diff -r 000000000000 -r 6474c204b198 netwerk/test/unit/test_safeoutputstream.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netwerk/test/unit/test_safeoutputstream.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,66 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+function write_atomic(file, str) {
+    var stream = Cc["@mozilla.org/network/atomic-file-output-stream;1"]
+                   .createInstance(Ci.nsIFileOutputStream);
+    stream.init(file, -1, -1, 0);
+    do {
+        var written = stream.write(str, str.length);
+        if (written == str.length)
+            break;
+        str = str.substring(written);
+    } while (1);
+    stream.QueryInterface(Ci.nsISafeOutputStream).finish();
+    stream.close();
+}
+
+function write(file, str) {
+    var stream = Cc["@mozilla.org/network/safe-file-output-stream;1"]
+                   .createInstance(Ci.nsIFileOutputStream);
+    stream.init(file, -1, -1, 0);
+    do {
+        var written = stream.write(str, str.length);
+        if (written == str.length)
+            break;
+        str = str.substring(written);
+    } while (1);
+    stream.QueryInterface(Ci.nsISafeOutputStream).finish();
+    stream.close();
+}
+
+function checkFile(file, str) {
+    var stream = Cc["@mozilla.org/network/file-input-stream;1"]
+                   .createInstance(Ci.nsIFileInputStream);
+    stream.init(file, -1, -1, 0);
+
+    var scriptStream = Cc["@mozilla.org/scriptableinputstream;1"]
+                         .createInstance(Ci.nsIScriptableInputStream);
+    scriptStream.init(stream);
+
+    do_check_eq(scriptStream.read(scriptStream.available()), str);
+    scriptStream.close();
+}
+
+function run_test()
+{
+    var filename = "\u0913";
+    var file = Cc["@mozilla.org/file/directory_service;1"]
+                 .getService(Ci.nsIProperties)
+                 .get("TmpD", Ci.nsIFile);
+    file.append(filename);
+
+    write(file, "First write");
+    checkFile(file, "First write");
+
+    write(file, "Second write");
+    checkFile(file, "Second write");
+
+    write_atomic(file, "First write: Atomic");
+    checkFile(file, "First write: Atomic");
+
+    write_atomic(file, "Second write: Atomic");
+    checkFile(file, "Second write: Atomic");
+}