Describe this repository

Roslyn spills the receiver of an initializer assignment that precedes an
await into a hoisted temporary, so the clone of a with expression (and the
object of an object initializer) reaches the initializer transform through
a copy it rejects. Only copies between two hoisted compiler temporaries are
inlined: folding copies of hoisted user locals as well would turn a user's
local into an initializer.

ICSharpCode.Decompiler.Tests/TestCases/Correctness/NullPropagation.cs

@@ -0,0 +1,85 @@
+using System;
+
+namespace ICSharpCode.Decompiler.Tests.TestCases.Correctness
+{
+	class NullPropagation
+	{
+		static void Main()
+		{
+			new NullPropagation().TestNotCoalescing();
+			new NullPropagation().TestNullableBoolInChain();
+#if CS72
+			new NullPropagation().TestRefStructNotCoalescing();
+#endif
+		}
+
+		class MyClass
+		{
+			public string Text;
+			public bool? Flag;
+		}
+
+		void TestNotCoalescing()
+		{
+			Console.WriteLine("TestNotCoalescing:");
+			Console.WriteLine(NotCoalescing(null));
+			Console.WriteLine(NotCoalescing(new MyClass()));
+		}
+
+		string NotCoalescing(MyClass c)
+		{
+			return c != null ? c.Text : "Hello";
+		}
+
+		void TestNullableBoolInChain()
+		{
+			Console.WriteLine("TestNullableBoolInChain:");
+			foreach (MyClass c in new[] { null, new MyClass(), new MyClass { Flag = false }, new MyClass { Flag = true } })
+			{
+				Console.WriteLine(EqualsTrue(c));
+				Console.WriteLine(GetValueOrDefaultToString(c) ?? "<null>");
+			}
+		}
+
+		bool EqualsTrue(MyClass c)
+		{
+			return c?.Flag == true;
+		}
+
+		string GetValueOrDefaultToString(MyClass c)
+		{
+			return c?.Flag.GetValueOrDefault().ToString();
+		}
+
+#if CS72
+		ref struct ByRefLikeStruct
+		{
+			public int Value;
+		}
+
+		class RefStructHolder
+		{
+			public ByRefLikeStruct Get()
+			{
+				ByRefLikeStruct result = default(ByRefLikeStruct);
+				result.Value = 42;
+				return result;
+			}
+		}
+
+		void TestRefStructNotCoalescing()
+		{
+			Console.WriteLine("TestRefStructNotCoalescing:");
+			Console.WriteLine(RefStructNotCoalescing(null).Value);
+			Console.WriteLine(RefStructNotCoalescing(new RefStructHolder()).Value);
+		}
+
+		// A by-ref-like return type cannot be turned into a ?. / ?? null-propagation: a ref struct
+		// cannot be wrapped in Nullable<T>, so that form does not compile.
+		ByRefLikeStruct RefStructNotCoalescing(RefStructHolder holder)
+		{
+			return holder != null ? holder.Get() : default(ByRefLikeStruct);
+		}
+#endif
+	}
+}

