Addressed CR feedback.

src/compiler/checker.ts

@@ -3461,11 +3461,14 @@ module ts {
         }
 
         function checkThisExpression(node: Node): Type {
-            var container = getThisContainerOrArrowFunction(node);
+            // Stop at the first arrow function so that we can
+            // tell whether 'this' needs to be captured.
+            var container = getThisContainer(node, /* includeArrowFunctions */ true);
             var needToCaptureLexicalThis = false;
-            // skip arrow functions
-            while (container.kind === SyntaxKind.ArrowFunction) {
-                container = getThisContainerOrArrowFunction(container);
+
+            // Now skip arrow functions to get the "real" owner of 'this'.
+            if (container.kind === SyntaxKind.ArrowFunction) {
+                container = getThisContainer(container, /* includeArrowFunctions */ false);
                 needToCaptureLexicalThis = true;
             }
 

src/compiler/parser.ts

@@ -407,13 +407,18 @@ module ts {
         }
     }
 
-    export function getThisContainerOrArrowFunction(node: Node): Node {
+    export function getThisContainer(node: Node, includeArrowFunctions: boolean): Node {
         while (true) {
             node = node.parent;
             if (!node) {
                 return node;
             }
             switch (node.kind) {
+                case SyntaxKind.ArrowFunction:
+                    if (!includeArrowFunctions) {
+                        continue;
+                    }
+                // Fall through
                 case SyntaxKind.FunctionDeclaration:
                 case SyntaxKind.FunctionExpression:
                 case SyntaxKind.ModuleDeclaration:
@@ -424,20 +429,11 @@ module ts {
                 case SyntaxKind.SetAccessor:
                 case SyntaxKind.EnumDeclaration:
                 case SyntaxKind.SourceFile:
-                case SyntaxKind.ArrowFunction:
                     return node;
             }
         }
     }
 
-    export function getThisContainer(node: Node): Node {
-        do {
-            node = getThisContainerOrArrowFunction(node);
-        } while (node.kind === SyntaxKind.ArrowFunction);
-
-        return node;
-    }
-
     export function hasRestParameters(s: SignatureDeclaration): boolean {
         return s.parameters.length > 0 && (s.parameters[s.parameters.length - 1].flags & NodeFlags.Rest) !== 0;
     }