fix tty crashes for empty news file

- menu-window code could access a null pointer when there was no data
- menu-window code can't handle empty contents, because there's no place
  to position the cursor, so force text mode
- still looked ugly, so added a check to avoid displaying anything if
  the file was empty

diff --git a/win/tty/wintty.c b/win/tty/wintty.c
index 344d5a4e0fd5f7a6f3e21ef23faaa19e30c19de8..ced54c1ed1be90ab60ba80ef2f72b757017948e0 100644 (file)
--- a/win/tty/wintty.c
+++ b/win/tty/wintty.c
@@ -1243,8 +1243,10 @@ struct WinDesc *cw;
            if (cw->npages > 1)
                Sprintf(cw->morestr, "(%d of %d)",
                        curr_page + 1, (int) cw->npages);
-           else
+           else if (msave)
                Strcpy(cw->morestr, msave);
+           else
+               Strcpy(cw->morestr, defmorestr);
 
            tty_curs(window, 1, page_lines);
            cl_end();
@@ -1517,7 +1519,7 @@ tty_display_nhwindow(window, blocking)
        } else
            tty_clear_nhwindow(WIN_MESSAGE);
 
-       if (cw->data)
+       if (cw->data || !cw->maxrow)
            process_text_window(window, cw);
        else
            process_menu_window(window, cw);
@@ -1910,6 +1912,8 @@ boolean complain;
            } else if(u.ux) docrt();
        } else {
            winid datawin = tty_create_nhwindow(NHW_TEXT);
+           boolean empty = TRUE;
+
            if(complain
 #ifndef NO_TERMS
                && nh_CD
@@ -1926,11 +1930,12 @@ boolean complain;
                if ((cr = index(buf, '\r')) != 0) *cr = 0;
 #endif
                if (index(buf, '\t') != 0) (void) tabexpand(buf);
+               empty = FALSE;
                tty_putstr(datawin, 0, buf);
                if(wins[datawin]->flags & WIN_CANCELLED)
                    break;
            }
-           tty_display_nhwindow(datawin, FALSE);
+           if (!empty) tty_display_nhwindow(datawin, FALSE);
            tty_destroy_nhwindow(datawin);
            (void) dlb_fclose(f);
        }