PVS-Studio warning V579 for ffdshow

TprintPrefs::TprintPrefs(IffdshowBase *Ideci,
                         const TfontSettings *IfontSettings)
{
  // This doesn't seem to help after optimization.
  memset(this, 0, sizeof(this));
  dx = dy = 0;
  isOSD = false;
  xpos = ypos = 0;
  align = 0;
  linespacing = 0;
  sizeDx = 0;
  sizeDy = 0;
  ...
}

Super! As always, the compiler is to blame. This is what should have been written here: sizeof(*this).

This suspicious code was found in ffdshow project by PVS-Studio static code analyzer.
Warning message is:
V579 The memset function receives the pointer and its size as arguments. It is possibly a mistake. Inspect the third argument. tfont.cpp 44

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/