ICSharpCode.Decompiler.Tests/TestCases/Pretty/AsyncAwaitPatterns.cs

@@ -0,0 +1,710 @@
+// Copyright (c) 2026 Siegfried Pammer
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+// An await shape that still decompiles to code that does not compile is tracked as #4017 (type
+// parameter with an interface constraint); it is absent here because it has no correct output to
+// pin yet.
+
+#pragma warning disable 1998
+using System;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Threading.Tasks;
+
+namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty.AsyncAwait
+{
+	public class AwaitableContainer
+	{
+		public class NestedAwaitable
+		{
+			public TaskAwaiter GetAwaiter()
+			{
+#if CS71
+				return default;
+#else
+				return default(TaskAwaiter);
+#endif
+			}
+		}
+	}
+
+	/// <summary>
+	/// The context the await sits in: how the translated expression has to be parenthesized, and
+	/// where the async state machine splits the surrounding statement.
+	/// </summary>
+	public class AwaitContexts
+	{
+#if CS80 && !NET40
+		private sealed class AsyncDisposable : IAsyncDisposable
+		{
+			public ValueTask DisposeAsync()
+			{
+				return default;
+			}
+		}
+#endif
+
+		private static Task<int> Get()
+		{
+			return Task.FromResult(1);
+		}
+
+		private static Task<string> GetString()
+		{
+			return Task.FromResult("s");
+		}
+
+		private static Task<Exception> GetException()
+		{
+			return Task.FromResult(new Exception());
+		}
+
+		public async Task Statement()
+		{
+			await Get();
+		}
+
+		public async Task Argument()
+		{
+			Console.WriteLine(await Get());
+		}
+
+#if ROSLYN2 || OPT
+		public async Task BinaryOperator()
+		{
+			Console.WriteLine(await Get() + await Get());
+		}
+#endif
+
+#if ROSLYN2 || OPT
+		public async Task UnaryOperator()
+		{
+			Console.WriteLine(-(await Get()));
+		}
+#endif
+
+#if ROSLYN2 || OPT
+		public async Task MemberAccessOnResult()
+		{
+			Console.WriteLine((await GetString()).Length);
+		}
+#endif
+
+#if ROSLYN2 || OPT
+		public async Task IndexerOnResult()
+		{
+			Console.WriteLine((await GetString())[0]);
+		}
+#endif
+
+#if ROSLYN2 || OPT
+		public async Task CoalesceOnResult()
+		{
+			Console.WriteLine((await GetString()) ?? "null");
+		}
+#endif
+
+		public async Task ThrowAwaitedException()
+		{
+			throw await GetException();
+		}
+
+#if ROSLYN2 || OPT
+		public async Task Checked()
+		{
+			Console.WriteLine(checked(await Get() + 1));
+		}
+#endif
+
+#if CS60
+		public async Task TryFinally()
+		{
+			try
+			{
+				await Get();
+			}
+			finally
+			{
+				await Get();
+			}
+		}
+#endif
+
+		public async Task Using()
+		{
+			using (new Disposable())
+			{
+				await Get();
+			}
+		}
+
+#if CS60
+		public async Task ConditionalAccessOnResult()
+		{
+#if ROSLYN2 || OPT
+			Console.WriteLine((await GetString())?.Length);
+#else
+			object value = (await GetString())?.Length;
+			Console.WriteLine(value);
+#endif
+		}
+
+		public async Task CatchWithFilter()
+		{
+			try
+			{
+				await Get();
+			}
+			catch (Exception ex) when (ex.Message.Length > 2)
+			{
+				await Get();
+			}
+		}
+#endif
+
+#if CS70 && !NET40
+		public async Task AwaitInTupleLiteral()
+		{
+			Console.WriteLine((await Get(), await GetString()));
+		}
+#endif
+
+#if CS80 && !NET40
+		public async Task AwaitUsing()
+		{
+			await using (new AsyncDisposable())
+			{
+				await Get();
+			}
+		}
+
+		public async Task AwaitForeach(IAsyncEnumerable<int> source)
+		{
+			await foreach (int item in source)
+			{
+				Console.WriteLine(item);
+			}
+		}
+
+		public async Task AwaitForeachConfigured(IAsyncEnumerable<int> source)
+		{
+			await foreach (int item in source.ConfigureAwait(continueOnCapturedContext: false))
+			{
+				Console.WriteLine(item);
+			}
+		}
+
+		public async IAsyncEnumerable<int> AsyncIterator()
+		{
+			yield return await Get();
+			await Task.Yield();
+			yield return 2;
+		}
+
+		public async IAsyncEnumerable<int> AsyncIteratorWithFinally()
+		{
+			try
+			{
+				yield return await Get();
+			}
+			finally
+			{
+				Console.WriteLine("cleanup");
+			}
+		}
+
+		public async Task LocalFunction()
+		{
+			Console.WriteLine(await Local());
+			static async Task<int> Local()
+			{
+				return await Get();
+			}
+		}
+#endif
+
+#if ROSLYN2 || OPT
+		public async Task AwaitInGenericMethod<T>(Task<T> task)
+		{
+			Console.WriteLine(await task);
+		}
+#endif
+	}
+
+	public static class AwaiterExtensions
+	{
+		public static TaskAwaiter GetAwaiter(this IAwaitableMarker marker)
+		{
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter);
+#endif
+		}
+
+		public static TaskAwaiter GetAwaiter(this int millisecondsDelay)
+		{
+			return Task.Delay(millisecondsDelay).GetAwaiter();
+		}
+
+		public static TaskAwaiter GetAwaiter(this Action action)
+		{
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter);
+#endif
+		}
+
+		public static TaskAwaiter<T[]> GetAwaiter<T>(this IEnumerable<Task<T>> tasks)
+		{
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter<T[]>);
+#endif
+		}
+
+#if CS70 && !NET40
+		public static TaskAwaiter<T> GetAwaiter<T>(this (Task<T>, string) taggedTask)
+		{
+			return taggedTask.Item1.GetAwaiter();
+		}
+#endif
+
+#if CS72
+		public static TaskAwaiter GetAwaiter(this in ByRefReceiver receiver)
+		{
+			return receiver.Self();
+		}
+#endif
+	}
+
+	/// <summary>
+	/// The operand side: the shape of the expression the await is applied to.
+	/// </summary>
+	public class AwaitOperands
+	{
+		private Task<int> taskField;
+
+		private StructAwaitable structField;
+
+		private readonly StructAwaitable readonlyStructField;
+
+		private Task<int> Property {
+			get {
+				Console.WriteLine("get_Property");
+				return taskField;
+			}
+		}
+
+		private Task<int> this[int index] {
+			get {
+				Console.WriteLine("get_Item");
+				return taskField;
+			}
+		}
+
+		private static Task<int> Get()
+		{
+			return Task.FromResult(1);
+		}
+
+		public async Task DefaultOfStruct()
+		{
+			await default(StructAwaitable);
+		}
+
+		public async Task Ternary(bool condition, Task first, Task second)
+		{
+			await (condition ? first : second);
+		}
+
+		public async Task Coalesce(Task first, Task second)
+		{
+			await (first ?? second);
+		}
+
+#if CS60
+		public async Task NullConditional(List<Task> tasks)
+		{
+			await (tasks?[0]);
+		}
+#endif
+
+		public async Task Cast(object obj)
+		{
+			await (Task)obj;
+		}
+
+		/// <summary>
+		/// A null literal has no type, so the cast is what makes the operand awaitable. Note that
+		/// <c>default(Task)</c> compiles to the same `ldnull` and therefore decompiles to this same
+		/// cast; the two are indistinguishable in IL.
+		/// </summary>
+		public async Task NullLiteral()
+		{
+			await (Task)null;
+		}
+
+		public async Task AsOperator(object obj)
+		{
+			await (obj as Task);
+		}
+
+		public async Task FieldAccess()
+		{
+			Console.WriteLine(await taskField);
+		}
+
+		public async Task PropertyAccess()
+		{
+			Console.WriteLine(await Property);
+		}
+
+		public async Task IndexerAccess()
+		{
+			Console.WriteLine(await this[0]);
+		}
+
+		public async Task StructField()
+		{
+			await structField;
+		}
+
+		public async Task ReadOnlyStructField()
+		{
+			await readonlyStructField;
+		}
+
+		public async Task StructArrayElement(StructAwaitable[] awaitables)
+		{
+			await awaitables[0];
+		}
+
+		public async Task MethodCall()
+		{
+			Console.WriteLine(await Get());
+		}
+
+		public async Task DelegateInvocation(Func<Task<int>> factory)
+		{
+			Console.WriteLine(await factory());
+		}
+
+		public async Task ArrayElement(Task<int>[] tasks)
+		{
+			Console.WriteLine(await tasks[0]);
+		}
+
+		public async Task TernaryOfTasks(bool condition)
+		{
+			Console.WriteLine(await (condition ? Get() : Get()));
+		}
+	}
+
+	/// <summary>
+	/// The receiver ("expected type") side of ExpressionBuilder.VisitAwait: the awaited expression
+	/// is converted to the declaring type of the resolved GetAwaiter, or to its first parameter
+	/// type when GetAwaiter is an extension method.
+	/// </summary>
+	public class AwaitReceivers
+	{
+		public async Task InstanceAwaiterOnSelf(ClassAwaitable awaitable)
+		{
+			await awaitable;
+		}
+
+		public async Task AwaiterInheritedFromBaseClass(DerivedAwaitable awaitable)
+		{
+			await awaitable;
+		}
+
+		public async Task AwaiterThroughInterface(IAwaitable awaitable)
+		{
+			await awaitable;
+		}
+
+		public async Task AwaiterThroughBaseInterface(IDerivedAwaitable awaitable)
+		{
+			await awaitable;
+		}
+
+		/// <summary>
+		/// The cast carries the operand to the interface that declares GetAwaiter; without it the
+		/// explicit implementation is not accessible. A conversion that is merely implicit must not
+		/// be dropped here, even though a boxing conversion exists.
+		/// </summary>
+		public async Task ExplicitInterfaceImplementationOnStruct(ExplicitStructAwaitable awaitable)
+		{
+			await (IAwaitable)awaitable;
+		}
+
+		/// <summary>
+		/// The same shape on a class, i.e. it is not specific to the boxing conversion.
+		/// </summary>
+		public async Task ExplicitInterfaceImplementationOnClass(ExplicitClassAwaitable awaitable)
+		{
+			await (IAwaitable)awaitable;
+		}
+
+		/// <summary>
+		/// The await pattern does not apply user-defined conversions, so the cast that invokes
+		/// op_Implicit has to survive.
+		/// </summary>
+		public async Task UserDefinedConversionToAwaitable(ConvertsToAwaitable awaitable)
+		{
+			await (ClassAwaitable)awaitable;
+		}
+
+		public async Task ExtensionAwaiterOnClass(MarkerClass marker)
+		{
+			await marker;
+		}
+
+		public async Task ExtensionAwaiterOnStruct(MarkerStruct marker)
+		{
+			await marker;
+		}
+
+		public async Task ExtensionAwaiterOnPrimitive()
+		{
+			await 100;
+		}
+
+		public async Task ExtensionAwaiterOnDelegate(Action action)
+		{
+			await action;
+		}
+
+#if CS72
+		/// <summary>
+		/// An extension GetAwaiter taking its receiver by 'in' makes the expected type a
+		/// ByReferenceType. Stripping the 'ref' must not leave a conversion that reaches the
+		/// managed reference back through a pointer.
+		/// </summary>
+		public async Task InReceiverExtensionAwaiter(ByRefReceiver receiver)
+		{
+			await receiver;
+		}
+#endif
+
+#if ROSLYN2
+		public async Task ExtensionAwaiterOverTaskArray(Task<int>[] tasks)
+		{
+			Console.WriteLine((await tasks)[0]);
+		}
+#endif
+
+#if ROSLYN2
+		public async Task ExtensionAwaiterOverTaskList(List<Task<int>> tasks)
+		{
+			Console.WriteLine((await tasks)[0]);
+		}
+#endif
+
+		public async Task GenericAwaitableType(GenericAwaitable<string> awaitable)
+		{
+			Console.WriteLine(await awaitable);
+		}
+
+		public async Task NestedAwaitableType(AwaitableContainer.NestedAwaitable awaitable)
+		{
+			await awaitable;
+		}
+
+		public async Task TypeParameterWithClassConstraint<T>(T awaitable) where T : ClassAwaitable
+		{
+			await awaitable;
+		}
+
+		public async Task TypeParameterWithStructConstraint<T>(T awaitable) where T : struct, IAwaitable
+		{
+			await awaitable;
+		}
+
+		public async Task ConfiguredTaskAwaitable(Task<int> task)
+		{
+#if ROSLYN2
+			Console.WriteLine(await task.ConfigureAwait(continueOnCapturedContext: false));
+#else
+			Console.WriteLine(await task.ConfigureAwait(false));
+#endif
+		}
+
+#if CS70 && !NET40
+		public async Task ExtensionAwaiterOnTuple(Task<int> task)
+		{
+			Console.WriteLine(await (task, "tag"));
+		}
+#endif
+
+#if CS80 && !NET40
+		public async Task ValueTaskAwaitable(ValueTask<int> task)
+		{
+			Console.WriteLine(await task);
+		}
+
+		public async Task ConfiguredValueTaskAwaitable(ValueTask<int> task)
+		{
+			Console.WriteLine(await task.ConfigureAwait(continueOnCapturedContext: false));
+		}
+#endif
+
+#if NET80
+		public async Task ConfigureAwaitWithOptions(Task task)
+		{
+			await task.ConfigureAwait(ConfigureAwaitOptions.SuppressThrowing);
+		}
+#endif
+
+		public async Task AwaitOfAwait(Task<Task<int>> task)
+		{
+			Console.WriteLine(await (await task));
+		}
+	}
+
+#if CS72
+	public struct ByRefReceiver
+	{
+		public long A;
+
+		public long B;
+
+		public TaskAwaiter Self()
+		{
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter);
+#endif
+		}
+	}
+#endif
+
+	public class ClassAwaitable : IAwaitable
+	{
+		public TaskAwaiter GetAwaiter()
+		{
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter);
+#endif
+		}
+	}
+
+	public class ConvertsToAwaitable
+	{
+		public static implicit operator ClassAwaitable(ConvertsToAwaitable value)
+		{
+			return new ClassAwaitable();
+		}
+	}
+
+	public class DerivedAwaitable : ClassAwaitable
+	{
+	}
+
+	public class Disposable : IDisposable
+	{
+		public void Dispose()
+		{
+		}
+	}
+
+	public class ExplicitClassAwaitable : IAwaitable
+	{
+		TaskAwaiter IAwaitable.GetAwaiter()
+		{
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter);
+#endif
+		}
+	}
+
+	[StructLayout(LayoutKind.Sequential, Size = 1)]
+	public struct ExplicitStructAwaitable : IAwaitable
+	{
+		TaskAwaiter IAwaitable.GetAwaiter()
+		{
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter);
+#endif
+		}
+	}
+
+	public class GenericAwaitable<T>
+	{
+		public TaskAwaiter<T> GetAwaiter()
+		{
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter<T>);
+#endif
+		}
+	}
+
+	public interface IAwaitable
+	{
+		TaskAwaiter GetAwaiter();
+	}
+
+	public interface IAwaitableMarker
+	{
+	}
+
+	public interface IBaseAwaitable
+	{
+		TaskAwaiter GetAwaiter();
+	}
+
+	public interface IDerivedAwaitable : IBaseAwaitable
+	{
+	}
+
+	public class MarkerClass : IAwaitableMarker
+	{
+	}
+
+	[StructLayout(LayoutKind.Sequential, Size = 1)]
+	public struct MarkerStruct : IAwaitableMarker
+	{
+	}
+
+	public struct StructAwaitable : IAwaitable
+	{
+		public int Counter;
+
+		public TaskAwaiter GetAwaiter()
+		{
+			Counter++;
+#if CS71
+			return default;
+#else
+			return default(TaskAwaiter);
+#endif
+		}
+	}
+}

