From 63cf58bd09289fd4be743fc4267c839f9abf8d9e Mon Sep 17 00:00:00 2001
From: Ron Buckton <rbuckton@microsoft.com>
Date: Tue, 22 Mar 2016 16:49:16 -0700
Subject: [PATCH] Fix extra slice in array with spread

---
 src/compiler/transformers/es6.ts | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/compiler/transformers/es6.ts b/src/compiler/transformers/es6.ts
index b53b3602556..84213239371 100644
--- a/src/compiler/transformers/es6.ts
+++ b/src/compiler/transformers/es6.ts
@@ -1467,7 +1467,7 @@ namespace ts {
                 return createFunctionApply(
                     visitNode(target, visitor, isExpression),
                     visitNode(thisArg, visitor, isExpression),
-                    transformAndSpreadElements(node.arguments, /*needsUniqueCopy*/ false, /*multiLine*/ false)
+                    transformAndSpreadElements(node.arguments, /*needsUniqueCopy*/ false, /*multiLine*/ false, /*hasTrailingComma*/ false)
                 );
             }
             else {
@@ -1510,7 +1510,7 @@ namespace ts {
                 createFunctionApply(
                     visitNode(target, visitor, isExpression),
                     thisArg,
-                    transformAndSpreadElements(createNodeArray([createVoidZero(), ...node.arguments]), /*needsUniqueCopy*/ false, /*multiLine*/ false)
+                    transformAndSpreadElements(createNodeArray([createVoidZero(), ...node.arguments]), /*needsUniqueCopy*/ false, /*multiLine*/ false, /*hasTrailingComma*/ false)
                 ),
                 []
             );
@@ -1523,7 +1523,7 @@ namespace ts {
          * @param needsUniqueCopy A value indicating whether to ensure that the result is a fresh array.
          * @param multiLine A value indicating whether the result should be emitted on multiple lines.
          */
-        function transformAndSpreadElements(elements: NodeArray<Expression>, needsUniqueCopy: boolean, multiLine: boolean, hasTrailingComma?: boolean): Expression {
+        function transformAndSpreadElements(elements: NodeArray<Expression>, needsUniqueCopy: boolean, multiLine: boolean, hasTrailingComma: boolean): Expression {
             // [source]
             //      [a, ...b, c]
             //
@@ -1540,7 +1540,8 @@ namespace ts {
             );
 
             if (segments.length === 1) {
-                return needsUniqueCopy && isSpreadElementExpression(elements[0])
+                const firstElement = elements[0];
+                return needsUniqueCopy && isSpreadElementExpression(firstElement) && firstElement.expression.kind !== SyntaxKind.ArrayLiteralExpression
                     ? createArraySlice(segments[0])
                     : segments[0];
             }