From a572533c891713deca3898e6999db63ef6e247df Mon Sep 17 00:00:00 2001
From: Tiago Cunha <tcunha@gmx.com>
Date: Fri, 23 Oct 2009 17:23:52 +0000
Subject: [PATCH] Sync OpenBSD patchset 427:

Don't redraw the scroll region on linefeed/reverse index unless it is necessary
(the cursor is at the bottom/top). Should fix slow cursor movement when using
vi in a pane spotted by pirofti@.
---
 tty.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/tty.c b/tty.c
index c31706f7..028fab69 100644
--- a/tty.c
+++ b/tty.c
@@ -1,4 +1,4 @@
-/* $Id: tty.c,v 1.159 2009-10-23 17:22:39 tcunha Exp $ */
+/* $Id: tty.c,v 1.160 2009-10-23 17:23:52 tcunha Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -689,20 +689,21 @@ tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
   	struct window_pane	*wp = ctx->wp;
 	struct screen		*s = wp->screen;
 
+	if (ctx->ocy != ctx->orupper)
+		return;
+
  	if (wp->xoff != 0 || screen_size_x(s) < tty->sx ||
 	    !tty_term_has(tty->term, TTYC_CSR)) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	if (ctx->ocy == ctx->orupper) {
-		tty_reset(tty);
-
-		tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
-		tty_cursor_pane(tty, ctx, ctx->ocx, ctx->orupper);
-
-		tty_putcode(tty, TTYC_RI);
-	}
+	tty_reset(tty);
+	
+	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
+	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->orupper);
+	
+	tty_putcode(tty, TTYC_RI);
 }
 
 void
@@ -711,6 +712,9 @@ tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
   	struct window_pane	*wp = ctx->wp;
 	struct screen		*s = wp->screen;
 
+	if (ctx->ocy != ctx->orlower)
+		return;
+
  	if (wp->xoff != 0 || screen_size_x(s) < tty->sx ||
 	    !tty_term_has(tty->term, TTYC_CSR)) {
 		tty_redraw_region(tty, ctx);
@@ -725,14 +729,12 @@ tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
 	if (ctx->num && !(tty->term->flags & TERM_EARLYWRAP))
 		return;
 
-	if (ctx->ocy == ctx->orlower) {
-		tty_reset(tty);
-
-		tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
-		tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
-
-		tty_putc(tty, '\n');
-	}
+	tty_reset(tty);
+	
+	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
+	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
+	
+	tty_putc(tty, '\n');
 }
 
 void