🚀 go-pugleaf

xdispepoch.c can deref a null ptr and cause core dumps.

This is very similar to a previously fixed problem 
in xdispepoch.c.

Patch:


*** xdispepoch.c~	Mon Apr 27 10:08:02 1992
--- xdispepoch.c	Thu Apr 30 14:45:38 1992
***************
*** 1980,1990 ****
    {
      int i;
      struct line_header *l = XLINE(w->lines);
!     struct char_block *cb;
  
      i = ws->cursor_y;
      while (l && i--) l = l->next;
!     cb = l->body;
      i = ws->cursor_x;
      while (cb && i--) cb = cb->next;
  
--- 1980,1991 ----
    {
      int i;
      struct line_header *l = XLINE(w->lines);
!     struct char_block *cb = 0;
  
      i = ws->cursor_y;
      while (l && i--) l = l->next;
!     if (l)
!         cb = l->body;
      i = ws->cursor_x;
      while (cb && i--) cb = cb->next;
  
--
--tbennett     tony.bennett@East.Sun.COM   mailstop: RTP-NC