void FormatStringWithHyphens(base::string16* text) {
  struct HyphenPosition {
    HyphenPosition() : position(0), next_whitespace_position(0) {}
    size_t position;
    size_t next_whitespace_position;  // 0 for none
  };
  std::vector<HyphenPosition> hyphen_positions;
  HyphenPosition current_hyphen_position;
  bool current_hyphen_position_is_valid = false;
  const base::char16 kPdfiumHyphenEOL = 0xfffe;

  for (size_t i = 0; i < text->size(); ++i) {
    const base::char16& current_char = (*text)[i];
    if (current_char == kPdfiumHyphenEOL) {
      if (current_hyphen_position_is_valid)
        hyphen_positions.push_back(current_hyphen_position);
      current_hyphen_position = HyphenPosition();
      current_hyphen_position.position = i;
      current_hyphen_position_is_valid = true;
    } else if (base::IsUnicodeWhitespace(current_char)) {
      if (current_hyphen_position_is_valid) {
        if (current_char != L'\r' && current_char != L'\n')
          current_hyphen_position.next_whitespace_position = i;
        hyphen_positions.push_back(current_hyphen_position);
        current_hyphen_position_is_valid = false;
      }
    }
  }
  if (current_hyphen_position_is_valid)
    hyphen_positions.push_back(current_hyphen_position);

  while (!hyphen_positions.empty()) {
    static const base::char16 kCr[] = {L'\r', L'\0'};
    const HyphenPosition& position = hyphen_positions.back();
    if (position.next_whitespace_position != 0) {
      (*text)[position.next_whitespace_position] = L'\n';
      text->insert(position.next_whitespace_position, kCr);
    }
    text->erase(position.position, 1);
    hyphen_positions.pop_back();
  }

  static const base::char16 kSpaceCrCn[] = {L' ', L'\r', L'\n', L'\0'};
  static const base::char16 kCrCn[] = {L'\r', L'\n', L'\0'};
  base::ReplaceSubstringsAfterOffset(text, 0, kSpaceCrCn, kCrCn);
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.