ICSharpCode.Decompiler.Tests/TestCases/Pretty/NativeInts.cs

@@ -254,5 +254,10 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 			// Explicit `unchecked` is necessary when casting oversized constant to nuint
 			return unchecked((nuint)9123123123123uL);
 		}
+
+		public nint ConditionalWithMixedBranchTypes(bool b, int i, nuint x, nint y)
+		{
+			return (b ? ((nint)i) : ((nint)x)) - y;
+		}
 	}
 }

ICSharpCode.Decompiler.Tests/TestCases/Pretty/NullPropagation.cs

@@ -0,0 +1,395 @@
+// Copyright (c) 2018 Daniel Grunwald
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
+{
+	internal class NullPropagation
+	{
+		private class MyClass
+		{
+			public int IntVal;
+			public readonly int ReadonlyIntVal;
+			public MyStruct StructField;
+			public readonly MyStruct ReadonlyStructField;
+			public string Text;
+			public MyClass Field;
+			public bool? NullableBool;
+			public MyClass Property { get; set; }
+			public MyClass this[int index] => null;
+			public MyClass Method(int arg)
+			{
+				return null;
+			}
+
+			public bool GetBool()
+			{
+				return false;
+			}
+
+			public void Done()
+			{
+			}
+		}
+
+		private struct MyStruct
+		{
+			public int IntVal;
+			public readonly int ReadonlyIntVal;
+			public MyClass Field;
+			public MyStruct? Property1 => null;
+#if CS71
+			public MyStruct Property2 => default;
+#else
+			public MyStruct Property2 => default(MyStruct);
+#endif
+			public MyStruct? this[int index] => null;
+			public MyStruct? Method1(int arg)
+			{
+				return null;
+			}
+			public MyStruct Method2(int arg)
+			{
+#if CS71
+				return default;
+#else
+				return default(MyStruct);
+#endif
+			}
+
+			public bool GetBool()
+			{
+				return false;
+			}
+
+			public void Done()
+			{
+			}
+		}
+
+		private class Container<T1, T2>
+		{
+			public GenericStruct<T1, T2> Other;
+		}
+
+		private struct GenericStruct<T1, T2>
+		{
+			public T1 Field1;
+			public T2 Field2;
+			public Container<T1, T2> Other;
+
+			public override string ToString()
+			{
+				return "(" + Field1?.ToString() + ", " + Field2?.ToString() + ")";
+			}
+
+			public int? GetTextLength()
+			{
+				return Field1?.ToString().Length + Field2?.ToString().Length + 4;
+			}
+
+			public string Chain1()
+			{
+				return Other?.Other.Other?.Other.Field1?.ToString();
+			}
+
+			public string Chain2()
+			{
+				return Other?.Other.Other?.Other.Field1?.ToString()?.GetType().Name;
+			}
+
+			public int? Test2()
+			{
+				return Field1?.ToString().Length ?? 42;
+			}
+
+			public int? GetTextLengthNRE()
+			{
+				return (Field1?.ToString()).Length;
+			}
+		}
+
+		public interface ITest
+		{
+			int Int();
+			ITest Next();
+		}
+
+		private int GetInt()
+		{
+			return 9;
+		}
+
+		private string GetString()
+		{
+			return null;
+		}
+
+		private MyClass GetMyClass()
+		{
+			return null;
+		}
+
+		private MyStruct? GetMyStruct()
+		{
+			return null;
+		}
+
+		public string Substring()
+		{
+			return GetString()?.Substring(GetInt());
+		}
+
+		public void CallSubstringAndIgnoreResult()
+		{
+			GetString()?.Substring(GetInt());
+		}
+
+		private void Use<T>(T t)
+		{
+		}
+
+		public void CallDone()
+		{
+			GetMyClass()?.Done();
+			GetMyClass()?.Field?.Done();
+			GetMyClass()?.Field.Done();
+			GetMyClass()?.Property?.Done();
+			GetMyClass()?.Property.Done();
+			GetMyClass()?.Method(GetInt())?.Done();
+			GetMyClass()?.Method(GetInt()).Done();
+			GetMyClass()?[GetInt()]?.Done();
+			GetMyClass()?[GetInt()].Done();
+		}
+
+		public void CallGetBool()
+		{
+			GetMyClass()?.GetBool();
+			GetMyClass()?.Field?.GetBool();
+			GetMyClass()?.Field.GetBool();
+			GetMyClass()?.Property?.GetBool();
+			GetMyClass()?.Property.GetBool();
+			GetMyClass()?.Method(GetInt())?.GetBool();
+			GetMyClass()?.Method(GetInt()).GetBool();
+			GetMyClass()?[GetInt()]?.GetBool();
+			GetMyClass()?[GetInt()].GetBool();
+		}
+
+		public void CallDoneStruct()
+		{
+			GetMyStruct()?.Done();
+			GetMyStruct()?.Field?.Done();
+			GetMyStruct()?.Field.Done();
+			GetMyStruct()?.Property1?.Done();
+			GetMyStruct()?.Property2.Done();
+			GetMyStruct()?.Method1(GetInt())?.Done();
+			GetMyStruct()?.Method2(GetInt()).Done();
+			GetMyStruct()?[GetInt()]?.Done();
+		}
+
+		public void CallGetBoolStruct()
+		{
+			GetMyStruct()?.GetBool();
+			GetMyStruct()?.Field?.GetBool();
+			GetMyStruct()?.Field.GetBool();
+			GetMyStruct()?.Property1?.GetBool();
+			GetMyStruct()?.Property2.GetBool();
+			GetMyStruct()?.Method1(GetInt())?.GetBool();
+			GetMyStruct()?.Method2(GetInt()).GetBool();
+			GetMyStruct()?[GetInt()]?.GetBool();
+		}
+
+		public void RequiredParentheses()
+		{
+			(GetMyClass()?.Field).Done();
+			(GetMyClass()?.Method(GetInt())).Done();
+			(GetMyStruct()?.Property2)?.Done();
+		}
+
+		public int?[] ChainsOnClass()
+		{
+			return new int?[9] {
+				GetMyClass()?.IntVal,
+				GetMyClass()?.Field.IntVal,
+				GetMyClass()?.Field?.IntVal,
+				GetMyClass()?.Property.IntVal,
+				GetMyClass()?.Property?.IntVal,
+				GetMyClass()?.Method(GetInt()).IntVal,
+				GetMyClass()?.Method(GetInt())?.IntVal,
+				GetMyClass()?[GetInt()].IntVal,
+				GetMyClass()?[GetInt()]?.IntVal
+			};
+		}
+
+		public int?[] ChainsStruct()
+		{
+			return new int?[8] {
+				GetMyStruct()?.IntVal,
+				GetMyStruct()?.Field.IntVal,
+				GetMyStruct()?.Field?.IntVal,
+				GetMyStruct()?.Property2.IntVal,
+				GetMyStruct()?.Property1?.IntVal,
+				GetMyStruct()?.Method2(GetInt()).IntVal,
+				GetMyStruct()?.Method1(GetInt())?.IntVal,
+				GetMyStruct()?[GetInt()]?.IntVal
+			};
+		}
+
+		public int CoalescingReturn()
+		{
+			return GetMyClass()?.IntVal ?? 1;
+		}
+
+		public void Coalescing()
+		{
+			Use(GetMyClass()?.IntVal ?? 1);
+		}
+
+		public void CoalescingString()
+		{
+			Use(GetMyClass()?.Text ?? "Hello");
+		}
+
+		public void CallOnValueTypeField()
+		{
+			Use(GetMyClass()?.IntVal.ToString());
+			Use(GetMyStruct()?.IntVal.ToString());
+			Use(GetMyClass()?.ReadonlyIntVal.ToString());
+			Use(GetMyStruct()?.ReadonlyIntVal.ToString());
+			GetMyClass()?.StructField.Done();
+			GetMyClass()?.ReadonlyStructField.Done();
+		}
+
+		public void InvokeDelegate(EventHandler eh)
+		{
+			eh?.Invoke(null, EventArgs.Empty);
+		}
+
+		public int? InvokeDelegate(Func<int> f)
+		{
+			return f?.Invoke();
+		}
+
+		private void NotNullPropagation(MyClass c)
+		{
+			// don't decompile this to "(c?.IntVal ?? 0) != 0"
+			if (c != null && c.IntVal != 0)
+			{
+				Console.WriteLine("non-zero");
+			}
+			if (c == null || c.IntVal == 0)
+			{
+				Console.WriteLine("null or zero");
+			}
+			Console.WriteLine("end of method");
+		}
+
+		private void Setter(MyClass c)
+		{
+			if (c != null)
+			{
+				c.IntVal = 1;
+			}
+			Console.WriteLine();
+			if (c != null)
+			{
+				c.Property = null;
+			}
+		}
+
+		private static int? GenericUnconstrainedInt<T>(T t) where T : ITest
+		{
+			return t?.Int();
+		}
+
+		private static int? GenericClassConstraintInt<T>(T t) where T : class, ITest
+		{
+			return t?.Int();
+		}
+
+		private static int? GenericStructConstraintInt<T>(T? t) where T : struct, ITest
+		{
+			return t?.Int();
+		}
+
+		private static int? GenericRefUnconstrainedInt<T>(ref T t) where T : ITest
+		{
+			return t?.Int();
+		}
+
+		private static int? GenericRefClassConstraintInt<T>(ref T t) where T : class, ITest
+		{
+			return t?.Int();
+		}
+
+		private static int? GenericRefStructConstraintInt<T>(ref T? t) where T : struct, ITest
+		{
+			return t?.Int();
+		}
+
+		public int? Issue1709(object obj)
+		{
+			return (obj as ICollection)?.Count + (obj as ICollection<int>)?.Count;
+		}
+
+		private static void Issue1689(List<byte[]> setsOfNumbers)
+		{
+			Console.WriteLine(setsOfNumbers?[0]?[1].ToString() == "2");
+			Console.WriteLine(setsOfNumbers?[1]?[1].ToString() == null);
+		}
+
+		private static byte[] GetBytes()
+		{
+			return null;
+		}
+
+		private static void ArrayLengthWithFallback()
+		{
+			Console.WriteLine(GetBytes()?.Length ?? 0);
+			Console.WriteLine(GetBytes()?.LongLength ?? 0);
+		}
+
+		private static dynamic DynamicNullProp(dynamic a)
+		{
+			return a?.b.c(1)?.d[10];
+		}
+
+		private static string Issue3181()
+		{
+#if EXPECTED_OUTPUT
+			return ((int?)null)?.ToString();
+#else
+			int? x = null;
+			return x?.ToString();
+#endif
+		}
+
+		private static bool Issue3702(MyClass c)
+		{
+			return c?.NullableBool.GetValueOrDefault() ?? false;
+		}
+
+		private static string Issue3702ToString(MyClass c)
+		{
+			return c?.NullableBool.GetValueOrDefault().ToString();
+		}
+	}
+}

