From 2ed3f8db4482025446999461aab5a6ea36c9896a Mon Sep 17 00:00:00 2001
From: kzc <kzc@users.noreply.github.com>
Date: Wed, 2 Aug 2017 12:40:19 -0400
Subject: [PATCH] fix output of spread of a sequence (#2268)

fixes #2267
---
 lib/output.js            |  1 +
 test/compress/harmony.js | 47 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/lib/output.js b/lib/output.js
index ccd614d3..9198719d 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -689,6 +689,7 @@ function OutputStream(options) {
                                                                * ==> 20 (side effect, set a := 10 and b := 20) */
             || p instanceof AST_Arrow                         // x => (x, x)
             || p instanceof AST_DefaultAssign                 // x => (x = (0, function(){}))
+            || p instanceof AST_Expansion                     // [...(a, b)]
         ;
     });
 
diff --git a/test/compress/harmony.js b/test/compress/harmony.js
index 2f095383..2e8fe38b 100644
--- a/test/compress/harmony.js
+++ b/test/compress/harmony.js
@@ -757,3 +757,50 @@ object_spread_unsafe: {
         console.log(l, x);
     }
 }
+
+array_spread_of_sequence: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var a = [1];
+        console.log([...(a, a)]);
+        console.log([...a, a]);
+        console.log([...(a || a)]);
+        console.log([...a || a]);
+    }
+    expect: {
+        var o = [1];
+        console.log([...(o, o)]);
+        console.log([...o, o]);
+        console.log([...o || o]);
+        console.log([...o || o]);
+    }
+    expect_stdout: [
+        "[ 1 ]",
+        "[ 1, [ 1 ] ]",
+        "[ 1 ]",
+        "[ 1 ]",
+    ]
+    node_version: ">=6"
+}
+
+object_spread_of_sequence: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var a = {x: 1};
+        console.log({ ...(a, a) });
+        console.log({ ...a, a });
+        console.log({ ...(a || a) });
+        console.log({ ...a || a });
+    }
+    expect: {
+        var o = { x: 1 };
+        console.log({ ...(o, o) });
+        console.log({ ...o, a: o });
+        console.log({ ...o || o });
+        console.log({ ...o || o });
+    }
+}