From 9e168224ddb970cec2faf674a624fb58e4606c28 Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Sun, 1 Oct 2023 17:58:44 +0200
Subject: [PATCH] Fix #3091: extension methods named "Add" were skipping some
 checks in AccessPathElement.IsMethodApplicable.

---
 .../TestCases/Pretty/InitializerTests.cs             | 12 ++++++++++++
 .../TransformCollectionAndObjectInitializers.cs      |  8 ++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/ICSharpCode.Decompiler.Tests/TestCases/Pretty/InitializerTests.cs b/ICSharpCode.Decompiler.Tests/TestCases/Pretty/InitializerTests.cs
index 3844d22cb..9accce88a 100644
--- a/ICSharpCode.Decompiler.Tests/TestCases/Pretty/InitializerTests.cs
+++ b/ICSharpCode.Decompiler.Tests/TestCases/Pretty/InitializerTests.cs
@@ -34,6 +34,10 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty.InitializerTests
 		public static void Add<T>(this IList<KeyValuePair<string, string>> collection, string key, T value, Func<T, string> convert = null)
 		{
 		}
+
+		public static void Add(this TestCases collection, string key)
+		{
+		}
 	}
 
 	public class TestCases
@@ -1104,6 +1108,14 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty.InitializerTests
 			Console.WriteLine(customList);
 		}
 
+		public static TestCases NoCollectionInitializerBecauseOfMissingIEnumerable()
+		{
+			TestCases testCases = new TestCases();
+			testCases.Add("int");
+			testCases.Add("string");
+			return testCases;
+		}
+
 		public static void CollectionInitializerWithParamsMethod()
 		{
 			X(Y(), new CustomList<int> { { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 } });
diff --git a/ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs b/ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs
index 1f8845d93..781a83c01 100644
--- a/ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs
+++ b/ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs
@@ -439,8 +439,12 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			if (!"Add".Equals(method.Name, StringComparison.Ordinal) || arguments.Count == 0)
 				return false;
 			if (method.IsExtensionMethod)
-				return settings?.ExtensionMethodsInCollectionInitializers != false
-					&& CSharp.Transforms.IntroduceExtensionMethods.CanTransformToExtensionMethodCall(method, resolveContext, ignoreTypeArguments: true);
+			{
+				if (settings?.ExtensionMethodsInCollectionInitializers == false)
+					return false;
+				if (!CSharp.Transforms.IntroduceExtensionMethods.CanTransformToExtensionMethodCall(method, resolveContext, ignoreTypeArguments: true))
+					return false;
+			}
 			var targetType = GetReturnTypeFromInstruction(arguments[0]) ?? rootType;
 			if (targetType == null)
 				return false;