ICSharpCode.Decompiler.Tests/TestCases/Pretty/Records.cs

@@ -0,0 +1,546 @@
+using System;
+#if CS100
+using System.Runtime.InteropServices;
+using System.Text;
+#endif
+using System.Threading.Tasks;
+
+namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
+{
+	internal class RecordClasses
+	{
+		public record Base(string A);
+
+		public record CopyCtor(string A)
+		{
+			protected CopyCtor(CopyCtor _)
+			{
+			}
+		}
+
+		public record Derived(int B) : Base(B.ToString());
+
+		public record BaseRecordWithObject(object Id);
+
+		public record DerivedRecordWithString : BaseRecordWithObject
+		{
+			public DerivedRecordWithString(string Id)
+				: base(Id)
+			{
+			}
+		}
+
+		public record Empty;
+
+		public record EmptyWithStaticField
+		{
+			public static readonly Empty X = new Empty();
+		}
+
+		public record Fields
+		{
+			public int A;
+			public double B = 1.0;
+			public object C;
+			public dynamic D;
+			public string S = "abc";
+		}
+
+		public record Interface(int B) : IRecord;
+
+		public interface IRecord
+		{
+		}
+
+		public record Pair<A, B>
+		{
+			public A First { get; init; }
+			public B Second { get; init; }
+		}
+
+		public record PairWithPrimaryCtor<A, B>(A First, B Second);
+
+		public record PrimaryCtor(int A, string B);
+		public record PrimaryCtorWithAttribute([RecordTest("param")][property: RecordTest("property")][field: RecordTest("field")] int a);
+		public record PrimaryCtorWithField(int A, string B)
+		{
+			public double C = 1.0;
+			public string D = A + B;
+		}
+		public record PrimaryCtorWithInParameter(in int A, in string B);
+		public record PrimaryCtorWithProperty(int A, string B)
+		{
+			public double C { get; init; } = 1.0;
+			public string D { get; } = A + B;
+		}
+
+		public record Properties
+		{
+			public int A { get; set; }
+			public int B { get; }
+			public int C => 43;
+			public object O { get; set; }
+			public string S { get; set; }
+			public dynamic D { get; set; }
+
+			public Properties()
+			{
+				B = 42;
+			}
+		}
+
+#if CS110
+		public record WithRequiredMembers
+		{
+			public required Type ServiceType { get; init; }
+
+			public required object ServiceKey { get; init; }
+		}
+#endif
+
+		[AttributeUsage(AttributeTargets.All)]
+		public class RecordTestAttribute : Attribute
+		{
+			public RecordTestAttribute(string name)
+			{
+			}
+		}
+
+		public sealed record Sealed(string A);
+
+		public sealed record SealedDerived(int B) : Base(B.ToString());
+
+		public class WithExpressionTests
+		{
+			public Fields Test(Fields input)
+			{
+				return input with {
+					A = 42,
+					B = 3.141,
+					C = input
+				};
+			}
+			public Fields Test2(Fields input)
+			{
+				return input with {
+					A = 42,
+					B = 3.141,
+					C = input with {
+						A = 43
+					}
+				};
+			}
+			public async Task<PrimaryCtor> WithAwait(PrimaryCtor input)
+			{
+				return input with {
+					A = await Task.FromResult(42)
+				};
+			}
+			public async Task<Fields> WithAwaitAfterConstant(Fields input)
+			{
+				return input with {
+					A = 42,
+					B = await Task.FromResult(3.141)
+				};
+			}
+		}
+
+		public abstract record WithNestedRecords
+		{
+			public record A : WithNestedRecords
+			{
+				public override string AbstractProp => "A";
+			}
+
+			public record B : WithNestedRecords
+			{
+				public override string AbstractProp => "B";
+
+				public int? Value { get; set; }
+			}
+
+			public record DerivedGeneric<T> : Pair<T, T?> where T : struct
+			{
+				public bool Flag;
+			}
+
+			public abstract string AbstractProp { get; }
+		}
+
+		public abstract record BaseRecord
+		{
+			public string Name { get; }
+			public object Value { get; }
+			public bool Encode { get; }
+
+			protected BaseRecord(string name, object value, bool encode)
+			{
+				Name = name;
+				Value = value;
+				Encode = encode;
+			}
+		}
+
+		public record DerivedRecord(string name, object value, bool encode = true) : BaseRecord(string.IsNullOrEmpty(name) ? "name" : name, value, encode);
+
+		public record DefaultValuesRecord() : DerivedRecord("default", 42, encode: false);
+
+		public record RecordWithProtectedMember(int Value)
+		{
+			protected int Double => Value * 2;
+		}
+
+		public record InheritedRecordWithAdditionalMember(int Value) : RecordWithProtectedMember(Value)
+		{
+			public int MoreData { get; set; }
+		}
+
+		public record InheritedRecordWithAdditionalParameter(int Value, int Value2) : RecordWithProtectedMember(Value);
+
+		public record BaseWithString(string S);
+
+		public record DerivedWithAdditionalInt(int I) : BaseWithString(I.ToString());
+
+		public record DerivedWithNoAdditionalProperty(string S) : BaseWithString(S);
+
+		public record DerivedWithAdditionalProperty(string S2) : BaseWithString(S2);
+
+		public record DerivedWithAdditionalPropertyDifferentAccessor(string S) : BaseWithString(S)
+		{
+			public string S2 { get; set; } = S;
+		}
+
+		public record MultipleCtorsChainedNoPrimaryCtor
+		{
+			public int A { get; init; }
+			public string B { get; init; }
+
+			public double C { get; init; }
+
+			public MultipleCtorsChainedNoPrimaryCtor(double c)
+			{
+				A = 0;
+				B = null;
+				C = c;
+			}
+
+			public MultipleCtorsChainedNoPrimaryCtor(int a)
+				: this(3.14)
+			{
+				A = a;
+			}
+
+			public MultipleCtorsChainedNoPrimaryCtor(string b)
+				: this(4.13)
+			{
+				B = b;
+			}
+		}
+
+		public record UnexpectedCodeInCtor
+		{
+			public int A { get; init; }
+			public string B { get; init; }
+
+			public UnexpectedCodeInCtor(int A, string B)
+			{
+				this.A = A;
+				this.B = B;
+				Console.WriteLine();
+			}
+
+			public UnexpectedCodeInCtor(int A)
+				: this(A, null)
+			{
+				this.A = A;
+			}
+		}
+
+		private record RecordWithMultipleInitializerAssignmentsInPrimaryCtor(string name, string? value, in object encode)
+		{
+			public string? Value { get; } = name;
+
+			public string Name { get; } = value;
+
+			private string? WebValue { get; } = (name != null) ? "111" : value;
+
+			private string? WebValue2;
+		}
+
+		public record FieldBeforeProperty(int ID, string Text)
+		{
+			public int Field;
+
+			public int Property { get; set; }
+		}
+
+		public record FieldsAndPropertiesInterleaved(int ID)
+		{
+			public int First;
+
+			public int Middle { get; set; }
+
+			public int Last;
+		}
+
+		public record PrivateFieldAndComputedProperty(int ID)
+		{
+			public int PublicField;
+
+			private int privateField;
+
+			public int Computed => privateField + PublicField;
+
+			public int Auto { get; set; }
+		}
+
+		public record DerivedWithInterleavedMembers(int B) : Base(B.ToString())
+		{
+			public int Field;
+
+			public int Property { get; set; }
+		}
+	}
+
+#if CS100
+	internal class RecordStructs
+	{
+		public readonly record struct ReadonlyPoint(int X, int Y);
+
+		public record struct Base(string A);
+
+		public record CopyCtor(string A)
+		{
+			protected CopyCtor(CopyCtor _)
+			{
+			}
+		}
+
+		[StructLayout(LayoutKind.Sequential, Size = 1)]
+		public record struct Empty;
+
+		public record struct Fields
+		{
+			public int A;
+			public double B;
+			public object C;
+			public dynamic D;
+			public string S;
+		}
+
+		public record struct Interface(int B) : IRecord;
+
+		public interface IRecord
+		{
+		}
+
+		public record struct Pair<A, B>
+		{
+			public A First { get; init; }
+			public B Second { get; init; }
+		}
+
+		public record struct PairWithPrimaryCtor<A, B>(A First, B Second);
+
+		public readonly record struct BoundsInfo(int Profile, Bounds Bounds);
+
+		public readonly record struct Bounds(ulong Small, ulong Large);
+
+		public record struct PrimaryCtor(int A, string B);
+
+		public record struct MultipleCtorsNoPrimaryCtor
+		{
+			public Guid Id { get; }
+
+			public MultipleCtorsNoPrimaryCtor()
+			{
+				Id = Guid.NewGuid();
+			}
+
+			public MultipleCtorsNoPrimaryCtor(Guid id)
+			{
+				Id = id;
+			}
+		}
+
+		public record struct MultipleCtorsChainedNoPrimaryCtor
+		{
+			public int A { get; init; }
+			public string B { get; init; }
+
+			public double C { get; init; }
+
+			public MultipleCtorsChainedNoPrimaryCtor(double c)
+			{
+				A = 0;
+				B = null;
+				C = c;
+			}
+
+			public MultipleCtorsChainedNoPrimaryCtor(int a)
+				: this(3.14)
+			{
+				A = a;
+			}
+
+			public MultipleCtorsChainedNoPrimaryCtor(string b)
+				: this(4.13)
+			{
+				B = b;
+			}
+		}
+
+		public record struct PrimaryCtorWithAttribute([RecordTest("param")][property: RecordTest("property")][field: RecordTest("field")] int a);
+		public record struct PrimaryCtorWithField(int A, string B)
+		{
+			public double C = 1.0;
+			public string D = A + B;
+		}
+		public record struct PrimaryCtorWithInParameter(in int A, in string B);
+		public record struct PrimaryCtorWithProperty(int A, string B)
+		{
+			public double C { get; init; } = 1.0;
+			public string D { get; } = A + B;
+		}
+
+		public record struct Properties
+		{
+			public int A { get; set; }
+			public int B { get; }
+			public int C => 43;
+			public object O { get; set; }
+			public string S { get; set; }
+			public dynamic D { get; set; }
+
+			public Properties()
+			{
+				A = 41;
+				B = 42;
+				O = null;
+				S = "Hello";
+				D = null;
+			}
+		}
+
+		public record struct PropertiesWithInitializers()
+		{
+			public int A { get; set; } = 41;
+			public int B { get; } = 42;
+			public int C => 43;
+			public object O { get; set; } = null;
+			public string S { get; set; } = "Hello";
+			public dynamic D { get; set; } = null;
+		}
+
+		[AttributeUsage(AttributeTargets.All)]
+		public class RecordTestAttribute : Attribute
+		{
+			public RecordTestAttribute(string name)
+			{
+			}
+		}
+
+		public class WithExpressionTests
+		{
+			public Fields Test(Fields input)
+			{
+				return input with {
+					A = 42,
+					B = 3.141,
+					C = input
+				};
+			}
+			public Fields Test2(Fields input)
+			{
+				return input with {
+					A = 42,
+					B = 3.141,
+					C = input with {
+						A = 43
+					}
+				};
+			}
+		}
+#if CS110
+		public record struct WithRequiredMembers
+		{
+			public int A { get; set; }
+			public required double B { get; set; }
+			public object C;
+			public required dynamic D;
+		}
+#endif
+		public record struct RecordWithMultipleCtors
+		{
+			public int A { get; set; }
+
+			public RecordWithMultipleCtors()
+			{
+				A = 42;
+			}
+
+			public RecordWithMultipleCtors(int A)
+			{
+				this.A = A;
+			}
+
+			public RecordWithMultipleCtors(string A)
+			{
+				this.A = int.Parse(A);
+			}
+		}
+
+		public record struct RecordCtorChain(int A, string B)
+		{
+#if EXPECTED_OUTPUT
+			public double C = 0.0;
+#else
+			public double C;
+#endif
+			public RecordCtorChain(int A)
+				: this(A, "default")
+			{
+				C = 3.14;
+			}
+			public RecordCtorChain(string B)
+				: this(42, B)
+			{
+				C = 1.41;
+			}
+		}
+
+		private static BoundsInfo GetInfo()
+		{
+			return new BoundsInfo(1, new Bounds(2uL, 3uL));
+		}
+
+		public static void NestedDeconstruction()
+		{
+			var (value, (value2, value3)) = GetInfo();
+			Console.WriteLine(value);
+			Console.WriteLine(value2);
+			Console.WriteLine(value3);
+		}
+	}
+
+	internal class RecordsWithCustomSynthesizedMembers
+	{
+		public record WithCustomToString(int A)
+		{
+			public sealed override string ToString()
+			{
+				return "custom";
+			}
+		}
+
+		public record WithCustomPrintMembers(int A)
+		{
+			protected virtual bool PrintMembers(StringBuilder builder)
+			{
+				builder.Append("X");
+				return true;
+			}
+		}
+	}
+#endif
+}

ICSharpCode.Decompiler/CSharp/CallBuilder.cs

@@ -26,6 +26,7 @@ using System.Text;
 
 using ICSharpCode.Decompiler.CSharp.Resolver;
 using ICSharpCode.Decompiler.CSharp.Syntax;
+using ICSharpCode.Decompiler.CSharp.Transforms;
 using ICSharpCode.Decompiler.IL;
 using ICSharpCode.Decompiler.IL.Transforms;
 using ICSharpCode.Decompiler.Semantics;
@@ -594,7 +595,8 @@ namespace ICSharpCode.Decompiler.CSharp
 			if (settings.LiftNullables && method.Name == "GetValueOrDefault"
 				&& method.DeclaringType.IsKnownType(KnownTypeCode.NullableOfT)
 				&& method.DeclaringType.TypeArguments[0].IsKnownType(KnownTypeCode.Boolean)
-				&& argumentList.Length == 0)
+				&& argumentList.Length == 0
+				&& !IntroduceQueryExpressions.IsNullConditional(target))
 			{
 				argumentList.CheckNoNamedOrOptionalArguments();
 				return new BinaryOperatorExpression(
@@ -1318,8 +1320,8 @@ namespace ICSharpCode.Decompiler.CSharp
 				return false;
 
 			var firstArgument = argumentList.Arguments[0];
-			bool canWriteTypeArguments = !settings.AnonymousTypes || !method.TypeArguments.Any(a => a.ContainsAnonymousType());
-			bool writeTypeArguments = (transform & ReferenceTransformation.RequireTypeArguments) != 0 && canWriteTypeArguments;
+			bool writeTypeArguments = (transform & ReferenceTransformation.RequireTypeArguments) != 0
+				&& (!settings.AnonymousTypes || !method.TypeArguments.Any(a => a.ContainsAnonymousType()));
 			IType[] typeArguments = writeTypeArguments ? method.TypeArguments.ToArray() : Empty<IType>.Array;
 
 			var directionExpression = firstArgument.Expression as DirectionExpression;
@@ -1342,20 +1344,10 @@ namespace ICSharpCode.Decompiler.CSharp
 			string[]? remainingNames = argumentNames?.Take(actualArgumentCount).Skip(1).ToArray();
 			if (remainingNames != null && remainingNames.All(name => name == null))
 				remainingNames = null;
-			var remainingArguments = argumentList.GetArgumentResolveResults(skipCount: 1).ToArray();
-			if (!resolver.CanTransformToExtensionMethodCall(method, typeArguments, target, remainingArguments, remainingNames))
+			if (!resolver.CanTransformToExtensionMethodCall(method, typeArguments, target,
+				argumentList.GetArgumentResolveResults(skipCount: 1).ToArray(), remainingNames))
 			{
-				// 'a?.M()' has no static call form to fall back to. Spelled-out type arguments rule out
-				// extension methods of a different arity, which NullPropagationTransform relies on.
-				if (writeTypeArguments || !canWriteTypeArguments || method.TypeArguments.Count == 0
-					|| !IsNullConditional(firstArgument.Expression))
-				{
-					return false;
-				}
-				writeTypeArguments = true;
-				typeArguments = method.TypeArguments.ToArray();
-				if (!resolver.CanTransformToExtensionMethodCall(method, typeArguments, target, remainingArguments, remainingNames))
-					return false;
+				return false;
 			}
 
