Conformance: ignore {delete,insert} line while outside the scrolling region.

I noticed a small inconsistency in delete and insert line between xterm
and libteken. libteken allows these actions to happen while the cursor
is placed outside the scrolling region, while xterm does not.

This behaviour seems to be VT100-like. Confirmation:

	http://www.vt100.net/docs/vt102-ug/chapter5.html
	"This sequence is ignored when cursor is outside scrolling region."

MFC after:	1 month

1 files changed, 10 insertions, 0 deletions

diff --git a/sys/teken/teken_subr.h b/sys/teken/teken_subr.h
index 9e84b9c..7d8cd0c 100644
--- a/sys/teken/teken_subr.h
+++ b/sys/teken/teken_subr.h
@@ -397,6 +397,11 @@ teken_subr_delete_line(teken_t *t, unsigned int nrows)
 {
 	teken_rect_t tr;
 
+	/* Ignore if outside scrolling region. */
+	if (t->t_cursor.tp_row < t->t_scrollreg.ts_begin ||
+	    t->t_cursor.tp_row >= t->t_scrollreg.ts_end)
+		return;
+
 	tr.tr_begin.tp_col = 0;
 	tr.tr_end.tp_row = t->t_scrollreg.ts_end;
 	tr.tr_end.tp_col = t->t_winsize.tp_col;
@@ -656,6 +661,11 @@ teken_subr_insert_line(teken_t *t, unsigned int nrows)
 {
 	teken_rect_t tr;
 
+	/* Ignore if outside scrolling region. */
+	if (t->t_cursor.tp_row < t->t_scrollreg.ts_begin ||
+	    t->t_cursor.tp_row >= t->t_scrollreg.ts_end)
+		return;
+
 	tr.tr_begin.tp_row = t->t_cursor.tp_row;
 	tr.tr_begin.tp_col = 0;
 	tr.tr_end.tp_col = t->t_winsize.tp_col;