Implement workaround for #1961

ICSharpCode.Decompiler/CSharp/StatementBuilder.cs

@@ -992,6 +992,12 @@ namespace ICSharpCode.Decompiler.CSharp
 				stmt.Parameters.AddRange(exprBuilder.MakeParameters(function.Parameters, function));
 				stmt.ReturnType = exprBuilder.ConvertType(function.Method.ReturnType);
 				stmt.Body = nestedBuilder.ConvertAsBlock(function.Body);
+
+				Comment prev = null;
+				foreach (string warning in function.Warnings) {
+					stmt.Body.InsertChildAfter(prev, prev = new Comment(warning), Roles.Comment);
+				}
+
 				if (function.Method.TypeParameters.Count > 0) {
 					var astBuilder = exprBuilder.astBuilder;
 					if (astBuilder.ShowTypeParameters) {

ICSharpCode.Decompiler/IL/Transforms/DelegateConstruction.cs

@@ -31,11 +31,16 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 	{
 		ILTransformContext context;
 		ITypeResolveContext decompilationContext;
+		readonly Stack<MethodDefinitionHandle> activeMethods = new Stack<MethodDefinitionHandle>();
 		
 		void IILTransform.Run(ILFunction function, ILTransformContext context)
 		{
 			if (!context.Settings.AnonymousMethods)
 				return;
+			var prevContext = this.context;
+			var prevDecompilationContext = this.decompilationContext;
+			try {
+				activeMethods.Push((MethodDefinitionHandle)function.Method.MetadataToken);
 				this.context = context;
 				this.decompilationContext = new SimpleTypeResolveContext(function.Method);
 				var cancellationToken = context.CancellationToken;
@@ -58,6 +63,11 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 						context.StepEndGroup();
 					}
 				}
+			} finally {
+				this.context = prevContext;
+				this.decompilationContext = prevDecompilationContext;
+				activeMethods.Pop();
+			}
 		}
 
 		internal static bool IsDelegateConstruction(NewObj inst, bool allowTransformed = false)
@@ -131,6 +141,11 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			if (LocalFunctionDecompiler.IsLocalFunctionMethod(targetMethod, context))
 				return null;
 			target = value.Arguments[0];
+			var handle = (MethodDefinitionHandle)targetMethod.MetadataToken;
+			if (activeMethods.Contains(handle)) {
+				this.context.Function.Warnings.Add(" Found self-referencing delegate construction. Abort transformation to avoid stack overflow.");
+				return null;
+			}
 			var methodDefinition = context.PEFile.Metadata.GetMethodDefinition((MethodDefinitionHandle)targetMethod.MetadataToken);
 			if (!methodDefinition.HasBody())
 				return null;
@@ -157,7 +172,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			function.AcceptVisitor(new ReplaceDelegateTargetVisitor(target, function.Variables.SingleOrDefault(v => v.Index == -1 && v.Kind == VariableKind.Parameter)));
 			// handle nested lambdas
 			nestedContext.StepStartGroup("DelegateConstruction (nested lambdas)", function);
-			((IILTransform)new DelegateConstruction()).Run(function, nestedContext);
+			((IILTransform)this).Run(function, nestedContext);
 			nestedContext.StepEndGroup();
 			function.AddILRange(target);
 			function.AddILRange(value);