From a645dd4b91f12b4c07bb53d9a7946a6796e2a3f5 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@mozilla.com>
Date: Fri, 4 Mar 2011 18:39:38 -0800
Subject: [PATCH] Bug 634666 - File streams perform disk I/O when being
 initialized. r=philikon a=blocking-fennec

---
 services/sync/modules/util.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/services/sync/modules/util.js b/services/sync/modules/util.js
index a774f0e144a6..4c2fedbc6e97 100644
--- a/services/sync/modules/util.js
+++ b/services/sync/modules/util.js
@@ -1140,7 +1140,8 @@ let Utils = {
 
     let fos = Cc["@mozilla.org/network/safe-file-output-stream;1"]
                 .createInstance(Ci.nsIFileOutputStream);
-    fos.init(file, MODE_WRONLY | MODE_CREATE | MODE_TRUNCATE, PERMS_FILE, 0);
+    fos.init(file, MODE_WRONLY | MODE_CREATE | MODE_TRUNCATE, PERMS_FILE,
+             fos.DEFER_OPEN || 0);
     let is = this._utf8Converter.convertToInputStream(out);
     NetUtil.asyncCopy(is, fos, function (result) {
       if (typeof callback == "function") {