From dab013b9e61327ae4a992f05f1ad6a2f0d8b689f Mon Sep 17 00:00:00 2001
From: Jeffrey Stedfast <jestedfa@microsoft.com>
Date: Fri, 30 Aug 2024 13:29:06 -0400
Subject: [PATCH] Fixed NullableAttributes

---
 MimeKit/MimeKit.csproj        |  2 --
 MimeKit/MimeKitLite.csproj    |  2 --
 MimeKit/NullableAttributes.cs | 50 +++++++++++++++++++----------------
 3 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/MimeKit/MimeKit.csproj b/MimeKit/MimeKit.csproj
index dcc736e0a3..b485c38f14 100644
--- a/MimeKit/MimeKit.csproj
+++ b/MimeKit/MimeKit.csproj
@@ -95,8 +95,6 @@
     <Compile Remove="Cryptography\LdapUri.cs" />
     <Compile Remove="Utils\OptimizedOrdinalComparer.cs" />
     <Compile Include="Utils\OptimizedOrdinalComparer.cs" Condition=" $(TargetFramework.StartsWith('net4')) Or '$(TargetFramework)' == 'netstandard2.0' " />
-    <Compile Remove="NullableAttributes.cs" />
-    <Compile Include="NullableAttributes.cs" Condition=" $(TargetFramework.StartsWith('net4')) Or '$(TargetFramework)' == 'netstandard2.0' " />
   </ItemGroup>
 
 </Project>
diff --git a/MimeKit/MimeKitLite.csproj b/MimeKit/MimeKitLite.csproj
index fd6e79f31f..8eb7103a7c 100644
--- a/MimeKit/MimeKitLite.csproj
+++ b/MimeKit/MimeKitLite.csproj
@@ -71,8 +71,6 @@
     <Compile Include="Cryptography\AuthenticationResults.cs" />
     <Compile Remove="Utils\OptimizedOrdinalComparer.cs" />
     <Compile Include="Utils\OptimizedOrdinalComparer.cs" Condition=" $(TargetFramework.StartsWith('net4')) Or '$(TargetFramework)' == 'netstandard2.0' " />
-    <Compile Remove="NullableAttributes.cs" />
-    <Compile Include="NullableAttributes.cs" Condition=" $(TargetFramework.StartsWith('net4')) Or '$(TargetFramework)' == 'netstandard2.0' " />
   </ItemGroup>
 
 </Project>
diff --git a/MimeKit/NullableAttributes.cs b/MimeKit/NullableAttributes.cs
index d9b5357aae..9c5771483d 100644
--- a/MimeKit/NullableAttributes.cs
+++ b/MimeKit/NullableAttributes.cs
@@ -25,6 +25,7 @@
 //
 
 namespace System.Diagnostics.CodeAnalysis {
+#if NETFRAMEWORK || NETSTANDARD2_0
 	[AttributeUsage (AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property, Inherited = false)]
 	sealed class AllowNullAttribute : Attribute
 	{
@@ -65,8 +66,32 @@ sealed class MaybeNullWhenAttribute : Attribute
 		public bool ReturnValue { get; }
 	}
 
+	[AttributeUsage (AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, Inherited = false)]
+	sealed class NotNullAttribute : Attribute
+	{
+		public NotNullAttribute () { }
+	}
+
+	[AttributeUsage (AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, AllowMultiple = true, Inherited = false)]
+	sealed class NotNullIfNotNullAttribute : Attribute
+	{
+		public NotNullIfNotNullAttribute (string parameterName) => ParameterName = parameterName;
+
+		public string ParameterName { get; }
+	}
+
+	[AttributeUsage (AttributeTargets.Parameter, Inherited = false)]
+	sealed class NotNullWhenAttribute : Attribute
+	{
+		public NotNullWhenAttribute (bool returnValue) => ReturnValue = returnValue;
+
+		public bool ReturnValue { get; }
+	}
+#endif
+
+#if NETFRAMEWORK || NETSTANDARD2_0 || NETSTANDARD2_1
 	[AttributeUsage (AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.ReturnValue, AllowMultiple = true, Inherited = false)]
-	sealed class MemberNotNullAttribute : Attribute
+	public sealed class MemberNotNullAttribute : Attribute
 	{
 		public MemberNotNullAttribute (string member) => Members = new string[] { member };
 
@@ -94,26 +119,5 @@ public MemberNotNullWhenAttribute (bool returnValue, string[] members)
 
 		public bool ReturnValue { get; }
 	}
-
-	[AttributeUsage (AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, Inherited = false)]
-	sealed class NotNullAttribute : Attribute
-	{
-		public NotNullAttribute () { }
-	}
-
-	[AttributeUsage (AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, AllowMultiple = true, Inherited = false)]
-	sealed class NotNullIfNotNullAttribute : Attribute
-	{
-		public NotNullIfNotNullAttribute (string parameterName) => ParameterName = parameterName;
-
-		public string ParameterName { get; }
-	}
-
-	[AttributeUsage (AttributeTargets.Parameter, Inherited = false)]
-	sealed class NotNullWhenAttribute : Attribute
-	{
-		public NotNullWhenAttribute (bool returnValue) => ReturnValue = returnValue;
-
-		public bool ReturnValue { get; }
-	}
+#endif
 }