--- a/netwerk/base/src/nsFileStreams.cpp
+++ b/netwerk/base/src/nsFileStreams.cpp
@@ -731,21 +731,21 @@ nsSafeFileOutputStream::Finish()
             // in writing to the target file), there is nothing more to do.
 #ifdef DEBUG      
             PRBool equal;
             if (NS_FAILED(mTargetFile->Equals(mTempFile, &equal)) || !equal)
                 NS_ERROR("mTempFile not equal to mTargetFile");
 #endif
         }
         else {
-            nsCAutoString targetFilename;
-            rv = mTargetFile->GetNativeLeafName(targetFilename);
+            nsAutoString targetFilename;
+            rv = mTargetFile->GetLeafName(targetFilename);
             if (NS_SUCCEEDED(rv)) {
                 // This will replace target.
-                rv = mTempFile->MoveToNative(nsnull, targetFilename);
+                rv = mTempFile->MoveTo(nsnull, targetFilename);
                 if (NS_FAILED(rv))
                     mTempFile->Remove(PR_FALSE);
             }
         }
     }
     else {
         mTempFile->Remove(PR_FALSE);
 

new file mode 100644
--- /dev/null
+++ b/netwerk/test/unit/test_safeoutputstream.js
@@ -0,0 +1,83 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * the Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2011
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Boris Zbarsky <bzbarsky@mit.edu> (original author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cr = Components.results;
+
+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");
+}