 			Expression targetExpression;

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -1825,6 +1825,22 @@ namespace ICSharpCode.Decompiler.CSharp
 			}
 		}
 
+		IType PreferNativeIntegerType(IType type)
+		{
+			if (settings.NativeIntegers)
+			{
+				if (type.IsKnownType(KnownTypeCode.IntPtr))
+				{
+					return SpecialType.NInt;
+				}
+				else if (type.IsKnownType(KnownTypeCode.UIntPtr))
+				{
+					return SpecialType.NUInt;
+				}
+			}
+			return type;
+		}
+
 		/// <summary>
 		/// Gets a type used for performing arithmetic with the stack type and sign.
 		/// 
@@ -3525,16 +3541,9 @@ namespace ICSharpCode.Decompiler.CSharp
 		{
 			IType targetType = inst.Type;
 			var arg = Translate(inst.Argument, typeHint: targetType);
-			if (settings.NativeIntegers && !arg.Type.Equals(targetType))
+			if (!arg.Type.Equals(targetType))
 			{
-				if (targetType.IsKnownType(KnownTypeCode.IntPtr))
-				{
-					targetType = SpecialType.NInt;
-				}
-				else if (targetType.IsKnownType(KnownTypeCode.UIntPtr))
-				{
-					targetType = SpecialType.NUInt;
-				}
+				targetType = PreferNativeIntegerType(targetType);
 			}
 			arg = arg.ConvertTo(targetType, this);
 			var obj = compilation.FindType(KnownTypeCode.Object);
@@ -3784,7 +3793,7 @@ namespace ICSharpCode.Decompiler.CSharp
 						{
 							var property = (IProperty)lastElement.Member;
 							Debug.Assert(property.Parameters.Count == indices);
-							Debug.Assert(property.Setter != null, $"Indexer property {property} has no setter");
+							DecompilerAssert.That(property.Setter != null, $"Indexer property {property} has no setter");
 							elementsStack.Peek().Add(
 								new CallBuilder(this, typeSystem, settings)
 									.BuildDictionaryInitializerExpression(lastElement.OpCode, property.Setter, initObjRR, GetIndices(lastElement.Indices, indexVariables).ToList(), info.Values!.Single())
@@ -4051,13 +4060,22 @@ namespace ICSharpCode.Decompiler.CSharp
 
 		TranslatedExpression TranslateWithInitializer(Block block)
 		{
-			var stloc = block.Instructions.FirstOrDefault() as StLoc;
-			var final = block.FinalInstruction as LdLoc;
-			if (stloc == null || final == null || stloc.Variable != final.Variable || stloc.Variable.Kind != VariableKind.InitializerTarget)
+			if (block.Instructions.FirstOrDefault() is not StLoc stloc
+				|| block.FinalInstruction is not LdLoc final
+				|| stloc.Variable != final.Variable || stloc.Variable.Kind != VariableKind.InitializerTarget)
+			{
 				throw new ArgumentException("given Block is invalid!");
+			}
+			ILInstruction oldValue = stloc.Value;
+			if (stloc.Variable.Type.IsReferenceType == true)
+			{
+				// reference types must involve a <Clone>$() call
+				Debug.Assert(TransformCollectionAndObjectInitializers.IsRecordCloneMethodCall((CallInstruction)stloc.Value));
+				oldValue = ((CallInstruction)stloc.Value).Arguments.Single();
+			}
 
 			WithInitializerExpression withInitializerExpression = new WithInitializerExpression();
-			withInitializerExpression.Expression = Translate(stloc.Value, stloc.Variable.Type);
+			withInitializerExpression.Expression = Translate(oldValue, stloc.Variable.Type);
 			withInitializerExpression.Initializer = BuildArrayInitializerExpression(block, new InitializedObjectResolveResult(stloc.Variable.Type));
 
 			return withInitializerExpression.WithILInstruction(block)
@@ -4241,7 +4259,7 @@ namespace ICSharpCode.Decompiler.CSharp
 						}
 						else
 						{
-							targetType = inst.InferType(compilation);
+							targetType = PreferNativeIntegerType(inst.InferType(compilation));
 						}
 					}
 				}
@@ -4539,7 +4557,12 @@ namespace ICSharpCode.Decompiler.CSharp
 				}
 			}
 
-			var value = Translate(inst.Value, typeHint: expectedType);
+			var operand = inst.Value;
+			if (operand is LdObjIfRef ldObjIfRef)
+			{
+				operand = ldObjIfRef.Target;
+			}
+			var value = Translate(operand, typeHint: expectedType);
 			if (value.Expression is DirectionExpression)
 			{
 				// we can deference the managed reference by stripping away the 'ref'

