PVS-Studio warning V530 for Chromium

std::wstring url_;

HRESULT ProtData::ReportProgress(IInternetProtocolSink* delegate,
                                 ULONG status_code,
                                 LPCWSTR status_text)
{
  ...
  case BINDSTATUS_REDIRECTING:
    url_.empty();
    if (status_text)
      url_ = status_text;
    break;
  ...
}

This is what should have been written here: url_.clear();

This suspicious code was found in Chromium project by PVS-Studio static code analyzer.
Warning message is:
V530 The return value of function 'empty' is required to be utilized.  chrome_frame_ie  protocol_sink_wrap.cc  399

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/