Win: Don't give some downloads duplicate extensions like .arj.arj...

chrome/browser/views/shell_dialogs_win_unittest.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/shell_dialogs.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(AppendExtensionIfNeeded, EndingInPeriod_ExtensionAppended) {
   const std::wstring filename = L"sample.txt.";
   const std::wstring filter_selected = L"*.txt";
@@ skipping 52 matching lines @@
 TEST(AppendExtensionIfNeeded, AllFilesFilter_NoExtensionAppended) {
   const std::wstring filename = L"sample.unknown-mime-type";
   const std::wstring filter_selected = L"*.*";
   const std::wstring suggested_ext;
 
   const std::wstring actual_filename = AppendExtensionIfNeeded(filename,
       filter_selected, suggested_ext);
 
   ASSERT_EQ(L"sample.unknown-mime-type", actual_filename);
 }
+
+TEST(AppendExtensionIfNeeded, StripsDotsForUnknownSelectedMimeType) {
+  const std::wstring filename = L"product";
+  const std::wstring filter_selected = L"*.unknown-extension.";
+  const std::wstring suggested_ext = L"html";
+
+  const std::wstring actual_filename = AppendExtensionIfNeeded(filename,
+      filter_selected, suggested_ext);
+
+  ASSERT_EQ(L"product.html", actual_filename);
+}
+
+TEST(AppendExtensionIfNeeded, EqualToExtension_NoDoubleExtension) {
+  // Make sure we don't add a duplicate extension like .tbl.tbl for
+  // files that the system doesn't have a mime type for.
+  const std::wstring filename = L"product.tbl";
+  const std::wstring filter_selected = L"*.tbl";
+  const std::wstring suggested_ext = L"tbl";
+
+  const std::wstring actual_filename = AppendExtensionIfNeeded(filename,
+      filter_selected, suggested_ext);
+
+  ASSERT_EQ(L"product.tbl", actual_filename);
+}