ICSharpCode.Decompiler/CSharp/Transforms/IntroduceQueryExpressions.cs

@@ -0,0 +1,457 @@
+// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+#nullable enable
+
+using System;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using System.Linq;
+
+using ICSharpCode.Decompiler.CSharp.Syntax;
+using ICSharpCode.Decompiler.IL;
+using ICSharpCode.Decompiler.Semantics;
+
+namespace ICSharpCode.Decompiler.CSharp.Transforms
+{
+	/// <summary>
+	/// Decompiles query expressions.
+	/// Based on C# 4.0 spec, §7.16.2 Query expression translation
+	/// </summary>
+	public class IntroduceQueryExpressions : IAstTransform
+	{
+		[AllowNull]
+		TransformContext context;
+
+		public void Run(AstNode rootNode, TransformContext context)
+		{
+			if (!context.Settings.QueryExpressions)
+				return;
+			this.context = context;
+			DecompileQueries(rootNode);
+			// After all queries were decompiled, detect degenerate queries (queries not property terminated with 'select' or 'group')
+			// and fix them, either by adding a degenerate select, or by combining them with another query.
+			foreach (QueryExpression query in rootNode.Descendants.OfType<QueryExpression>())
+			{
+				QueryFromClause fromClause = (QueryFromClause)query.Clauses.First();
+				if (IsDegenerateQuery(query))
+				{
+					// introduce select for degenerate query
+					context.Step("Add degenerate query select clause", query);
+					query.Clauses.Add(new QuerySelectClause { Expression = new IdentifierExpression(fromClause.Identifier).CopyAnnotationsFrom(fromClause) });
+				}
+				// See if the data source of this query is a degenerate query,
+				// and combine the queries if possible.
+				QueryExpression? innerQuery = fromClause.Expression as QueryExpression;
+				while (innerQuery != null && IsDegenerateQuery(innerQuery))
+				{
+					QueryFromClause innerFromClause = (QueryFromClause)innerQuery.Clauses.First();
+					ILVariable? innerVariable = innerFromClause.Annotation<ILVariableResolveResult>()?.Variable;
+					ILVariable? rangeVariable = fromClause.Annotation<ILVariableResolveResult>()?.Variable;
+					context.Step("Combine nested query clauses", fromClause);
+					// Replace the fromClause with all clauses from the inner query
+					fromClause.Remove();
+					QueryClause? insertionPos = null;
+					foreach (var clause in innerQuery.Clauses)
+					{
+						CombineRangeVariables(clause, innerVariable, rangeVariable);
+						query.Clauses.InsertAfter(insertionPos, insertionPos = clause.Detach());
+					}
+					context.EndStep(innerFromClause);
+					fromClause = innerFromClause;
+					innerQuery = fromClause.Expression as QueryExpression;
+				}
+			}
+		}
+
+		private void CombineRangeVariables(QueryClause clause, ILVariable? oldVariable, ILVariable? newVariable)
+		{
+			if (oldVariable == null || newVariable == null)
+				return;
+			foreach (var identifier in clause.DescendantNodes().OfType<Identifier>())
+			{
+				var parent = identifier.Parent;
+				if (parent == null)
+					continue;
+				var variable = parent.Annotation<ILVariableResolveResult>()?.Variable;
+				if (variable == oldVariable)
+				{
+					context.Step("Combine query range variables", identifier);
+					parent.RemoveAnnotations<ILVariableResolveResult>();
+					parent.AddAnnotation(new ILVariableResolveResult(newVariable));
+					var newIdentifier = Identifier.Create(newVariable.Name!);
+					identifier.ReplaceWith(newIdentifier);
+					context.EndStep(newIdentifier);
+				}
+			}
+		}
+
+		bool IsDegenerateQuery(QueryExpression? query)
+		{
+			if (query == null)
+				return false;
+			var lastClause = query.Clauses.LastOrDefault();
+			return !(lastClause is QuerySelectClause || lastClause is QueryGroupClause);
+		}
+
+		void DecompileQueries(AstNode node)
+		{
+			Expression? query = DecompileQuery(node as InvocationExpression);
+			if (query != null)
+			{
+				if (node.Parent is ExpressionStatement && CanUseDiscardAssignment())
+					query = new AssignmentExpression(new IdentifierExpression("_"), query);
+				node.ReplaceWith(query);
+				context.EndStep(query);
+			}
+
+			AstNode? next;
+			for (AstNode? child = (query ?? node).FirstChild; child != null; child = next)
+			{
+				// store reference to next child before transformation
+				next = child.NextSibling;
+				DecompileQueries(child);
+			}
+		}
+
+		bool CanUseDiscardAssignment()
+		{
+			// TODO : check whether there exists a variable named '_' in scope.
+			return context.Settings.Discards;
+		}
+
+		QueryExpression? DecompileQuery(InvocationExpression? invocation)
+		{
+			if (invocation == null)
+				return null;
+			MemberReferenceExpression? mre = invocation.Target as MemberReferenceExpression;
+			if (mre == null || IsNullConditional(mre.Target))
+				return null;
+			if (mre.TypeArguments.Count > 0)
+				return null;
+			switch (mre.MemberName)
+			{
+				case "Select":
+				{
+					if (invocation.Arguments.Count != 1)
+						return null;
+					if (!IsComplexQuery(mre))
+						return null;
+					Expression expr = invocation.Arguments.Single();
+					if (MatchSimpleLambda(expr, out var parameter, out var body))
+					{
+						context.Step("Build select query", invocation);
+						QueryExpression query = new QueryExpression();
+						query.Clauses.Add(MakeFromClause(parameter, mre.Target.Detach()));
+						query.Clauses.Add(new QuerySelectClause { Expression = WrapExpressionInParenthesesIfNecessary(body.Detach(), parameter.Name!) }.CopyAnnotationsFrom(expr));
+						return query;
+					}
+					return null;
+				}
+				case "GroupBy":
+				{
+					if (invocation.Arguments.Count == 2)
+					{
+						Expression keyLambda = invocation.Arguments.ElementAt(0);
+						Expression projectionLambda = invocation.Arguments.ElementAt(1);
+						if (MatchSimpleLambda(keyLambda, out var parameter1, out var keySelector)
+							&& MatchSimpleLambda(projectionLambda, out var parameter2, out var elementSelector)
+							&& parameter1.Name == parameter2.Name)
+						{
+							context.Step("Build group query", invocation);
+							QueryExpression query = new QueryExpression();
+							query.Clauses.Add(MakeFromClause(parameter1, mre.Target.Detach()));
+							var queryGroupClause = new QueryGroupClause {
+								Projection = elementSelector.Detach(),
+								Key = keySelector.Detach()
+							};
+							// The matched group-by lambdas always carry their ILFunction annotation.
+							queryGroupClause.AddAnnotation(new QueryGroupClauseAnnotation(keyLambda.Annotation<IL.ILFunction>()!, projectionLambda.Annotation<IL.ILFunction>()!));
+							query.Clauses.Add(queryGroupClause);
+							return query;
+						}
+					}
+					else if (invocation.Arguments.Count == 1)
+					{
+						Expression lambda = invocation.Arguments.Single();
+						if (MatchSimpleLambda(lambda, out var parameter, out var keySelector))
+						{
+							context.Step("Build group query", invocation);
+							QueryExpression query = new QueryExpression();
+							query.Clauses.Add(MakeFromClause(parameter, mre.Target.Detach()));
+							query.Clauses.Add(new QueryGroupClause { Projection = new IdentifierExpression(parameter.Name!).CopyAnnotationsFrom(parameter), Key = keySelector.Detach() });
+							return query;
+						}
+					}
+					return null;
+				}
+				case "SelectMany":
+				{
+					if (invocation.Arguments.Count != 2)
+						return null;
+					var fromExpressionLambda = invocation.Arguments.ElementAt(0);
+					if (!MatchSimpleLambda(fromExpressionLambda, out var parameter, out var collectionSelector))
+						return null;
+					if (IsNullConditional(collectionSelector))
+						return null;
+					LambdaExpression? lambda = invocation.Arguments.ElementAt(1) as LambdaExpression;
+					if (lambda != null && lambda.Parameters.Count == 2 && lambda.Body is Expression)
+					{
+						ParameterDeclaration p1 = lambda.Parameters.ElementAt(0);
+						ParameterDeclaration p2 = lambda.Parameters.ElementAt(1);
+						if (p1.Name == parameter.Name)
+						{
+							context.Step("Build select-many query", invocation);
+							QueryExpression query = new QueryExpression();
+							query.Clauses.Add(MakeFromClause(p1, mre.Target.Detach()));
+							query.Clauses.Add(MakeFromClause(p2, collectionSelector.Detach()).CopyAnnotationsFrom(fromExpressionLambda));
+							query.Clauses.Add(new QuerySelectClause { Expression = WrapExpressionInParenthesesIfNecessary(((Expression)lambda.Body).Detach(), parameter.Name!) });
+							return query;
+						}
+					}
+					return null;
+				}
+				case "Where":
+				{
+					if (invocation.Arguments.Count != 1)
+						return null;
+					if (!IsComplexQuery(mre))
+						return null;
+					Expression expr = invocation.Arguments.Single();
+					if (MatchSimpleLambda(expr, out var parameter, out var body))
+					{
+						context.Step("Build where query", invocation);
+						QueryExpression query = new QueryExpression();
