From 8be8016a7653a202666fb1cb46a91d881cbd3ac2 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Sun, 12 Jul 2009 17:03:11 +0000
Subject: [PATCH] When the terminal size is reduced horizontally, don't
 truncate lines to the new width, so that if the same lines are later
 increased in size the content reappears.

---
 screen.c | 45 ++++++++++-----------------------------------
 1 file changed, 10 insertions(+), 35 deletions(-)

diff --git a/screen.c b/screen.c
index 40274cdd..a5d7161d 100644
--- a/screen.c
+++ b/screen.c
@@ -1,4 +1,4 @@
-/* $Id: screen.c,v 1.90 2009-07-08 18:03:03 nicm Exp $ */
+/* $Id: screen.c,v 1.91 2009-07-12 17:03:11 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -121,44 +121,19 @@ void
 screen_resize_x(struct screen *s, u_int sx)
 {
 	struct grid		*gd = s->grid;
-	const struct grid_cell	*gc;
-	const struct grid_utf8	*gu;
-	u_int			 xx, yy;
 
 	if (sx == 0)
 		fatalx("zero size");
 
-	/* If getting larger, not much to do. */
-	if (sx > screen_size_x(s)) {
-		gd->sx = sx;
-		return;
-	}
-
-	/* If getting smaller, nuke any data in lines over the new size. */
-	for (yy = gd->hsize; yy < gd->hsize + screen_size_y(s); yy++) {
-		/*
-		 * If the character after the last is wide or padding, remove
-		 * it and any leading padding.
-		 */
-		gc = &grid_default_cell;
-		for (xx = sx; xx > 0; xx--) {
-			gc = grid_peek_cell(gd, xx - 1, yy);
-			if (!(gc->flags & GRID_FLAG_PADDING))
-				break;
-			grid_set_cell(gd, xx - 1, yy, &grid_default_cell);
-		}
-		if (xx > 0 && xx != sx && gc->flags & GRID_FLAG_UTF8) {
-			gu = grid_peek_utf8(gd, xx - 1, yy);
-			if (gu->width > 1) {
-				grid_set_cell(
-				    gd, xx - 1, yy, &grid_default_cell);
-			}
-		}
-
-		/* Reduce the line size. */
-		grid_reduce_line(gd, yy, sx);
-	}
-
+	/*
+	 * Treat resizing horizontally simply: just ensure the cursor is
+	 * on-screen and change the size. Don't bother to truncate any lines -
+	 * then the data should be accessible if the size is then incrased.
+	 *
+	 * The only potential wrinkle is if UTF-8 double-width characters are
+	 * left in the last column, but UTF-8 terminals should deal with this
+	 * sanely.
+	 */
 	if (s->cx >= sx)
 		s->cx = sx - 1;
 	gd->sx = sx;