PVS-Studio warning V558 for Virtualdub

vdlist_iterator& operator--(int) {
  vdlist_iterator tmp(*this);
  mp = mp->mListNodePrev;
  return tmp;
}

This suspicious code was found in Virtualdub project by PVS-Studio static code analyzer.
Warning message is:
V558 Function returns the reference to temporary local object: tmp. VirtualDub vdstl.h 460

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/