+						query.Clauses.Add(MakeFromClause(parameter, mre.Target.Detach()));
+						query.Clauses.Add(new QueryWhereClause { Condition = body.Detach() }.CopyAnnotationsFrom(expr));
+						return query;
+					}
+					return null;
+				}
+				case "OrderBy":
+				case "OrderByDescending":
+				case "ThenBy":
+				case "ThenByDescending":
+				{
+					if (invocation.Arguments.Count != 1)
+						return null;
+					if (!IsComplexQuery(mre))
+						return null;
+					var lambda = invocation.Arguments.Single();
+					if (MatchSimpleLambda(lambda, out var parameter, out var orderExpression))
+					{
+						if (ValidateThenByChain(invocation, parameter.Name!))
+						{
+							context.Step("Build order query", invocation);
+							QueryOrderClause orderClause = new QueryOrderClause();
+							while (mre.MemberName == "ThenBy" || mre.MemberName == "ThenByDescending")
+							{
+								// insert new ordering at beginning
+								orderClause.Orderings.InsertAfter(
+									null, new QueryOrdering {
+										Expression = orderExpression.Detach(),
+										Direction = (mre.MemberName == "ThenBy" ? QueryOrderingDirection.None : QueryOrderingDirection.Descending)
+									}.CopyAnnotationsFrom(lambda));
+
+								InvocationExpression tmp = (InvocationExpression)mre.Target;
+								mre = (MemberReferenceExpression)tmp.Target;
+								lambda = tmp.Arguments.Single();
+								// ValidateThenByChain already confirmed every clause in the chain is a simple
+								// lambda, so this match always succeeds.
+								bool matched = MatchSimpleLambda(lambda, out parameter, out orderExpression);
+								Debug.Assert(matched);
+								Debug.Assert(orderExpression != null);
+							}
+							// The chain was validated and every iteration re-matched a simple lambda,
+							// so the final range-variable parameter is set.
+							Debug.Assert(parameter != null);
+							// insert new ordering at beginning
+							orderClause.Orderings.InsertAfter(
+								null, new QueryOrdering {
+									Expression = orderExpression.Detach(),
+									Direction = (mre.MemberName == "OrderBy" ? QueryOrderingDirection.None : QueryOrderingDirection.Descending)
+								}.CopyAnnotationsFrom(lambda));
+
+							QueryExpression query = new QueryExpression();
+							query.Clauses.Add(MakeFromClause(parameter, mre.Target.Detach()));
+							query.Clauses.Add(orderClause);
+							return query;
+						}
+					}
+					return null;
+				}
+				case "Join":
+				case "GroupJoin":
+				{
+					if (invocation.Arguments.Count != 4)
+						return null;
+					Expression source1 = mre.Target;
+					Expression source2 = invocation.Arguments.ElementAt(0);
+					if (IsNullConditional(source2))
+						return null;
+					Expression outerLambda = invocation.Arguments.ElementAt(1);
+					if (!MatchSimpleLambda(outerLambda, out var element1, out var key1))
+						return null;
+					Expression innerLambda = invocation.Arguments.ElementAt(2);
+					if (!MatchSimpleLambda(innerLambda, out var element2, out var key2))
+						return null;
+					LambdaExpression? lambda = invocation.Arguments.ElementAt(3) as LambdaExpression;
+					if (lambda != null && lambda.Parameters.Count == 2 && lambda.Body is Expression)
+					{
+						ParameterDeclaration p1 = lambda.Parameters.ElementAt(0);
+						ParameterDeclaration p2 = lambda.Parameters.ElementAt(1);
+						if (ValidateParameter(p1) && ValidateParameter(p2)
+							&& p1.Name == element1.Name && (p2.Name == element2.Name || mre.MemberName == "GroupJoin"))
+						{
+							context.Step(mre.MemberName == "GroupJoin" ? "Build group join query" : "Build join query", invocation);
+							QueryExpression query = new QueryExpression();
+							query.Clauses.Add(MakeFromClause(element1, source1.Detach()));
+							QueryJoinClause joinClause = new QueryJoinClause();
+							joinClause.JoinIdentifier = element2.Name!;    // join elementName2
+							joinClause.JoinIdentifierToken.CopyAnnotationsFrom(element2);
+							joinClause.InExpression = source2.Detach();  // in source2
+							joinClause.OnExpression = key1.Detach();     // on key1
+							joinClause.EqualsExpression = key2.Detach(); // equals key2
+							if (mre.MemberName == "GroupJoin")
+							{
+								joinClause.IntoIdentifier = p2.Name; // into p2.Name
+								joinClause.IntoIdentifierToken!.CopyAnnotationsFrom(p2);
+							}
+							// The matched join key-selector lambdas always carry their ILFunction annotation.
+							joinClause.AddAnnotation(new QueryJoinClauseAnnotation(outerLambda.Annotation<IL.ILFunction>()!, innerLambda.Annotation<IL.ILFunction>()!));
+							query.Clauses.Add(joinClause);
+							query.Clauses.Add(new QuerySelectClause { Expression = ((Expression)lambda.Body).Detach() }.CopyAnnotationsFrom(lambda));
+							return query;
+						}
+					}
+					return null;
+				}
+				default:
+					return null;
+			}
+		}
+
+		static bool IsComplexQuery(MemberReferenceExpression mre)
+		{
+			return (mre.Target is InvocationExpression && mre.Parent is InvocationExpression) || mre.Parent?.Parent is QueryClause;
+		}
+
+		QueryFromClause MakeFromClause(ParameterDeclaration parameter, Expression body)
+		{
+			QueryFromClause fromClause = new QueryFromClause {
+				Identifier = parameter.Name!,
+				Expression = body
+			};
+			fromClause.CopyAnnotationsFrom(parameter);
+			return fromClause;
+		}
+
+		class ApplyAnnotationVisitor : DepthFirstAstVisitor<AstNode>
+		{
+			private LetIdentifierAnnotation annotation;
+			private string identifier;
+
+			public ApplyAnnotationVisitor(LetIdentifierAnnotation annotation, string identifier)
+			{
+				this.annotation = annotation;
+				this.identifier = identifier;
+			}
+
+			public override AstNode VisitIdentifier(Identifier identifier)
+			{
+				if (identifier.Name == this.identifier)
+					identifier.AddAnnotation(annotation);
+				return identifier;
+			}
+		}
+
+		internal static bool IsNullConditional(Expression target) => target switch {
+			UnaryOperatorExpression { Operator: UnaryOperatorType.NullConditional } => true,
+			MemberReferenceExpression member => IsNullConditional(member.Target),
+			InvocationExpression invocation => IsNullConditional(invocation.Target),
+			IndexerExpression { Target: { } indexerTarget } => IsNullConditional(indexerTarget),
+			_ => false
+		};
+
+		/// <summary>
+		/// This fixes #437: Decompilation of query expression loses material parentheses
+		/// We wrap the expression in parentheses if:
+		/// - the Select-call is explicit (see caller(s))
+		/// - the expression is a plain identifier matching the parameter name
+		/// </summary>
+		Expression WrapExpressionInParenthesesIfNecessary(Expression expression, string parameterName)
+		{
+			if (expression is IdentifierExpression ident && parameterName.Equals(ident.Identifier, StringComparison.Ordinal))
+				return new ParenthesizedExpression(expression);
+			return expression;
+		}
+
+		/// <summary>
+		/// Ensure that all ThenBy's are correct, and that the list of ThenBy's is terminated by an 'OrderBy' invocation.
+		/// </summary>
+		bool ValidateThenByChain(InvocationExpression? invocation, string expectedParameterName)
+		{
+			if (invocation == null || invocation.Arguments.Count != 1)
+				return false;
+			if (!(invocation.Target is MemberReferenceExpression mre))
+				return false;
+			if (!MatchSimpleLambda(invocation.Arguments.Single(), out var parameter, out _))
+				return false;
+			if (parameter.Name != expectedParameterName)
+				return false;
+			if (mre.TypeArguments.Count > 0)
+				return false;
+
+			if (mre.MemberName == "OrderBy" || mre.MemberName == "OrderByDescending")
+				return !IsNullConditional(mre.Target);
+			else if (mre.MemberName == "ThenBy" || mre.MemberName == "ThenByDescending")
+				return ValidateThenByChain(mre.Target as InvocationExpression, expectedParameterName);
+			else
+				return false;
+		}
+
+		/// <summary>Matches simple lambdas of the form "a => b"</summary>
+		bool MatchSimpleLambda(Expression expr, [NotNullWhen(true)] out ParameterDeclaration? parameter, [NotNullWhen(true)] out Expression? body)
+		{
+			if (expr is LambdaExpression lambda && lambda.Parameters.Count == 1 && lambda.Body is Expression)
+			{
+				if (lambda.GetResolveResult() is DecompiledLambdaResolveResult { AttemptedConversionWithTypeMismatch: true })
+				{
+					parameter = null;
+					body = null;
+					return false;
+				}
+				ParameterDeclaration p = lambda.Parameters.Single();
+				if (ValidateParameter(p))
+				{
+					parameter = p;
+					body = (Expression)lambda.Body;
+					return true;
+				}
+			}
+			parameter = null;
+			body = null;
+			return false;
+		}
+
+		private static bool ValidateParameter(ParameterDeclaration p)
+		{
+			return p.ParameterModifier == Decompiler.TypeSystem.ReferenceKind.None && p.Attributes.Count == 0;
+		}
+	}
+}

