From 53d01869c97c8a89589882a8ef8852fe5b9f216a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maximilian=20Schm=C3=B6cker?= <m.schmoecker@brickfire.eu>
Date: Sat, 5 Jul 2025 16:48:58 +0200
Subject: [PATCH 1/2] Fix incorrect method for static methods with instance
 signature

---
 ICSharpCode.Decompiler/TypeSystem/MetadataModule.cs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ICSharpCode.Decompiler/TypeSystem/MetadataModule.cs b/ICSharpCode.Decompiler/TypeSystem/MetadataModule.cs
index bc7ff1bb4..ec0cdca4e 100644
--- a/ICSharpCode.Decompiler/TypeSystem/MetadataModule.cs
+++ b/ICSharpCode.Decompiler/TypeSystem/MetadataModule.cs
@@ -535,6 +535,8 @@ namespace ICSharpCode.Decompiler.TypeSystem
 					{
 						if (m.TypeParameters.Count != signature.GenericParameterCount)
 							continue;
+						if (signature.Header.IsInstance != !m.IsStatic)
+							continue;
 						if (CompareSignatures(m.Parameters, parameterTypes) && CompareTypes(m.ReturnType, signature.ReturnType))
 						{
 							method = m;

From cc4588db4b6674f56364bc54298fdede0a3ed17a Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Sat, 5 Jul 2025 19:06:46 +0200
Subject: [PATCH 2/2] Add a test case

---
 .../ICSharpCode.Decompiler.Tests.csproj       |  2 ++
 .../ILPrettyTestRunner.cs                     |  6 ++++
 .../TestCases/ILPretty/Issue3504.cs           |  9 +++++
 .../TestCases/ILPretty/Issue3504.il           | 36 +++++++++++++++++++
 4 files changed, 53 insertions(+)
 create mode 100644 ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3504.cs
 create mode 100644 ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3504.il

diff --git a/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj b/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj
index d581a3ffd..50bc5be58 100644
--- a/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj
+++ b/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj
@@ -96,6 +96,7 @@
     <None Include="TestCases\ILPretty\Issue2260SwitchString.il" />
     <None Include="TestCases\ILPretty\Issue3442.il" />
     <None Include="TestCases\ILPretty\Issue3466.il" />
+    <None Include="testcases\ilpretty\Issue3504.il" />
     <None Include="TestCases\ILPretty\MonoFixed.il" />
     <None Include="TestCases\Correctness\NonGenericConstrainedCallVirt.il" />
     <None Include="TestCases\ILPretty\UnknownTypes.cs" />
@@ -138,6 +139,7 @@
     <Compile Include="TestCases\ILPretty\Issue3421.cs" />
     <Compile Include="TestCases\ILPretty\Issue3442.cs" />
     <Compile Include="TestCases\ILPretty\Issue3466.cs" />
+    <None Include="TestCases\ILPretty\Issue3504.cs" />
     <Compile Include="TestCases\ILPretty\MonoFixed.cs" />
     <Compile Include="TestCases\Pretty\Comparisons.cs" />
     <Compile Include="TestCases\Pretty\GloballyQualifiedTypeInStringInterpolation.cs" />
diff --git a/ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs b/ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs
index abdc031fa..57fa18c7c 100644
--- a/ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs
+++ b/ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs
@@ -225,6 +225,12 @@ namespace ICSharpCode.Decompiler.Tests
 			await Run();
 		}
 
+		[Test]
+		public async Task Issue3504()
+		{
+			await Run();
+		}
+
 		[Test]
 		public async Task Issue2260SwitchString()
 		{
diff --git a/ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3504.cs b/ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3504.cs
new file mode 100644
index 000000000..c5d8238f0
--- /dev/null
+++ b/ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3504.cs
@@ -0,0 +1,9 @@
+using System;
+
+internal class Issue3504
+{
+	private void Method(Console console)
+	{
+		console.WriteLine("Hello.");
+	}
+}
diff --git a/ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3504.il b/ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3504.il
new file mode 100644
index 000000000..6637e6f9e
--- /dev/null
+++ b/ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3504.il
@@ -0,0 +1,36 @@
+.class private auto ansi beforefieldinit Issue3504
+	extends [System.Runtime]System.Object
+{
+	// Methods
+	.method private hidebysig 
+		instance void Method (class [System.Console]System.Console console) cil managed 
+	{
+		// Method begins at RVA 0x2050
+		// Header size: 1
+		// Code size: 13 (0xd)
+		.maxstack 8
+
+		IL_0000: nop
+		IL_0001: ldarg.1
+        IL_0002: ldstr "Hello."
+		IL_0007: call instance void [System.Console]System.Console::WriteLine(string)
+		IL_000b: nop
+		IL_000c: ret
+	} // end of method Issue3504::Method
+
+	.method public hidebysig specialname rtspecialname 
+		instance void .ctor () cil managed 
+	{
+		// Method begins at RVA 0x205e
+		// Header size: 1
+		// Code size: 8 (0x8)
+		.maxstack 8
+
+		IL_0000: ldarg.0
+		IL_0001: call instance void [System.Runtime]System.Object::.ctor()
+		IL_0006: nop
+		IL_0007: ret
+	} // end of method Issue3504::.ctor
+
+} // end of class Issue3504
+