On xterm 271 and later, put the terminal into SCL 5 and use DECCRA for

scrolling the region in panes (if the large region check isn't
hit). With help from Ailin Nemui.

3 files changed, 44 insertions, 5 deletions

diff --git a/tmux.h b/tmux.h
index 5f2f3a44..8d0b680f 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1472,8 +1472,9 @@ void	tty_putc(struct tty *, u_char);
 void	tty_pututf8(struct tty *, const struct grid_utf8 *);
 void	tty_init(struct tty *, int, char *);
 int	tty_resize(struct tty *);
-int	tty_set_size(struct tty *tty, u_int sx, u_int sy);
+int	tty_set_size(struct tty *, u_int, u_int);
 void	tty_start_tty(struct tty *);
+void	tty_set_version(struct tty *, u_int);
 void	tty_stop_tty(struct tty *);
 void	tty_set_title(struct tty *, const char *);
 void	tty_update_mode(struct tty *, int, struct screen *);
diff --git a/tty-keys.c b/tty-keys.c
index 37265dce..c5b85ce1 100644
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -728,8 +728,7 @@ tty_keys_device(struct tty *tty, const char *buf, size_t len, size_t *size)
 		a = b = 0;
 
 	log_debug("received xterm version %u", b);
-	if (tty->xterm_version == 0)
-		tty->xterm_version = b;
+	tty_set_version(tty, b);
 
 	return (0);
 }
diff --git a/tty.c b/tty.c
index a36bf787..c9191a6a 100644
--- a/tty.c
+++ b/tty.c
@@ -177,7 +177,7 @@ tty_error_callback(
 void
 tty_init_termios(int fd, struct termios *orig_tio, struct bufferevent *bufev)
 {
-	struct termios	 tio;
+	struct termios	tio;
 
 	if (fd == -1 || tcgetattr(fd, orig_tio) != 0)
 		return;
@@ -235,6 +235,27 @@ tty_start_tty(struct tty *tty)
 }
 
 void
+tty_set_version(struct tty *tty, u_int version)
+{
+	if (tty->xterm_version != 0)
+		return;
+	tty->xterm_version = version;
+
+	if (tty->xterm_version > 270) {
+		tty_puts(tty, "\033[65;1\"p");
+
+		tty_putcode(tty, TTYC_RMACS);
+		memcpy(&tty->cell, &grid_default_cell, sizeof tty->cell);
+
+		tty->cx = UINT_MAX;
+		tty->cy = UINT_MAX;
+
+		tty->rupper = UINT_MAX;
+		tty->rlower = UINT_MAX;
+	}
+}
+
+void
 tty_stop_tty(struct tty *tty)
 {
 	struct winsize	ws;
@@ -276,6 +297,9 @@ tty_stop_tty(struct tty *tty)
 		tty_raw(tty, "\033[?1000l");
 
 	tty_raw(tty, tty_term_string(tty->term, TTYC_RMCUP));
+
+	if (tty->xterm_version > 270)
+		tty_raw(tty, "\033[61;1\"p");
 }
 
 void
@@ -844,13 +868,28 @@ tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct window_pane	*wp = ctx->wp;
 	struct screen		*s = wp->screen;
+	char			 tmp[64];
 
 	if (ctx->ocy != ctx->orlower)
 		return;
 
 	if (ctx->xoff != 0 || screen_size_x(s) < tty->sx ||
 	    !tty_term_has(tty->term, TTYC_CSR)) {
-		tty_redraw_region(tty, ctx);
+		if (tty_large_region(tty, ctx))
+			wp->flags |= PANE_REDRAW;
+		else if (tty->xterm_version > 270) {
+			snprintf(tmp, sizeof tmp,
+			    "\033[%u;%u;%u;%u;1;%u;%u;1$v",
+			    ctx->yoff + ctx->orupper + 2,
+			    ctx->xoff + 1,
+			    ctx->yoff + ctx->orlower + 1,
+			    ctx->xoff + screen_size_x(s),
+			    ctx->yoff + ctx->orupper + 1,
+			    ctx->xoff + 1);
+			tty_puts(tty, tmp);
+			tty_cmd_clearline(tty, ctx);
+		} else
+			tty_redraw_region(tty, ctx);
 		return;
 	}