ICSharpCode.Decompiler/IL/Transforms/ILInlining.cs

@@ -668,12 +668,17 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				case OpCode.SwitchInstruction:
 					return true;
 				case OpCode.LdLoc:
-					if (v.StateMachineField == null && ((LdLoc)inlinedExpression).Variable.StateMachineField != null)
+					var copiedVariable = ((LdLoc)inlinedExpression).Variable;
+					if (v.StateMachineField == null && copiedVariable.StateMachineField != null)
 					{
 						// Roslyn likes to put the result of fetching a state machine field into a temporary variable,
 						// so inline more aggressively in such cases.
 						return true;
 					}
+					if (IsHoistedCompilerTemporary(v) && IsHoistedCompilerTemporary(copiedVariable))
+					{
+						return true;
+					}
 					break;
 			}
 			if (inlinedExpression.ResultType == StackType.Ref)
@@ -773,6 +778,13 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			}
 		}
 
+		static bool IsHoistedCompilerTemporary(ILVariable v)
+		{
+			string name = v.StateMachineField?.Name;
+			return name != null
+				&& (name.StartsWith("<>7__wrap", StringComparison.Ordinal) || name.StartsWith("<>s__", StringComparison.Ordinal));
+		}
+
 		/// <summary>
 		/// Gets whether 'expressionBeingMoved' can be inlined into 'expr'.
 		/// </summary>
@@ -942,10 +954,6 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				for (int i = 0; i < childIndex; ++i)
 				{
 					ILInstruction predecessor = inst.Parent.Children[i];
-					// The variable of a named argument only exists within its block,
-					// so only the stored value can interfere with the moved expression.
-					if (predecessor is StLoc { Variable.Kind: VariableKind.NamedArgument } namedArgument)
-						predecessor = namedArgument.Value;
 					if (!IsSafeForInlineOver(predecessor, expressionBeingMoved))
 						return false;
 				}

README.md

@@ -0,0 +1,12 @@
+# Contributions to icsharpcode/ILSpy
+
+.NET Decompiler with support for PDB generation, ReadyToRun, Metadata (&more) - cross-platform!
+
+This repository holds only my commits to the upstream project, with their original author, date and diff.
+Each of my commits is preceded by a snapshot of the upstream files it touched, so every diff shows exactly what I changed.
+
+## Merged pull requests
+
+- [Fix #4137: Keep nint in conditionals with mixed native int branches](https://github.com/icsharpcode/ILSpy/pull/4232) (2026-10-11)
+- [Remove the delegate cache left by a discarded method-group conversion](https://github.com/icsharpcode/ILSpy/pull/4133) (2026-09-19)
+- [Recognize a VB exception filter's type test](https://github.com/icsharpcode/ILSpy/pull/4134) (2026-09-15)