void OccViewer::_cppRegisterFont (const std::string& theFontFile,
                                  const std::string& theFontName,
                                  bool               theToOverride)
{
  if (Handle (Font_SystemFont) aFont = Font_FontMgr::GetInstance()->CheckFont (theFontFile.c_str()))
  {
    if (!theFontName.empty())
    {
      Handle (Font_SystemFont) aFont2 = aFont;
      aFont                           = new Font_SystemFont (theFontName.c_str());
      for (int anAspectIter = 0; anAspectIter < Font_FontAspect_NB; ++anAspectIter)
      {
        aFont->SetFontPath ((Font_FontAspect)anAspectIter,
                            aFont2->FontPath ((Font_FontAspect)anAspectIter),
                            aFont2->FontFaceId ((Font_FontAspect)anAspectIter));
      }
    }
    Font_FontMgr::GetInstance()->RegisterFont (aFont, theToOverride);
    //const Handle (OccViewer)& anInstance = Instance();
    //const Handle (Prs3d_Drawer)& aDefaultDrawer = anInstance->Context()->DefaultDrawer();
    //Handle (Prs3d_TextAspect)    aTextAspect    = aDefaultDrawer->TextAspect();
    //aTextAspect->Aspect()->SetFont (aFont->FontName());
  }
  else
  {
    Message::DefaultMessenger()->SendFail() << "Error: font '" << theFontFile << "' is not found";
  }
}

2. Run provided code to reach out of memory

  auto findAndCreate = []()
  {
    Font_FTFontParams aFontParams;
    aFontParams.PointSize   = 10;
    aFontParams.Resolution  = 96;
    aFontParams.FontHinting = Font_Hinting_Off;

    Handle (Font_FTFont) aFont = Font_FTFont::FindAndCreate ("serif",
                                                             Font_FontAspect_Regular,
                                                             aFontParams);
  };

  for (int i = 0; i < 100; i++)
  {
    findAndCreate();
  }