Check for empty paths in path_util

chrome/browser/extensions/path_util.cc

 // Copyright 2014 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/extensions/path_util.h"
 
 #include "base/path_service.h"
 #include "base/strings/sys_string_conversions.h"
 
 #if defined(OS_MACOSX)
 #include <CoreFoundation/CoreFoundation.h>
 #include "base/mac/foundation_util.h"
 #endif
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/file_manager/filesystem_api_util.h"
 #endif
 
 namespace extensions {
 namespace path_util {
 
 #if defined(OS_MACOSX)
 namespace {
 
 // Retrieves the localized display name for the base name of the given path.
 // If the path is not localized, this will just return the base name.
 std::string GetDisplayBaseName(const base::FilePath& path) {

[not at google - send to devlin, 2014/08/04 23:39:07]

put specific OS_MACOSX namespace around this function

   base::ScopedCFTypeRef<CFURLRef> url(CFURLCreateFromFileSystemRepresentation(
       NULL, (const UInt8*)path.value().c_str(), path.value().length(), true));
   if (!url)
     return path.BaseName().value();
 
   CFStringRef str;
   if (LSCopyDisplayNameForURL(url, &str) != noErr)
     return path.BaseName().value();
 
   std::string result(base::SysCFStringRefToUTF8(str));
   CFRelease(str);
   return result;
 }
 
 }  // namespace
 
 base::FilePath PrettifyPath(const base::FilePath& source_path) {

[not at google - send to devlin, 2014/08/04 23:39:07]

declare this function then do the empty-path check and the other parts which are
common to every implementation (getting the home directory). then ifdef out only
the important parts.

e.g.

base::FilePath PrettifyPath(..) {
  if (source_path.empty())
    return base::FilePath();

  base::FilePath home_path;
  if (!PathService::Get(base::DIR_HOME, &home_path))
    return base::FilePath();

#if defined(OS_MACOSX)
  ...
#else  // defined(OS_MAXOSX)
  ...
#endif
}

+  if (source_path.empty())
+    return base::FilePath();
   base::FilePath home_path;
   PathService::Get(base::DIR_HOME, &home_path);
   DCHECK(source_path.IsAbsolute());
 
   // Break down the incoming path into components, and grab the display name
   // for every component. This will match app bundles, ".localized" folders,
   // and localized subfolders of the user's home directory.
   // Don't grab the display name of the first component, i.e., "/", as it'll
   // show up as the HDD name.
   std::vector<base::FilePath::StringType> components;
   source_path.GetComponents(&components);
   base::FilePath display_path = base::FilePath(components[0]);
   base::FilePath actual_path = display_path;
   for (std::vector<base::FilePath::StringType>::iterator i =
            components.begin() + 1; i != components.end(); ++i) {
     actual_path = actual_path.Append(*i);
     if (actual_path == home_path) {
       display_path = base::FilePath("~");
       home_path = base::FilePath();
       continue;
     }
     std::string display = GetDisplayBaseName(actual_path);
     display_path = display_path.Append(display);
   }
   DCHECK_EQ(actual_path.value(), source_path.value());
   return display_path;
 }
 #else   // defined(OS_MACOSX)
 base::FilePath PrettifyPath(const base::FilePath& source_path) {
+  if (source_path.empty())
+    return base::FilePath();
   base::FilePath home_path;
   base::FilePath display_path = base::FilePath::FromUTF8Unsafe("~");
   if (PathService::Get(base::DIR_HOME, &home_path) &&
       home_path.AppendRelativePath(source_path, &display_path))
     return display_path;
   return source_path;
 }
 #endif  // defined(OS_MACOSX)
 
 }  // namespace path_util
 }  // namespace extensions