FilePath: Remove most of ToWStringHack, adding a LossyDisplayName()

chrome/browser/download/download_item.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/download/download_item.h"
 
 #include "base/basictypes.h"
 #include "base/file_util.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
@@ skipping 468 matching lines @@
   // A good test case would be:
   //   "/\xe4\xbd\xa0\xe5\xa5\xbd\xe4\xbd\xa0\xe5\xa5\xbd",
   //   L"/\x4f60\x597d\x4f60\x597d",
   //   "/%E4%BD%A0%E5%A5%BD%E4%BD%A0%E5%A5%BD"
   PrefService* prefs = download_manager_->profile()->GetPrefs();
   std::string languages(prefs->GetString(prefs::kAcceptLanguages));
   string16 url_formatted(l10n_util::ToLower(net::FormatUrl(url_, languages)));
   if (url_formatted.find(query) != string16::npos)
     return true;
 
-  string16 path(l10n_util::ToLower(WideToUTF16(full_path().ToWStringHack())));
+  string16 path(l10n_util::ToLower(full_path().LossyDisplayName()));
   if (path.find(query) != std::wstring::npos)

[Mark Mentovai, 2011/02/04 19:26:58]

string16::find doesn’t seem like the right way to search or compare UTF-16 text.

[evanm, 2011/02/04 19:37:12]

I guess for strict substring it's ok, because extension bytes never match
non-extension bytes?  (... here, search for "string searches" on
http://en.wikipedia.org/wiki/UTF-16/UCS-2 )

In any case, I am not changing the logic here.  Though I might as well fix this
to use string16::npos while I'm here.

[Avi (use Gerrit), 2011/02/04 19:42:32]

For strict substring, this is valid.

[Mark Mentovai, 2011/02/04 19:49:32]

evanm wrote:
I think that discussion only considers whether UTF-16 surrogates pose a problem
for string searches. They don’t. But Unicode’s full of other surprises. What
about composite characters? Are the strings already canonical? Should 0065 0301
compare equal to 00e9?

http://en.wikipedia.org/wiki/Unicode#Ready-made_versus_composite_characters

http://en.wikipedia.org/wiki/Canonical_equivalence

[evanm, 2011/02/04 19:58:50]

Good point.  Filed a bug, added a link.

     return true;
 
   return false;
 }
 
 void DownloadItem::SetFileCheckResults(const FilePath& path,
                                        bool is_dangerous,
                                        int path_uniquifier,
                                        bool prompt,
                                        bool is_extension_install,
@@ skipping 77 matching lines @@
         target_name_.value().c_str(),
         full_path().value().c_str());
   } else {
     description += base::StringPrintf(" url = \"%s\"", url().spec().c_str());
   }
 
   description += " }";
 
   return description;
 }