anchor.diff:  !    s_buffer(n:n) = c 
       buffer = buffer//c
       n = n + 1
  -    read(unit=vtk(rf)%u, iostat=E_IO) c
  +    read(unit=vtk(rf)%u, iostat=E_IO) c; if(E_IO /= 0) exit
     enddo
     !---------------------------------------------------------------------------------------------------------------------------------
     end function
  
positive.code:         rewind(unit=vtk(rf)%u, iostat=E_IO)
          np = 0
          do
            E_IO = read_record(s_buffer, cf=rf)
            s_buffer = trim(adjustl(Upper_Case(s_buffer)))
            if (index(s_buffer, '</'//trim(Upper_Case(vtk(rf)%topology))) > 0) exit !end of ASCII header section found
            if (index(s_buffer, '<PIECE') > 0) np = np + 1
  
negative.code:         rewind(unit=vtk(rf)%u, iostat=E_IO)
          read(unit=vtk(rf)%u,iostat=E_IO) c1
          do 
            read(unit=vtk(rf)%u,iostat=E_IO) c2; if(E_IO /= 0) exit
            if (iachar(c1)==10 .and. c2 =='_') exit
            c1 = c2
          enddo
  