See <https://sourceforge.net/p/libmwaw/tickets/6/attachment/minimal.patch>:
--- src/lib/MWAWPictMac.cxx
+++ src/lib/MWAWPictMac.cxx
@@ -1060,7 +1060,6 @@
     if (type5==WP_NONE) return;
     else m_types.push_back(type5);
   }
-  virtual ~OpCode() {}
 
   /** tries to read the data in the file
    *