From 96767e2f355647d8beba8334d4f5080e489b3328 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lauren=C5=A3iu=20Macovei?=
 <laurentiu.macovei@dotnetwise.com>
Date: Thu, 16 Oct 2014 22:27:07 +0300
Subject: [PATCH] Fixes #563 Fixes #152 Somehow addresses #145 by preserving
 the original sources in the inSourceMap (if they are there)

---
 lib/sourcemap.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/sourcemap.js b/lib/sourcemap.js
index 663ef12e..4a314931 100644
--- a/lib/sourcemap.js
+++ b/lib/sourcemap.js
@@ -53,11 +53,13 @@ function SourceMap(options) {
         orig_line_diff : 0,
         dest_line_diff : 0,
     });
-    var generator = new MOZ_SourceMap.SourceMapGenerator({
+    var orig_map = options.orig && new MOZ_SourceMap.SourceMapConsumer(options.orig);
+    var generator = options.orig
+		? MOZ_SourceMap.SourceMapGenerator.fromSourceMap(orig_map)
+		: new MOZ_SourceMap.SourceMapGenerator({
         file       : options.file,
         sourceRoot : options.root
     });
-    var orig_map = options.orig && new MOZ_SourceMap.SourceMapConsumer(options.orig);
     function add(source, gen_line, gen_col, orig_line, orig_col, name) {
         if (orig_map) {
             var info = orig_map.originalPositionFor({