- a/BeefLibs/corlib/src/System.bf
+++ b/BeefLibs/corlib/src/System.bf
@@ -273,4 +273,19 @@ static
 		}
 		data
 	}
+
+	public static mixin ScopedAllocZero(int size, int align)
+	{
+		void* data;
+		if (size <= 128)
+		{
+			data = scope:mixin [Align(align)] uint8[size]*;
+		}
+		else
+		{
+			data = new [Align(align)] uint8[size]*;
+			defer:mixin delete data;
+		}
+		data
+	}
 }
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