Some terminals don't correctly clear their let's-wrap flag after changing the

scroll region (which moves the cursor to 0,0). This means that if the cursor
was at the edge of the screen, any further output after scroll region change
incorrectly causes a line wrap. Add a workaround to move the cursor to position
0 if it is at the screen edge before changing scroll region.

1 files changed, 9 insertions, 0 deletions

diff --git a/tty.c b/tty.c
index ee725edf..177648b7 100644
--- a/tty.c
+++ b/tty.c
@@ -955,6 +955,15 @@ tty_region(struct tty *tty, u_int rupper, u_int rlower)
 	tty->rupper = rupper;
 	tty->rlower = rlower;
 
+	/*
+	 * Some terminals (such as PuTTY) do not correctly reset the cursor to
+	 * 0,0 if it is beyond the last column (they do not reset their wrap
+	 * flag so further output causes a line feed). As a workaround, do an
+	 * explicit move to 0 first.
+	 */
+	if (tty->cx >= tty->sx)
+		tty_cursor(tty, 0, tty->cy);
+
 	tty->cx = 0;
 	tty->cy = 0;