From 719705faf66ed4eeee49abda50fbf4ed914c81d4 Mon Sep 17 00:00:00 2001
From: Ron Buckton <rbuckton@microsoft.com>
Date: Wed, 20 Apr 2016 18:36:05 -0700
Subject: [PATCH] Adds source maps for captured this, skips source map for
 synthetic return token in arrow.

---
 src/compiler/printer.ts          | 4 ++--
 src/compiler/transformers/es6.ts | 7 +++++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/compiler/printer.ts b/src/compiler/printer.ts
index 89d7ef04140..62b73924da9 100644
--- a/src/compiler/printer.ts
+++ b/src/compiler/printer.ts
@@ -1546,7 +1546,7 @@ const _super = (function (geti, seti) {
                         const savedTempFlags = tempFlags;
                         tempFlags = 0;
                         emitSignatureHead(node);
-                        emitBlockFunctionBodyAndEndLexicalEnvironment(node, body);
+                        emitBlockFunctionBody(node, body);
                         if (indentedFlag) {
                             decreaseIndent();
                         }
@@ -1610,7 +1610,7 @@ const _super = (function (geti, seti) {
                 return true;
             }
 
-            function emitBlockFunctionBodyAndEndLexicalEnvironment(parentNode: Node, body: Block) {
+            function emitBlockFunctionBody(parentNode: Node, body: Block) {
                 // TODO(rbuckton): This should be removed once source maps are aligned with the old
                 //                 emitter and new baselines are taken. This exists solely to
                 //                 align with the old emitter.
diff --git a/src/compiler/transformers/es6.ts b/src/compiler/transformers/es6.ts
index fe48fed049a..ceff4d0db50 100644
--- a/src/compiler/transformers/es6.ts
+++ b/src/compiler/transformers/es6.ts
@@ -1063,7 +1063,8 @@ namespace ts {
                                 "_this",
                                 createThis()
                             )
-                        ])
+                        ]),
+                        /*location*/ node
                     )
                 );
             }
@@ -1343,7 +1344,9 @@ namespace ts {
 
                 const expression = visitNode(body, visitor, isExpression);
                 if (expression) {
-                    statements.push(createReturn(expression, /*location*/ statementsLocation));
+                    const returnStatement = createReturn(expression, /*location*/ statementsLocation);
+                    setNodeEmitFlags(returnStatement, NodeEmitFlags.NoTokenSourceMaps);
+                    statements.push(returnStatement);
                 }
             }