From 45efc732a726e4efe82930510492bd73b23e2e28 Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Thu, 20 Nov 2025 13:25:39 +0100
Subject: [PATCH] #3614: Use correct number of type arguments when adding type
 annotations to generic types with nested types.

---
 .../CSharp/Syntax/TypeSystemAstBuilder.cs                 | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/ICSharpCode.Decompiler/CSharp/Syntax/TypeSystemAstBuilder.cs b/ICSharpCode.Decompiler/CSharp/Syntax/TypeSystemAstBuilder.cs
index 58fd10c83..dae49f6d0 100644
--- a/ICSharpCode.Decompiler/CSharp/Syntax/TypeSystemAstBuilder.cs
+++ b/ICSharpCode.Decompiler/CSharp/Syntax/TypeSystemAstBuilder.cs
@@ -546,7 +546,13 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			{
 				// Handle nested types
 				result.Target = ConvertTypeHelper(genericType.DeclaringType, typeArguments);
-				AddTypeAnnotation(result.Target, genericType.DeclaringType);
+				// Use correct number of type arguments on the declaring type
+				var declaringType = genericType.DeclaringType;
+				if (outerTypeParameterCount > 0)
+				{
+					declaringType = new ParameterizedType(genericType.DeclaringType, typeArguments.Take(outerTypeParameterCount));
+				}
+				AddTypeAnnotation(result.Target, declaringType);
 			}
 			else
 			{