Remove constructors from CSharpUnresolvedFile - they could be mistaken to load the specified file name.

ICSharpCode.NRefactory.CSharp/Ast/SyntaxTree.cs

@@ -164,24 +164,28 @@ namespace ICSharpCode.NRefactory.CSharp
 		
 		public static SyntaxTree Parse (string program, string fileName = "", CompilerSettings settings = null, CancellationToken cancellationToken = default (CancellationToken))
 		{
+			cancellationToken.ThrowIfCancellationRequested();
 			var parser = new CSharpParser (settings);
 			return parser.Parse (program, fileName);
 		}
 		
 		public static SyntaxTree Parse (TextReader reader, string fileName = "", CompilerSettings settings = null, CancellationToken cancellationToken = default (CancellationToken))
 		{
+			cancellationToken.ThrowIfCancellationRequested();
 			var parser = new CSharpParser (settings);
 			return parser.Parse (reader, fileName);
 		}
 		
 		public static SyntaxTree Parse (Stream stream, string fileName = "", CompilerSettings settings = null, CancellationToken cancellationToken = default (CancellationToken))
 		{
+			cancellationToken.ThrowIfCancellationRequested();
 			var parser = new CSharpParser (settings);
 			return parser.Parse (stream, fileName);
 		}
 		
 		public static SyntaxTree Parse (ITextSource textSource, string fileName = "", CompilerSettings settings = null, CancellationToken cancellationToken = default (CancellationToken))
 		{
+			cancellationToken.ThrowIfCancellationRequested();
 			var parser = new CSharpParser (settings);
 			return parser.Parse (textSource, fileName);
 		}

ICSharpCode.NRefactory.CSharp/Resolver/ResolveVisitor.cs

@@ -589,7 +589,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 					// Last using scope:
 					usingScope = new UsingScope(resolver.CurrentUsingScope.UnresolvedUsingScope, identifiers.Last().Name);
 					usingScope.Region = region;
-					var cv = new TypeSystemConvertVisitor(new CSharpUnresolvedFile(region.FileName ?? string.Empty), usingScope);
+					var cv = new TypeSystemConvertVisitor(new CSharpUnresolvedFile(), usingScope);
 					ApplyVisitorToUsings(cv, namespaceDeclaration.Children);
 					PushUsingScope(usingScope);
 				}

ICSharpCode.NRefactory.CSharp/TypeSystem/CSharpUnresolvedFile.cs

@@ -36,8 +36,8 @@ namespace ICSharpCode.NRefactory.CSharp.TypeSystem
 		// The 'FastSerializerVersion' attribute on CSharpUnresolvedFile must be incremented when fixing 
 		// bugs in the TypeSystemConvertVisitor
 		
-		readonly string fileName;
-		readonly UsingScope rootUsingScope;
+		string fileName = string.Empty;
+		readonly UsingScope rootUsingScope = new UsingScope();
 		IList<IUnresolvedTypeDefinition> topLevelTypeDefinitions = new List<IUnresolvedTypeDefinition>();
 		IList<IUnresolvedAttribute> assemblyAttributes = new List<IUnresolvedAttribute>();
 		IList<IUnresolvedAttribute> moduleAttributes = new List<IUnresolvedAttribute>();
@@ -55,26 +55,12 @@ namespace ICSharpCode.NRefactory.CSharp.TypeSystem
 			usingScopes = FreezableHelper.FreezeListAndElements(usingScopes);
 		}
 		
-		public CSharpUnresolvedFile(string fileName)
-		{
-			if (fileName == null)
-				throw new ArgumentNullException("fileName");
-			this.fileName = fileName;
-			this.rootUsingScope = new UsingScope();
-		}
-		
-		public CSharpUnresolvedFile(string fileName, UsingScope rootUsingScope)
-		{
-			if (fileName == null)
-				throw new ArgumentNullException("fileName");
-			if (rootUsingScope == null)
-				throw new ArgumentNullException("rootUsingScope");
-			this.fileName = fileName;
-			this.rootUsingScope = rootUsingScope;
-		}
-		
 		public string FileName {
 			get { return fileName; }
+			set {
+				FreezableHelper.ThrowIfFrozen(this);
+				fileName = value ?? string.Empty;
+			}
 		}
 		
