From 339bf824816fd2e524859d1ea8cfb295201322ab Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Fri, 2 Jan 2015 22:22:01 +1100
Subject: [PATCH] avoid printing comments if they've already been output -
 fixes #365

---
 CHANGELOG.md                     | 4 ++++
 lib/6to5/generation/generator.js | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5647afd968..3cf0861234 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 Gaps between patch versions are faulty/broken releases.
 
+## 2.4.5
+
+ * Avoid printing comments if they've already been output.
+
 ## 2.4.4
 
  * Add `module` type to browser build `<script>` handler.
diff --git a/lib/6to5/generation/generator.js b/lib/6to5/generation/generator.js
index 2fb74be764..2f94186b3e 100644
--- a/lib/6to5/generation/generator.js
+++ b/lib/6to5/generation/generator.js
@@ -274,14 +274,21 @@ CodeGenerator.prototype._printComments = function (comments) {
   var self = this;
 
   _.each(comments, function (comment) {
+    var skip = false;
+
     // find the original comment in the ast and set it as displayed
     _.each(self.ast.comments, function (origComment) {
       if (origComment.start === comment.start) {
+        // comment has already been output
+        if (origComment._displayed) skip = true;
+
         origComment._displayed = true;
         return false;
       }
     });
 
+    if (skip) return;
+
     // whitespace before
     self.newline(self.whitespace.getNewlinesBefore(comment));