Fixes #2601, incorrect resolution of this/super

Author: rbuckton

src/compiler/checker.ts

@@ -5600,7 +5600,7 @@ module ts {
                 }
             }
 
-            if (container.kind === SyntaxKind.ComputedPropertyName) {
+            if (container && container.kind === SyntaxKind.ComputedPropertyName) {
                 error(node, Diagnostics.super_cannot_be_referenced_in_a_computed_property_name);
             }
             else if (isCallExpression) {

src/compiler/utilities.ts

@@ -526,6 +526,19 @@ module ts {
                     // the *body* of the container.
                     node = node.parent;
                     break;
+                case SyntaxKind.Decorator:
+                    // Decorators are always applied outside of the body of a class or method. 
+                    if (node.parent.kind === SyntaxKind.Parameter && isClassElement(node.parent.parent)) {
+                        // If the decorator's parent is a Parameter, we resolve the this container from
+                        // the grandparent class declaration.
+                        node = node.parent.parent;
+                    }
+                    else if (isClassElement(node.parent)) {
+                        // If the decorator's parent is a class element, we resolve the 'this' container
+                        // from the parent class declaration.
+                        node = node.parent;
+                    }
+                    break;
                 case SyntaxKind.ArrowFunction:
                     if (!includeArrowFunctions) {
                         continue;
@@ -568,6 +581,19 @@ module ts {
                     // the *body* of the container.
                     node = node.parent;
                     break;
+                case SyntaxKind.Decorator:
+                    // Decorators are always applied outside of the body of a class or method. 
+                    if (node.parent.kind === SyntaxKind.Parameter && isClassElement(node.parent.parent)) {
+                        // If the decorator's parent is a Parameter, we resolve the this container from
+                        // the grandparent class declaration.
+                        node = node.parent.parent;
+                    }
+                    else if (isClassElement(node.parent)) {
+                        // If the decorator's parent is a class element, we resolve the 'this' container
+                        // from the parent class declaration.
+                        node = node.parent;
+                    }
+                    break;
                 case SyntaxKind.FunctionDeclaration:
                 case SyntaxKind.FunctionExpression:
                 case SyntaxKind.ArrowFunction:
@@ -919,6 +945,7 @@ module ts {
             case SyntaxKind.MethodDeclaration:
             case SyntaxKind.GetAccessor:
             case SyntaxKind.SetAccessor:
+            case SyntaxKind.MethodSignature:
             case SyntaxKind.IndexSignature:
                 return true;
             default: