Add support for BCE (background colour erase). This makes various escape

sequences (notable EL and ED but also IL, DL, ICH, DCH) create blank
cells using the current background colour rather than the default
colour.

On modern systems BCE doesn't really have many benefits, but most other
terminals now support it, some (lazy) applications rely on it, and it is
not hard to include now that we have pane background colours anyway.

Mostly written by Sean Haugh.

12 files changed, 290 insertions, 210 deletions

diff --git a/usr.bin/tmux/grid-view.c b/usr.bin/tmux/grid-view.c
index 95041712ff7..df9e7ced101 100644
--- a/usr.bin/tmux/grid-view.c
+++ b/usr.bin/tmux/grid-view.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: grid-view.c,v 1.25 2016/09/02 20:57:20 nicm Exp $ */
+/* $OpenBSD: grid-view.c,v 1.26 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -47,7 +47,7 @@ grid_view_set_cell(struct grid *gd, u_int px, u_int py,
 
 /* Clear into history. */
 void
-grid_view_clear_history(struct grid *gd)
+grid_view_clear_history(struct grid *gd, u_int bg)
 {
 	struct grid_line	*gl;
 	u_int			 yy, last;
@@ -56,28 +56,33 @@ grid_view_clear_history(struct grid *gd)
 	last = 0;
 	for (yy = 0; yy < gd->sy; yy++) {
 		gl = &gd->linedata[grid_view_y(gd, yy)];
-		if (gl->cellsize != 0)
+		if (gl->cellused != 0)
 			last = yy + 1;
 	}
-	if (last == 0)
+	if (last == 0) {
+		grid_view_clear(gd, 0, 0, gd->sx, gd->sy, bg);
 		return;
+	}
 
 	/* Scroll the lines into the history. */
 	for (yy = 0; yy < last; yy++) {
-		grid_collect_history(gd);
-		grid_scroll_history(gd);
+		grid_collect_history(gd, bg);
+		grid_scroll_history(gd, bg);
 	}
+	if (last < gd->sy)
+		grid_view_clear(gd, 0, 0, gd->sx, gd->sy - last, bg);
 	gd->hscrolled = 0;
 }
 
 /* Clear area. */
 void
-grid_view_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny)
+grid_view_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny,
+    u_int bg)
 {
 	px = grid_view_x(gd, px);
 	py = grid_view_y(gd, py);
 
-	grid_clear(gd, px, py, nx, ny);
+	grid_clear(gd, px, py, nx, ny, bg);
 }
 
 /* Scroll region up. */
@@ -85,9 +90,9 @@ void
 grid_view_scroll_region_up(struct grid *gd, u_int rupper, u_int rlower)
 {
 	if (gd->flags & GRID_HISTORY) {
-		grid_collect_history(gd);
+		grid_collect_history(gd, 8);
 		if (rupper == 0 && rlower == gd->sy - 1)
-			grid_scroll_history(gd);
+			grid_scroll_history(gd, 8);
 		else {
 			rupper = grid_view_y(gd, rupper);
 			rlower = grid_view_y(gd, rlower);
@@ -96,7 +101,7 @@ grid_view_scroll_region_up(struct grid *gd, u_int rupper, u_int rlower)
 	} else {
 		rupper = grid_view_y(gd, rupper);
 		rlower = grid_view_y(gd, rlower);
-		grid_move_lines(gd, rupper, rupper + 1, rlower - rupper);
+		grid_move_lines(gd, rupper, rupper + 1, rlower - rupper, 8);
 	}
 }
 
@@ -107,12 +112,12 @@ grid_view_scroll_region_down(struct grid *gd, u_int rupper, u_int rlower)
 	rupper = grid_view_y(gd, rupper);
 	rlower = grid_view_y(gd, rlower);
 
-	grid_move_lines(gd, rupper + 1, rupper, rlower - rupper);
+	grid_move_lines(gd, rupper + 1, rupper, rlower - rupper, 8);
 }
 
 /* Insert lines. */
 void
-grid_view_insert_lines(struct grid *gd, u_int py, u_int ny)
+grid_view_insert_lines(struct grid *gd, u_int py, u_int ny, u_int bg)
 {
 	u_int	sy;
 
@@ -120,13 +125,13 @@ grid_view_insert_lines(struct grid *gd, u_int py, u_int ny)
 
 	sy = grid_view_y(gd, gd->sy);
 
-	grid_move_lines(gd, py + ny, py, sy - py - ny);
+	grid_move_lines(gd, py + ny, py, sy - py - ny, bg);
 }
 
 /* Insert lines in region. */
 void
 grid_view_insert_lines_region(struct grid *gd, u_int rlower, u_int py,
-    u_int ny)
+    u_int ny, u_int bg)
 {
 	u_int	ny2;
 
@@ -135,13 +140,13 @@ grid_view_insert_lines_region(struct grid *gd, u_int rlower, u_int py,
 	py = grid_view_y(gd, py);
 
 	ny2 = rlower + 1 - py - ny;
-	grid_move_lines(gd, rlower + 1 - ny2, py, ny2);
-	grid_clear(gd, 0, py + ny2, gd->sx, ny - ny2);
+	grid_move_lines(gd, rlower + 1 - ny2, py, ny2, bg);
+	grid_clear(gd, 0, py + ny2, gd->sx, ny - ny2, bg);
 }
 
 /* Delete lines. */
 void
-grid_view_delete_lines(struct grid *gd, u_int py, u_int ny)
+grid_view_delete_lines(struct grid *gd, u_int py, u_int ny, u_int bg)
 {
 	u_int	sy;
 
@@ -149,14 +154,14 @@ grid_view_delete_lines(struct grid *gd, u_int py, u_int ny)
 
 	sy = grid_view_y(gd, gd->sy);
 
-	grid_move_lines(gd, py, py + ny, sy - py - ny);
-	grid_clear(gd, 0, sy - ny, gd->sx, py + ny - (sy - ny));
+	grid_move_lines(gd, py, py + ny, sy - py - ny, bg);
+	grid_clear(gd, 0, sy - ny, gd->sx, py + ny - (sy - ny), bg);
 }
 
 /* Delete lines inside scroll region. */
 void
 grid_view_delete_lines_region(struct grid *gd, u_int rlower, u_int py,
-    u_int ny)
+    u_int ny, u_int bg)
 {
 	u_int	ny2;
 
@@ -165,13 +170,13 @@ grid_view_delete_lines_region(struct grid *gd, u_int rlower, u_int py,
 	py = grid_view_y(gd, py);
 
 	ny2 = rlower + 1 - py - ny;
-	grid_move_lines(gd, py, py + ny, ny2);
-	grid_clear(gd, 0, py + ny2, gd->sx, ny - ny2);
+	grid_move_lines(gd, py, py + ny, ny2, bg);
+	grid_clear(gd, 0, py + ny2, gd->sx, ny - ny2, bg);
 }
 
 /* Insert characters. */
 void
-grid_view_insert_cells(struct grid *gd, u_int px, u_int py, u_int nx)
+grid_view_insert_cells(struct grid *gd, u_int px, u_int py, u_int nx, u_int bg)
 {
 	u_int	sx;
 
@@ -181,14 +186,14 @@ grid_view_insert_cells(struct grid *gd, u_int px, u_int py, u_int nx)
 	sx = grid_view_x(gd, gd->sx);
 
 	if (px == sx - 1)
-		grid_clear(gd, px, py, 1, 1);
+		grid_clear(gd, px, py, 1, 1, bg);
 	else
-		grid_move_cells(gd, px + nx, px, py, sx - px - nx);
+		grid_move_cells(gd, px + nx, px, py, sx - px - nx, bg);
 }
 
 /* Delete characters. */
 void
-grid_view_delete_cells(struct grid *gd, u_int px, u_int py, u_int nx)
+grid_view_delete_cells(struct grid *gd, u_int px, u_int py, u_int nx, u_int bg)
 {
 	u_int	sx;
 
@@ -197,8 +202,8 @@ grid_view_delete_cells(struct grid *gd, u_int px, u_int py, u_int nx)
 
 	sx = grid_view_x(gd, gd->sx);
 
-	grid_move_cells(gd, px, px + nx, py, sx - px - nx);
-	grid_clear(gd, sx - nx, py, px + nx - (sx - nx), 1);
+	grid_move_cells(gd, px, px + nx, py, sx - px - nx, bg);
+	grid_clear(gd, sx - nx, py, px + nx - (sx - nx), 1, bg);
 }
 
 /* Convert cells into a string. */
diff --git a/usr.bin/tmux/grid.c b/usr.bin/tmux/grid.c
index 4d56d85b6c3..0e1fcdf1dd3 100644
--- a/usr.bin/tmux/grid.c
+++ b/usr.bin/tmux/grid.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: grid.c,v 1.57 2016/10/11 13:21:59 nicm Exp $ */
+/* $OpenBSD: grid.c,v 1.58 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -43,7 +43,8 @@ const struct grid_cell_entry grid_default_entry = {
 	0, { .data = { 0, 8, 8, ' ' } }
 };
 
-static void	grid_expand_line(struct grid *, u_int, u_int);
+static void	grid_expand_line(struct grid *, u_int, u_int, u_int);
+static void	grid_empty_line(struct grid *, u_int, u_int);
 
 static void	grid_reflow_copy(struct grid_line *, u_int, struct grid_line *,
 		    u_int, u_int);
@@ -60,9 +61,10 @@ static void	grid_string_cells_code(const struct grid_cell *,
 
 /* Copy default into a cell. */
 static void
-grid_clear_cell(struct grid *gd, u_int px, u_int py)
+grid_clear_cell(struct grid *gd, u_int px, u_int py, u_int bg)
 {
 	gd->linedata[py].celldata[px] = grid_default_entry;
+	gd->linedata[py].celldata[px].data.bg = bg;
 }
 
 /* Check grid y position. */
@@ -162,7 +164,7 @@ grid_compare(struct grid *ga, struct grid *gb)
  * and shift up.
  */
 void
-grid_collect_history(struct grid *gd)
+grid_collect_history(struct grid *gd, u_int bg)
 {
 	u_int	yy;
 
@@ -173,7 +175,7 @@ grid_collect_history(struct grid *gd)
 	if (yy < 1)
 		yy = 1;
 
-	grid_move_lines(gd, 0, yy, gd->hsize + gd->sy - yy);
+	grid_move_lines(gd, 0, yy, gd->hsize + gd->sy - yy, bg);
 	gd->hsize -= yy;
 	if (gd->hscrolled > gd->hsize)
 		gd->hscrolled = gd->hsize;
@@ -184,14 +186,14 @@ grid_collect_history(struct grid *gd)
  * allocate a new line at the bottom and move the history size indicator.
  */
 void
-grid_scroll_history(struct grid *gd)
+grid_scroll_history(struct grid *gd, u_int bg)
 {
 	u_int	yy;
 
 	yy = gd->hsize + gd->sy;
 	gd->linedata = xreallocarray(gd->linedata, yy + 1,
 	    sizeof *gd->linedata);
-	memset(&gd->linedata[yy], 0, sizeof gd->linedata[yy]);
+	grid_empty_line(gd, yy, bg);
 
 	gd->hscrolled++;
 	gd->hsize++;
@@ -201,8 +203,8 @@ grid_scroll_history(struct grid *gd)
 void
 grid_clear_history(struct grid *gd)
 {
-	grid_clear_lines(gd, 0, gd->hsize);
-	grid_move_lines(gd, 0, gd->hsize, gd->sy);
+	grid_clear_lines(gd, 0, gd->hsize, 8);
+	grid_move_lines(gd, 0, gd->hsize, gd->sy, 8);
 
 	gd->hscrolled = 0;
 	gd->hsize = 0;
@@ -247,7 +249,7 @@ grid_scroll_history_region(struct grid *gd, u_int upper, u_int lower)
 
 /* Expand line to fit to cell. */
 static void
-grid_expand_line(struct grid *gd, u_int py, u_int sx)
+grid_expand_line(struct grid *gd, u_int py, u_int sx, u_int bg)
 {
 	struct grid_line	*gl;
 	u_int			 xx;
@@ -258,10 +260,19 @@ grid_expand_line(struct grid *gd, u_int py, u_int sx)
 
 	gl->celldata = xreallocarray(gl->celldata, sx, sizeof *gl->celldata);
 	for (xx = gl->cellsize; xx < sx; xx++)
-		grid_clear_cell(gd, xx, py);
+		grid_clear_cell(gd, xx, py, bg);
 	gl->cellsize = sx;
 }
 
+/* Empty a line and set background colour if needed. */
+static void
+grid_empty_line(struct grid *gd, u_int py, u_int bg)
+{
+	memset(&gd->linedata[py], 0, sizeof gd->linedata[py]);
+	if (bg != 8)
+		grid_expand_line(gd, py, gd->sx, bg);
+}
+
 /* Peek at grid line. */
 const struct grid_line *
 grid_peek_line(struct grid *gd, u_int py)
@@ -317,11 +328,14 @@ grid_set_cell(struct grid *gd, u_int px, u_int py, const struct grid_cell *gc)
 	if (grid_check_y(gd, py) != 0)
 		return;
 
-	grid_expand_line(gd, py, px + 1);
+	grid_expand_line(gd, py, px + 1, 8);
 
 	gl = &gd->linedata[py];
 	gce = &gl->celldata[px];
 
+	if (px + 1 > gl->cellused)
+		gl->cellused = px + 1;
+
 	extended = (gce->flags & GRID_FLAG_EXTENDED);
 	if (!extended && (gc->data.size != 1 || gc->data.width != 1))
 		extended = 1;
@@ -358,7 +372,7 @@ grid_set_cell(struct grid *gd, u_int px, u_int py, const struct grid_cell *gc)
 
 /* Clear area. */
 void
-grid_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny)
+grid_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny, u_int bg)
 {
 	u_int	xx, yy;
 
@@ -366,7 +380,7 @@ grid_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny)
 		return;
 
 	if (px == 0 && nx == gd->sx) {
-		grid_clear_lines(gd, py, ny);
+		grid_clear_lines(gd, py, ny, bg);
 		return;
 	}
 
@@ -376,23 +390,23 @@ grid_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny)
 		return;
 
 	for (yy = py; yy < py + ny; yy++) {
-		if (px >= gd->linedata[yy].cellsize)
+		if (px + nx >= gd->sx && px < gd->linedata[yy].cellused)
+			gd->linedata[yy].cellused = px;
+		if (px > gd->linedata[yy].cellsize && bg == 8)
 			continue;
-		if (px + nx >= gd->linedata[yy].cellsize) {
+		if (px + nx >= gd->linedata[yy].cellsize && bg == 8) {
 			gd->linedata[yy].cellsize = px;
 			continue;
 		}
-		for (xx = px; xx < px + nx; xx++) {
-			if (xx >= gd->linedata[yy].cellsize)
-				break;
-			grid_clear_cell(gd, xx, yy);
-		}
+		grid_expand_line(gd, yy, px + nx, bg);
+		for (xx = px; xx < px + nx; xx++)
+			grid_clear_cell(gd, xx, yy, bg);
 	}
 }
 
 /* Clear lines. This just frees and truncates the lines. */
 void
-grid_clear_lines(struct grid *gd, u_int py, u_int ny)
+grid_clear_lines(struct grid *gd, u_int py, u_int ny, u_int bg)
 {
 	struct grid_line	*gl;
 	u_int			 yy;
@@ -409,13 +423,13 @@ grid_clear_lines(struct grid *gd, u_int py, u_int ny)
 		gl = &gd->linedata[yy];
 		free(gl->celldata);
 		free(gl->extddata);
-		memset(gl, 0, sizeof *gl);
+		grid_empty_line(gd, yy, bg);
 	}
 }
 
 /* Move a group of lines. */
 void
-grid_move_lines(struct grid *gd, u_int dy, u_int py, u_int ny)
+grid_move_lines(struct grid *gd, u_int dy, u_int py, u_int ny, u_int bg)
 {
 	u_int	yy;
 
@@ -435,7 +449,7 @@ grid_move_lines(struct grid *gd, u_int dy, u_int py, u_int ny)
 	for (yy = dy; yy < dy + ny; yy++) {
 		if (yy >= py && yy < py + ny)
 			continue;
-		grid_clear_lines(gd, yy, 1);
+		grid_clear_lines(gd, yy, 1, bg);
 	}
 
 	memmove(&gd->linedata[dy], &gd->linedata[py],
@@ -443,15 +457,15 @@ grid_move_lines(struct grid *gd, u_int dy, u_int py, u_int ny)
 
 	/* Wipe any lines that have been moved (without freeing them). */
 	for (yy = py; yy < py + ny; yy++) {
-		if (yy >= dy && yy < dy + ny)
-			continue;
-		memset(&gd->linedata[yy], 0, sizeof gd->linedata[yy]);
+		if (yy < dy || yy >= dy + ny)
+			grid_empty_line(gd, yy, bg);
 	}
 }
 
 /* Move a group of cells. */
 void
-grid_move_cells(struct grid *gd, u_int dx, u_int px, u_int py, u_int nx)
+grid_move_cells(struct grid *gd, u_int dx, u_int px, u_int py, u_int nx,
+    u_int bg)
 {
 	struct grid_line	*gl;
 	u_int			 xx;
@@ -463,8 +477,8 @@ grid_move_cells(struct grid *gd, u_int dx, u_int px, u_int py, u_int nx)
 		return;
 	gl = &gd->linedata[py];
 
-	grid_expand_line(gd, py, px + nx);
-	grid_expand_line(gd, py, dx + nx);
+	grid_expand_line(gd, py, px + nx, 8);
+	grid_expand_line(gd, py, dx + nx, 8);
 	memmove(&gl->celldata[dx], &gl->celldata[px],
 	    nx * sizeof *gl->celldata);
 
@@ -472,7 +486,7 @@ grid_move_cells(struct grid *gd, u_int dx, u_int px, u_int py, u_int nx)
 	for (xx = px; xx < px + nx; xx++) {
 		if (xx >= dx && xx < dx + nx)
 			continue;
-		grid_clear_cell(gd, xx, py);
+		grid_clear_cell(gd, xx, py, bg);
 	}
 }
 
@@ -748,7 +762,7 @@ grid_duplicate_lines(struct grid *dst, u_int dy, struct grid *src, u_int sy,
 		ny = dst->hsize + dst->sy - dy;
 	if (sy + ny > src->hsize + src->sy)
 		ny = src->hsize + src->sy - sy;
-	grid_clear_lines(dst, dy, ny);
+	grid_clear_lines(dst, dy, ny, 8);
 
 	for (yy = 0; yy < ny; yy++) {
 		srcl = &src->linedata[sy];
@@ -810,28 +824,28 @@ grid_reflow_join(struct grid *dst, u_int *py, struct grid_line *src_gl,
 	u_int			 left, to_copy, ox, nx;
 
 	/* How much is left on the old line? */
-	left = new_x - dst_gl->cellsize;
+	left = new_x - dst_gl->cellused;
 
 	/* Work out how much to append. */
-	to_copy = src_gl->cellsize;
+	to_copy = src_gl->cellused;
 	if (to_copy > left)
 		to_copy = left;
-	ox = dst_gl->cellsize;
+	ox = dst_gl->cellused;
 	nx = ox + to_copy;
 
 	/* Resize the destination line. */
 	dst_gl->celldata = xreallocarray(dst_gl->celldata, nx,
 	    sizeof *dst_gl->celldata);
-	dst_gl->cellsize = nx;
+	dst_gl->cellsize = dst_gl->cellused = nx;
 
 	/* Append as much as possible. */
 	grid_reflow_copy(dst_gl, ox, src_gl, 0, to_copy);
 
 	/* If there is any left in the source, split it. */
-	if (src_gl->cellsize > to_copy) {
+	if (src_gl->cellused > to_copy) {
 		dst_gl->flags |= GRID_LINE_WRAPPED;
 
-		src_gl->cellsize -= to_copy;
+		src_gl->cellused -= to_copy;
 		grid_reflow_split(dst, py, src_gl, new_x, to_copy);
 	}
 }
@@ -845,22 +859,22 @@ grid_reflow_split(struct grid *dst, u_int *py, struct grid_line *src_gl,
 	u_int			 to_copy;
 
 	/* Loop and copy sections of the source line. */
-	while (src_gl->cellsize > 0) {
+	while (src_gl->cellused > 0) {
 		/* Create new line. */
 		if (*py >= dst->hsize + dst->sy)
-			grid_scroll_history(dst);
+			grid_scroll_history(dst, 8);
 		dst_gl = &dst->linedata[*py];
 		(*py)++;
 
 		/* How much should we copy? */
 		to_copy = new_x;
-		if (to_copy > src_gl->cellsize)
-			to_copy = src_gl->cellsize;
+		if (to_copy > src_gl->cellused)
+			to_copy = src_gl->cellused;
 
 		/* Expand destination line. */
 		dst_gl->celldata = xreallocarray(NULL, to_copy,
 		    sizeof *dst_gl->celldata);
-		dst_gl->cellsize = to_copy;
+		dst_gl->cellsize = dst_gl->cellused = to_copy;
 		dst_gl->flags |= GRID_LINE_WRAPPED;
 
 		/* Copy the data. */
@@ -868,7 +882,7 @@ grid_reflow_split(struct grid *dst, u_int *py, struct grid_line *src_gl,
 
 		/* Move offset and reduce old line size. */
 		offset += to_copy;
-		src_gl->cellsize -= to_copy;
+		src_gl->cellused -= to_copy;
 	}
 
 	/* Last line is not wrapped. */
@@ -884,7 +898,7 @@ grid_reflow_move(struct grid *dst, u_int *py, struct grid_line *src_gl)
 
 	/* Create new line. */
 	if (*py >= dst->hsize + dst->sy)
-		grid_scroll_history(dst);
+		grid_scroll_history(dst, 8);
 	dst_gl = &dst->linedata[*py];
 	(*py)++;
 
@@ -916,7 +930,7 @@ grid_reflow(struct grid *dst, struct grid *src, u_int new_x)
 		src_gl = src->linedata + line;
 		if (!previous_wrapped) {
 			/* Wasn't wrapped. If smaller, move to destination. */
-			if (src_gl->cellsize <= new_x)
+			if (src_gl->cellused <= new_x)
 				grid_reflow_move(dst, &py, src_gl);
 			else
 				grid_reflow_split(dst, &py, src_gl, new_x, 0);
diff --git a/usr.bin/tmux/input.c b/usr.bin/tmux/input.c
index 9ab3061386c..8ff96327e74 100644
--- a/usr.bin/tmux/input.c
+++ b/usr.bin/tmux/input.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: input.c,v 1.104 2016/10/03 22:52:11 nicm Exp $ */
+/* $OpenBSD: input.c,v 1.105 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1283,7 +1283,8 @@ input_csi_dispatch(struct input_ctx *ictx)
 		screen_write_clearcharacter(sctx, input_get(ictx, 0, 1, 1));
 		break;
 	case INPUT_CSI_DCH:
-		screen_write_deletecharacter(sctx, input_get(ictx, 0, 1, 1));
+		screen_write_deletecharacter(sctx, input_get(ictx, 0, 1, 1),
+		    ictx->cell.cell.bg);
 		break;
 	case INPUT_CSI_DECSTBM:
 		n = input_get(ictx, 0, 1, 1);
@@ -1291,7 +1292,8 @@ input_csi_dispatch(struct input_ctx *ictx)
 		screen_write_scrollregion(sctx, n - 1, m - 1);
 		break;
 	case INPUT_CSI_DL:
-		screen_write_deleteline(sctx, input_get(ictx, 0, 1, 1));
+		screen_write_deleteline(sctx, input_get(ictx, 0, 1, 1),
+		    ictx->cell.cell.bg);
 		break;
 	case INPUT_CSI_DSR:
 		switch (input_get(ictx, 0, 0, 0)) {
@@ -1309,13 +1311,13 @@ input_csi_dispatch(struct input_ctx *ictx)
 	case INPUT_CSI_ED:
 		switch (input_get(ictx, 0, 0, 0)) {
 		case 0:
-			screen_write_clearendofscreen(sctx);
+			screen_write_clearendofscreen(sctx, ictx->cell.cell.bg);
 			break;
 		case 1:
 			screen_write_clearstartofscreen(sctx);
 			break;
 		case 2:
-			screen_write_clearscreen(sctx);
+			screen_write_clearscreen(sctx, ictx->cell.cell.bg);
 			break;
 		case 3:
 			switch (input_get(ictx, 1, 0, 0)) {
@@ -1336,13 +1338,13 @@ input_csi_dispatch(struct input_ctx *ictx)
 	case INPUT_CSI_EL:
 		switch (input_get(ictx, 0, 0, 0)) {
 		case 0:
-			screen_write_clearendofline(sctx);
+			screen_write_clearendofline(sctx, ictx->cell.cell.bg);
 			break;
 		case 1:
-			screen_write_clearstartofline(sctx);
+			screen_write_clearstartofline(sctx, ictx->cell.cell.bg);
 			break;
 		case 2:
-			screen_write_clearline(sctx);
+			screen_write_clearline(sctx, ictx->cell.cell.bg);
 			break;
 		default:
 			log_debug("%s: unknown '%c'", __func__, ictx->ch);
@@ -1354,10 +1356,12 @@ input_csi_dispatch(struct input_ctx *ictx)
 		screen_write_cursormove(sctx, n - 1, s->cy);
 		break;
 	case INPUT_CSI_ICH:
-		screen_write_insertcharacter(sctx, input_get(ictx, 0, 1, 1));
+		screen_write_insertcharacter(sctx, input_get(ictx, 0, 1, 1),
+		    ictx->cell.cell.bg);
 		break;
 	case INPUT_CSI_IL:
-		screen_write_insertline(sctx, input_get(ictx, 0, 1, 1));
+		screen_write_insertline(sctx, input_get(ictx, 0, 1, 1),
+			ictx->cell.cell.bg);
 		break;
 	case INPUT_CSI_RCP:
 		memcpy(&ictx->cell, &ictx->old_cell, sizeof ictx->cell);
@@ -1445,7 +1449,8 @@ input_csi_dispatch_rm_private(struct input_ctx *ictx)
 			break;
 		case 3:		/* DECCOLM */
 			screen_write_cursormove(&ictx->ctx, 0, 0);
-			screen_write_clearscreen(&ictx->ctx);
+			screen_write_clearscreen(&ictx->ctx,
+			    ictx->cell.cell.bg);
 			break;
 		case 7:		/* DECAWM */
 			screen_write_mode_clear(&ictx->ctx, MODE_WRAP);
@@ -1522,7 +1527,8 @@ input_csi_dispatch_sm_private(struct input_ctx *ictx)
 			break;
 		case 3:		/* DECCOLM */
 			screen_write_cursormove(&ictx->ctx, 0, 0);
-			screen_write_clearscreen(&ictx->ctx);
+			screen_write_clearscreen(&ictx->ctx,
+			    ictx->cell.cell.bg);
 			break;
 		case 7:		/* DECAWM */
 			screen_write_mode_set(&ictx->ctx, MODE_WRAP);
diff --git a/usr.bin/tmux/screen-redraw.c b/usr.bin/tmux/screen-redraw.c
index 27d9effd060..617f636a76c 100644
--- a/usr.bin/tmux/screen-redraw.c
+++ b/usr.bin/tmux/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.40 2016/10/12 17:36:52 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.41 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -295,7 +295,7 @@ screen_redraw_make_pane_status(struct client *c, struct window *w,
 
 	screen_write_start(&ctx, NULL, &wp->status_screen);
 	screen_write_cursormove(&ctx, 0, 0);
-	screen_write_clearline(&ctx);
+	screen_write_clearline(&ctx, 8);
 	screen_write_cnputs(&ctx, outlen, &gc, "%s", out);
 	screen_write_stop(&ctx);
 
diff --git a/usr.bin/tmux/screen-write.c b/usr.bin/tmux/screen-write.c
index dea56fa3e96..81d33ce5c7d 100644
--- a/usr.bin/tmux/screen-write.c
+++ b/usr.bin/tmux/screen-write.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-write.c,v 1.98 2016/10/12 15:43:51 nicm Exp $ */
+/* $OpenBSD: screen-write.c,v 1.99 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -147,7 +147,7 @@ screen_write_reset(struct screen_write_ctx *ctx)
 	s->mode &= ~(MODE_INSERT|MODE_KCURSOR|MODE_KKEYPAD|MODE_FOCUSON);
 	s->mode &= ~(ALL_MOUSE_MODES|MODE_MOUSE_UTF8|MODE_MOUSE_SGR);
 
-	screen_write_clearscreen(ctx);
+	screen_write_clearscreen(ctx, 8);
 	screen_write_cursormove(ctx, 0, 0);
 }
 
@@ -601,7 +601,7 @@ screen_write_alignmenttest(struct screen_write_ctx *ctx)
 
 /* Insert nx characters. */
 void
-screen_write_insertcharacter(struct screen_write_ctx *ctx, u_int nx)
+screen_write_insertcharacter(struct screen_write_ctx *ctx, u_int nx, u_int bg)
 {
 	struct screen	*s = ctx->s;
 	struct tty_ctx	 ttyctx;
@@ -618,15 +618,16 @@ screen_write_insertcharacter(struct screen_write_ctx *ctx, u_int nx)
 	screen_write_initctx(ctx, &ttyctx);
 
 	if (s->cx <= screen_size_x(s) - 1)
-		grid_view_insert_cells(s->grid, s->cx, s->cy, nx);
+		grid_view_insert_cells(s->grid, s->cx, s->cy, nx, bg);
 
 	ttyctx.num = nx;
+	ttyctx.bg = bg;
 	tty_write(tty_cmd_insertcharacter, &ttyctx);
 }
 
 /* Delete nx characters. */
 void
-screen_write_deletecharacter(struct screen_write_ctx *ctx, u_int nx)
+screen_write_deletecharacter(struct screen_write_ctx *ctx, u_int nx, u_int bg)
 {
 	struct screen	*s = ctx->s;
 	struct tty_ctx	 ttyctx;
@@ -643,9 +644,10 @@ screen_write_deletecharacter(struct screen_write_ctx *ctx, u_int nx)
 	screen_write_initctx(ctx, &ttyctx);
 
 	if (s->cx <= screen_size_x(s) - 1)
-		grid_view_delete_cells(s->grid, s->cx, s->cy, nx);
+		grid_view_delete_cells(s->grid, s->cx, s->cy, nx, bg);
 
 	ttyctx.num = nx;
+	ttyctx.bg = bg;
 	tty_write(tty_cmd_deletecharacter, &ttyctx);
 }
 
@@ -668,7 +670,7 @@ screen_write_clearcharacter(struct screen_write_ctx *ctx, u_int nx)
 
 	if (s->cx <= screen_size_x(s) - 1) {
 		screen_dirty_clear(s, s->cx, s->cy, s->cx + nx - 1, s->cy);
-		grid_view_clear(s->grid, s->cx, s->cy, nx, 1);
+		grid_view_clear(s->grid, s->cx, s->cy, nx, 1, 8);
 	} else
 		return;
 
@@ -678,7 +680,7 @@ screen_write_clearcharacter(struct screen_write_ctx *ctx, u_int nx)
 
 /* Insert ny lines. */
 void
-screen_write_insertline(struct screen_write_ctx *ctx, u_int ny)
+screen_write_insertline(struct screen_write_ctx *ctx, u_int ny, u_int bg)
 {
 	struct screen	*s = ctx->s;
 	struct tty_ctx	 ttyctx;
@@ -695,9 +697,10 @@ screen_write_insertline(struct screen_write_ctx *ctx, u_int ny)
 		screen_write_flush(ctx);
 		screen_write_initctx(ctx, &ttyctx);
 
-		grid_view_insert_lines(s->grid, s->cy, ny);
+		grid_view_insert_lines(s->grid, s->cy, ny, bg);
 
 		ttyctx.num = ny;
+		ttyctx.bg = bg;
 		tty_write(tty_cmd_insertline, &ttyctx);
 		return;
 	}
@@ -711,17 +714,20 @@ screen_write_insertline(struct screen_write_ctx *ctx, u_int ny)
 	screen_write_initctx(ctx, &ttyctx);
 
 	if (s->cy < s->rupper || s->cy > s->rlower)
-		grid_view_insert_lines(s->grid, s->cy, ny);
-	else
-		grid_view_insert_lines_region(s->grid, s->rlower, s->cy, ny);
+		grid_view_insert_lines(s->grid, s->cy, ny, bg);
+	else {
+		grid_view_insert_lines_region(s->grid, s->rlower, s->cy, ny,
+		    bg);
+	}
 
 	ttyctx.num = ny;
+	ttyctx.bg = bg;
 	tty_write(tty_cmd_insertline, &ttyctx);
 }
 
 /* Delete ny lines. */
 void
-screen_write_deleteline(struct screen_write_ctx *ctx, u_int ny)
+screen_write_deleteline(struct screen_write_ctx *ctx, u_int ny, u_int bg)
 {
 	struct screen	*s = ctx->s;
 	struct tty_ctx	 ttyctx;
@@ -738,9 +744,10 @@ screen_write_deleteline(struct screen_write_ctx *ctx, u_int ny)
 		screen_write_flush(ctx);
 		screen_write_initctx(ctx, &ttyctx);
 
-		grid_view_delete_lines(s->grid, s->cy, ny);
+		grid_view_delete_lines(s->grid, s->cy, ny, bg);
 
 		ttyctx.num = ny;
+		ttyctx.bg = bg;
 		tty_write(tty_cmd_deleteline, &ttyctx);
 		return;
 	}
@@ -754,17 +761,20 @@ screen_write_deleteline(struct screen_write_ctx *ctx, u_int ny)
 	screen_write_initctx(ctx, &ttyctx);
 
 	if (s->cy < s->rupper || s->cy > s->rlower)
-		grid_view_delete_lines(s->grid, s->cy, ny);
-	else
-		grid_view_delete_lines_region(s->grid, s->rlower, s->cy, ny);
+		grid_view_delete_lines(s->grid, s->cy, ny, bg);
+	else {
+		grid_view_delete_lines_region(s->grid, s->rlower, s->cy, ny,
+		    bg);
+	}
 
 	ttyctx.num = ny;
+	ttyctx.bg = bg;
 	tty_write(tty_cmd_deleteline, &ttyctx);
 }
 
 /* Clear line at cursor. */
 void
-screen_write_clearline(struct screen_write_ctx *ctx)
+screen_write_clearline(struct screen_write_ctx *ctx, u_int bg)
 {
 	struct screen		*s = ctx->s;
 	struct grid_line	*gl;
@@ -772,20 +782,21 @@ screen_write_clearline(struct screen_write_ctx *ctx)
 	u_int			 sx = screen_size_x(s);
 
 	screen_write_initctx(ctx, &ttyctx);
+	ttyctx.bg = bg;
 
 	gl = &s->grid->linedata[s->grid->hsize + s->cy];
-	if (gl->cellsize != 0) {
-		screen_dirty_clear(s, 0, s->cy, sx - 1, s->cy);
-		grid_view_clear(s->grid, 0, s->cy, sx, 1);
-	} else
+	if (gl->cellsize == 0 && bg == 8)
 		return;
 
+	screen_dirty_clear(s, 0, s->cy, sx - 1, s->cy);
+	grid_view_clear(s->grid, 0, s->cy, sx, 1, bg);
+
 	tty_write(tty_cmd_clearline, &ttyctx);
 }
 
 /* Clear to end of line from cursor. */
 void
-screen_write_clearendofline(struct screen_write_ctx *ctx)
+screen_write_clearendofline(struct screen_write_ctx *ctx, u_int bg)
 {
 	struct screen		*s = ctx->s;
 	struct grid_line	*gl;
@@ -793,33 +804,35 @@ screen_write_clearendofline(struct screen_write_ctx *ctx)
 	u_int			 sx = screen_size_x(s);
 
 	screen_write_initctx(ctx, &ttyctx);
+	ttyctx.bg = bg;
 
 	gl = &s->grid->linedata[s->grid->hsize + s->cy];
-	if (s->cx <= sx - 1 && s->cx < gl->cellsize) {
-		screen_dirty_clear(s, s->cx, s->cy, sx - 1, s->cy);
-		grid_view_clear(s->grid, s->cx, s->cy, sx - s->cx, 1);
-	} else
+	if (s->cx > sx - 1 || (s->cx >= gl->cellsize && bg == 8))
 		return;
 
