From e6bc300e1eeb3378a7c71411a202623d385f3877 Mon Sep 17 00:00:00 2001
From: Daniel Grunwald <daniel@danielgrunwald.de>
Date: Fri, 5 Oct 2012 02:23:55 +0200
Subject: [PATCH] Don't show "expression is never of the provided type" warning
 if the type could not be resolved.

---
 .../ExpressionIsNeverOfProvidedTypeIssue.cs   |  2 ++
 ...pressionIsNeverOfProvidedTypeIssueTests.cs | 28 +++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ExpressionIsNeverOfProvidedTypeIssue.cs b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ExpressionIsNeverOfProvidedTypeIssue.cs
index ed10a12d8f..543b2bdb61 100644
--- a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ExpressionIsNeverOfProvidedTypeIssue.cs
+++ b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ExpressionIsNeverOfProvidedTypeIssue.cs
@@ -61,6 +61,8 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 				var exprType = ctx.Resolve (isExpression.Expression).Type;
 				var providedType = ctx.ResolveType (isExpression.Type);
 
+				if (exprType.Kind == TypeKind.Unknown || providedType.Kind == TypeKind.Unknown)
+					return;
 				if (IsValidReferenceOrBoxingConversion(exprType, providedType))
 					return;
 				
diff --git a/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ExpressionIsNeverOfProvidedTypeIssueTests.cs b/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ExpressionIsNeverOfProvidedTypeIssueTests.cs
index e3c006fe2f..1270a20c3f 100644
--- a/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ExpressionIsNeverOfProvidedTypeIssueTests.cs
+++ b/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ExpressionIsNeverOfProvidedTypeIssueTests.cs
@@ -270,6 +270,34 @@ sealed class TestClass
 	{
 		if (x is string[]) ;
 	}
+}";
+			Test<ExpressionIsNeverOfProvidedTypeIssue> (input, 0);
+		}
+		
+		[Test]
+		public void UnknownExpression()
+		{
+			var input = @"
+sealed class TestClass
+{
+	void TestMethod ()
+	{
+		if (unknown is string) ;
+	}
+}";
+			Test<ExpressionIsNeverOfProvidedTypeIssue> (input, 0);
+		}
+		
+		[Test]
+		public void UnknownType()
+		{
+			var input = @"
+sealed class TestClass
+{
+	void TestMethod (int x)
+	{
+		if (x is unknown) ;
+	}
 }";
 			Test<ExpressionIsNeverOfProvidedTypeIssue> (input, 0);
 		}