PVS-Studio warning V507 for Scilab

int sci_champ_G(....)
{
  ....
  char * strf = NULL ;
  ....
  if ( isDefStrf( strf ) )
  {
    char strfl[4];
    strcpy(strfl,DEFSTRFN);
    strf = strfl;
    if ( !isDefRect( rect ) )
    {
      strf[1]='5';
    }
  }

  (*func)(stk(l1 ),stk(l2 ),stk(l3 ),stk(l4 ),
    &m3,&n3,strf,rect, arfact, 4L);
  ....
}

This suspicious code was found in Scilab project by PVS-Studio static code analyzer.
Warning message is:
V507 Pointer to local array 'strfl' is stored outside the scope of this array. Such a pointer will become invalid. sci_champ.c 103

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/