 		DateTime? lastWriteTime;

ICSharpCode.NRefactory.CSharp/TypeSystem/TypeSystemConvertVisitor.cs

@@ -75,7 +75,8 @@ namespace ICSharpCode.NRefactory.CSharp.TypeSystem
 		{
 			if (fileName == null)
 				throw new ArgumentNullException("fileName");
-			this.unresolvedFile = new CSharpUnresolvedFile(fileName);
+			this.unresolvedFile = new CSharpUnresolvedFile();
+			this.unresolvedFile.FileName = fileName;
 			this.usingScope = unresolvedFile.RootUsingScope;
 		}
 		

ICSharpCode.NRefactory.Tests/CSharp/CodeCompletion/GetCurrentParameterIndexTests.cs

@@ -54,7 +54,7 @@ namespace ICSharpCode.NRefactory.CSharp.CodeCompletion
 			var doc = new ReadOnlyDocument(editorText.ToString ());
 			var pctx = new CSharpProjectContent();
 			var rctx = new CSharpTypeResolveContext(pctx.CreateCompilation().MainAssembly);
-			var ctxProvider = new DefaultCompletionContextProvider(doc, new CSharpUnresolvedFile("a.cs"));
+			var ctxProvider = new DefaultCompletionContextProvider(doc, new CSharpUnresolvedFile());
 			var engine = new CSharpParameterCompletionEngine(doc, ctxProvider, new ParameterCompletionTests.TestFactory(pctx), pctx, rctx);
 
 			return engine.GetCurrentParameterIndex(trigger, end);

ICSharpCode.NRefactory.Tests/CSharp/CodeDomConvertVisitorTests.cs

@@ -39,7 +39,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		public override void SetUp()
 		{
 			base.SetUp();
-			unresolvedFile = new CSharpUnresolvedFile("test.cs");
+			unresolvedFile = new CSharpUnresolvedFile();
 			unresolvedFile.RootUsingScope.Usings.Add(MakeReference("System"));
 			unresolvedFile.RootUsingScope.Usings.Add(MakeReference("System.Collections.Generic"));
 			unresolvedFile.RootUsingScope.Usings.Add(MakeReference("System.Linq"));

ICSharpCode.NRefactory.Tests/CSharp/Parser/Expression/QueryExpressionTests.cs

@@ -302,6 +302,22 @@ select new { c.Name, o.OrderID, o.Total }",
 					}});
 		}
 
+		[Test]
+		public void LocationOfWhere()
+		{
+			var expr = ParseUtilCSharp.ParseExpression<QueryExpression>("from c in customers where c.City == \"London\" select c");
+			var where = expr.Clauses.ElementAt(1);
+			Assert.That(where.StartLocation, Is.EqualTo(new TextLocation(1, 21)));
+		}
+
+		[Test]
+		public void LocationOfOrderBy()
+		{
+			var expr = ParseUtilCSharp.ParseExpression<QueryExpression>("from c in customers orderby c.City select c");
+			var where = expr.Clauses.ElementAt(1);
+			Assert.That(where.StartLocation, Is.EqualTo(new TextLocation(1, 21)));
+		}
+		
 		[Test]
 		public void ExpressionWithOrderByAndLet()
 		{

ICSharpCode.NRefactory.Tests/TypeSystem/TypeSystemHelper.cs

@@ -32,7 +32,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		
 		public static ICompilation CreateCompilation(params IUnresolvedTypeDefinition[] unresolvedTypeDefinitions)
 		{
-			var unresolvedFile = new CSharpUnresolvedFile("dummy.cs");
+			var unresolvedFile = new CSharpUnresolvedFile();
 			foreach (var typeDef in unresolvedTypeDefinitions)
 				unresolvedFile.TopLevelTypeDefinitions.Add(typeDef);
 			return CreateCompilation(unresolvedFile);