From b85d1ba65af5d929eccd5f6695a9a9e23ce9f6ab Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Wed, 5 Oct 2022 21:13:43 +0200
Subject: [PATCH] Fix #2771: Allow MetadataTypeDefinition.DefaultMemberName to
 return null if DefaultMemberAttribute is not present.

---
 .../TypeSystem/Implementation/MetadataTypeDefinition.cs    | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataTypeDefinition.cs b/ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataTypeDefinition.cs
index 560683e55..8417e33b0 100644
--- a/ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataTypeDefinition.cs
+++ b/ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataTypeDefinition.cs
@@ -58,6 +58,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		IEvent[] events;
 		IMethod[] methods;
 		List<IType> directBaseTypes;
+		bool defaultMemberNameInitialized;
 		string defaultMemberName;
 
 		internal MetadataTypeDefinition(MetadataModule module, TypeDefinitionHandle handle)
@@ -459,7 +460,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public string DefaultMemberName {
 			get {
 				string defaultMemberName = LazyInit.VolatileRead(ref this.defaultMemberName);
-				if (defaultMemberName != null)
+				if (defaultMemberName != null || defaultMemberNameInitialized)
 					return defaultMemberName;
 				var metadata = module.metadata;
 				var typeDefinition = metadata.GetTypeDefinition(handle);
@@ -475,7 +476,9 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 						break;
 					}
 				}
-				return LazyInit.GetOrSet(ref this.defaultMemberName, defaultMemberName ?? "Item");
+				defaultMemberName = LazyInit.GetOrSet(ref this.defaultMemberName, defaultMemberName);
+				defaultMemberNameInitialized = true;
+				return defaultMemberName;
 			}
 		}
 		#endregion