Method AppendRelativePath

src/butil/files/file_path.cc:259–301

}

bool FilePath::AppendRelativePath(const FilePath& child,
                                  FilePath* path) const {
  std::vector<StringType> parent_components;
  std::vector<StringType> child_components;
  GetComponents(&parent_components);
  child.GetComponents(&child_components);

  if (parent_components.empty() ||
      parent_components.size() >= child_components.size())
    return false;

  std::vector<StringType>::const_iterator parent_comp =
      parent_components.begin();
  std::vector<StringType>::const_iterator child_comp =
      child_components.begin();

#if defined(FILE_PATH_USES_DRIVE_LETTERS)
  // Windows can access case sensitive filesystems, so component
  // comparisions must be case sensitive, but drive letters are
  // never case sensitive.
  if ((FindDriveLetter(*parent_comp) != StringType::npos) &&
      (FindDriveLetter(*child_comp) != StringType::npos)) {
    if (!StartsWith(*parent_comp, *child_comp, false))
      return false;
    ++parent_comp;
    ++child_comp;
  }
#endif  // defined(FILE_PATH_USES_DRIVE_LETTERS)

  while (parent_comp != parent_components.end()) {
    if (*parent_comp != *child_comp)
      return false;
    ++parent_comp;
    ++child_comp;
  }

  if (path != NULL) {
    for (; child_comp != child_components.end(); ++child_comp) {
      *path = path->Append(*child_comp);
    }
  }
  return true;
}

// libgen's dirname and basename aren't guaranteed to be thread-safe and aren't
// guaranteed to not modify their input strings, and in fact are implemented