From d9bc6f303c7649811dedd1b5646c83df89c24588 Mon Sep 17 00:00:00 2001
From: Anthony Van de Gejuchte <anthonyvdgent@gmail.com>
Date: Sun, 3 Jul 2016 20:17:03 +0200
Subject: [PATCH] Fix output arrow function with 1 param with default value

Fixes #1090
---
 lib/output.js          | 2 +-
 test/compress/arrow.js | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/output.js b/lib/output.js
index 60c8dad8..e309f5bd 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -909,7 +909,7 @@ function OutputStream(options) {
             parent instanceof AST_Unary ||
             parent instanceof AST_Call;
         if (needs_parens) { output.print("(") }
-        if (self.argnames.length === 1 && self.argnames[0] instanceof AST_Symbol) {
+        if (self.argnames.length === 1 && self.argnames[0] instanceof AST_Symbol && !self.argnames[0].default) {
             self.argnames[0].print(output);
         } else {
             output.with_parens(function(){
diff --git a/test/compress/arrow.js b/test/compress/arrow.js
index c5838537..1a8b17ed 100644
--- a/test/compress/arrow.js
+++ b/test/compress/arrow.js
@@ -82,4 +82,11 @@ arrow_functions_with_body: {
             b.join();
         };
     }
-}
\ No newline at end of file
+}
+
+arrow_function_with_single_parameter_with_default: {
+    input: {
+        var foo = (a = 0) => doSomething(a);
+    }
+    expect_exact: "var foo=(a=0)=>doSomething(a);"
+}