From 2bcafb8c4f3d7d7ae4b8bcb53123332c139a3a71 Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Tue, 7 Aug 2018 17:46:41 +0200
Subject: [PATCH] Fix #1247: Empty destructors are not decompiled correctly

---
 .../Transforms/PatternStatementTransform.cs   | 35 ++++++++++++++-----
 .../Implementation/MetadataMethod.cs          |  2 +-
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/ICSharpCode.Decompiler/CSharp/Transforms/PatternStatementTransform.cs b/ICSharpCode.Decompiler/CSharp/Transforms/PatternStatementTransform.cs
index f2efa6d3c..e7f0bfe3c 100644
--- a/ICSharpCode.Decompiler/CSharp/Transforms/PatternStatementTransform.cs
+++ b/ICSharpCode.Decompiler/CSharp/Transforms/PatternStatementTransform.cs
@@ -121,7 +121,12 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 		{
 			return TransformDestructor(methodDeclaration) ?? base.VisitMethodDeclaration(methodDeclaration);
 		}
-		
+
+		public override AstNode VisitDestructorDeclaration(DestructorDeclaration destructorDeclaration)
+		{
+			return TransformDestructorBody(destructorDeclaration) ?? base.VisitDestructorDeclaration(destructorDeclaration);
+		}
+
 		public override AstNode VisitTryCatchStatement(TryCatchStatement tryCatchStatement)
 		{
 			return TransformTryCatchFinally(tryCatchStatement) ?? base.VisitTryCatchStatement(tryCatchStatement);
@@ -812,16 +817,18 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			Modifiers = Modifiers.Any,
 			ReturnType = new PrimitiveType("void"),
 			Name = "Finalize",
-			Body = new BlockStatement {
-				new TryCatchStatement {
-					TryBlock = new AnyNode("body"),
-					FinallyBlock = new BlockStatement {
-						new InvocationExpression(new MemberReferenceExpression(new BaseReferenceExpression(), "Finalize"))
-					}
+			Body = destructorBodyPattern
+		};
+
+		static readonly BlockStatement destructorBodyPattern = new BlockStatement {
+			new TryCatchStatement {
+				TryBlock = new AnyNode("body"),
+				FinallyBlock = new BlockStatement {
+					new InvocationExpression(new MemberReferenceExpression(new BaseReferenceExpression(), "Finalize"))
 				}
 			}
 		};
-		
+
 		DestructorDeclaration TransformDestructor(MethodDeclaration methodDef)
 		{
 			Match m = destructorPattern.Match(methodDef);
@@ -837,8 +844,18 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			}
 			return null;
 		}
+
+		DestructorDeclaration TransformDestructorBody(DestructorDeclaration dtorDef)
+		{
+			Match m = destructorBodyPattern.Match(dtorDef.Body);
+			if (m.Success) {
+				dtorDef.Body = m.Get<BlockStatement>("body").Single().Detach();
+				return dtorDef;
+			}
+			return null;
+		}
 		#endregion
-		
+
 		#region Try-Catch-Finally
 		static readonly TryCatchStatement tryCatchFinallyPattern = new TryCatchStatement {
 			TryBlock = new BlockStatement {
diff --git a/ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataMethod.cs b/ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataMethod.cs
index 1fa81dbdd..3b5571a10 100644
--- a/ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataMethod.cs
+++ b/ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataMethod.cs
@@ -72,7 +72,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 					this.symbolKind = SymbolKind.Operator;
 			} else if ((attributes & finalizerAttributes) == finalizerAttributes) {
 				string name = this.Name;
-				if (name == "Finalize") {
+				if (name == "Finalize" && Parameters.Count == 0) {
 					this.symbolKind = SymbolKind.Destructor;
 				}
 			}