ParameterCanBeDemotedIssue: Remove 'ConstructHasLocalIndependentTyping'

This fixes false positives when the parameter is used within lambdas passed to generic methods (e.g. LINQ).

ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ParameterCanBeDemotedIssue/TypeCriteriaCollector.cs

@@ -185,30 +185,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 
 		void CheckForCriterion(Expression expression, IVariable variable)
 		{
-			if (ConstructHasLocalIndependentTyping(expression)) {
-				AddCriterion(variable, new IsTypeCriterion(context.GetExpectedType(expression)));
-			}
-		}
-
-		bool ConstructHasLocalIndependentTyping(AstNode astNode)
-		{
-			// TODO: Implement this thing correctly
-			var parent = astNode.Parent;
-			while (!(parent is InvocationExpression || parent is ObjectCreateExpression || parent is Statement))
-				parent = parent.Parent;
-			if (parent is InvocationExpression || parent is ObjectCreateExpression) {
-				var resolveResult = context.Resolve(parent) as InvocationResolveResult;
-				if (resolveResult == null)
-					return true;
-				var specializedMember = resolveResult.Member as SpecializedMethod;
-				return specializedMember == null || specializedMember.TypeParameters.Count == 0;
-			}
-			var initializer = parent as VariableDeclarationStatement;
-			if (initializer != null) {
-				return initializer.Type.GetText() != "var";
-			}
-
-			return true;
+			AddCriterion(variable, new IsTypeCriterion(context.GetExpectedType(expression)));
 		}
 
 		class ConjunctionCriteria : ITypeCriterion

ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ParameterCanBeDemotedIssue/ParameterCanBeDemotedTests.cs

@@ -423,22 +423,7 @@ class Test
 }";
 			TestRefactoringContext context;
 			var issues = GetIssues(new ParameterCanBeDemotedIssue(), input, out context);
-			Assert.AreEqual(1, issues.Count);
-			var issue = issues [0];
-			Assert.AreEqual(1, issue.Actions.Count);
-			
-			CheckFix(context, issues [0], baseInput + @"
-class Test
-{
-	void F(IA b)
-	{
-		Generic (b);
-	}
-
-	void Generic<T> (T arg) where T : IA
-	{
-	}
-}");
+			Assert.AreEqual(0, issues.Count);
 		}
 
 		[Test]
@@ -459,23 +444,7 @@ class Test
 }";
 			TestRefactoringContext context;
 			var issues = GetIssues(new ParameterCanBeDemotedIssue(), input, out context);
-			Assert.AreEqual(1, issues.Count);
-			var issue = issues [0];
-			Assert.AreEqual(1, issue.Actions.Count);
-			
-			CheckFix(context, issues [0], baseInput + @"
-class Test
-{
-	void Foo (IA b)
-	{
-		var b2 = b;
-		Foo (b2);
-	}
-
-	void Foo (IA a)
-	{
-	}
-}");
+			Assert.AreEqual(0, issues.Count);
 		}
 
 		[Test]
@@ -936,6 +905,24 @@ class Test : TestBase
 	}
 }", 0);
 		}
+		
+		[Test]
+		public void DoNotDemoteStringComparisonToReferenceComparison_WithinLambda()
+		{
+			Test<ParameterCanBeDemotedIssue>(@"using System; using System.Linq; using System.Collections.Generic;
+class Test
+{
+	IEnumerable<User> users;
+	User GetUser (String id)
+	{
+		return users.Where(u => u.Name == id).SingleOrDefault();
+	}
+}
+class User {
+	public string Name;
+}
+", 0);
+		}
 	}
 }