+	screen_dirty_clear(s, s->cx, s->cy, sx - 1, s->cy);
+	grid_view_clear(s->grid, s->cx, s->cy, sx - s->cx, 1, bg);
+
 	tty_write(tty_cmd_clearendofline, &ttyctx);
 }
 
 /* Clear to start of line from cursor. */
 void
-screen_write_clearstartofline(struct screen_write_ctx *ctx)
+screen_write_clearstartofline(struct screen_write_ctx *ctx, u_int bg)
 {
 	struct screen	*s = ctx->s;
 	struct tty_ctx	 ttyctx;
 	u_int		 sx = screen_size_x(s);
 
 	screen_write_initctx(ctx, &ttyctx);
+	ttyctx.bg = bg;
 
 	if (s->cx > sx - 1) {
 		screen_dirty_clear(s, 0, s->cy, sx - 1, s->cy);
-		grid_view_clear(s->grid, 0, s->cy, sx, 1);
+		grid_view_clear(s->grid, 0, s->cy, sx, 1, bg);
 	} else {
 		screen_dirty_clear(s, 0, s->cy, s->cx, s->cy);
-		grid_view_clear(s->grid, 0, s->cy, s->cx + 1, 1);
+		grid_view_clear(s->grid, 0, s->cy, s->cx + 1, 1, bg);
 	}
 
 	tty_write(tty_cmd_clearstartofline, &ttyctx);
@@ -919,25 +932,28 @@ screen_write_carriagereturn(struct screen_write_ctx *ctx)
 
 /* Clear to end of screen from cursor. */
 void
-screen_write_clearendofscreen(struct screen_write_ctx *ctx)
+screen_write_clearendofscreen(struct screen_write_ctx *ctx, u_int bg)
 {
 	struct screen	*s = ctx->s;
 	struct tty_ctx	 ttyctx;
 	u_int		 sx = screen_size_x(s), sy = screen_size_y(s);
 
 	screen_write_initctx(ctx, &ttyctx);
+	ttyctx.bg = bg;
 
 	/* Scroll into history if it is enabled and clearing entire screen. */
-	if (s->cy == 0 && s->grid->flags & GRID_HISTORY) {
+	if (s->cx == 0 && s->cy == 0 && s->grid->flags & GRID_HISTORY) {
 		screen_dirty_clear(s, 0, 0, sx - 1, sy  - 1);
-		grid_view_clear_history(s->grid);
+		grid_view_clear_history(s->grid, bg);
 	} else {
 		if (s->cx <= sx - 1) {
 			screen_dirty_clear(s, s->cx, s->cy, sx - 1, s->cy);
-			grid_view_clear(s->grid, s->cx, s->cy, sx - s->cx, 1);
+			grid_view_clear(s->grid, s->cx, s->cy, sx - s->cx, 1,
+			    bg);
 		}
 		screen_dirty_clear(s, 0, s->cy + 1, sx - 1, sy - 1);
-		grid_view_clear(s->grid, 0, s->cy + 1, sx, sy - (s->cy + 1));
+		grid_view_clear(s->grid, 0, s->cy + 1, sx, sy - (s->cy + 1),
+		    bg);
 	}
 
 	tty_write(tty_cmd_clearendofscreen, &ttyctx);
@@ -955,14 +971,14 @@ screen_write_clearstartofscreen(struct screen_write_ctx *ctx)
 
 	if (s->cy > 0) {
 		screen_dirty_clear(s, 0, 0, sx - 1, s->cy);
-		grid_view_clear(s->grid, 0, 0, sx, s->cy);
+		grid_view_clear(s->grid, 0, 0, sx, s->cy, 8);
 	}
 	if (s->cx > sx - 1) {
 		screen_dirty_clear(s, 0, s->cy, sx - 1, s->cy);
-		grid_view_clear(s->grid, 0, s->cy, sx, 1);
+		grid_view_clear(s->grid, 0, s->cy, sx, 1, 8);
 	} else {
 		screen_dirty_clear(s, 0, s->cy, s->cx, s->cy);
-		grid_view_clear(s->grid, 0, s->cy, s->cx + 1, 1);
+		grid_view_clear(s->grid, 0, s->cy, s->cx + 1, 1, 8);
 	}
 
 	tty_write(tty_cmd_clearstartofscreen, &ttyctx);
@@ -970,21 +986,22 @@ screen_write_clearstartofscreen(struct screen_write_ctx *ctx)
 
 /* Clear entire screen. */
 void
-screen_write_clearscreen(struct screen_write_ctx *ctx)
+screen_write_clearscreen(struct screen_write_ctx *ctx, u_int bg)
 {
 	struct screen	*s = ctx->s;
 	struct tty_ctx	 ttyctx;
 	u_int		 sx = screen_size_x(s), sy = screen_size_y(s);
 
 	screen_write_initctx(ctx, &ttyctx);
+	ttyctx.bg = bg;
 
 	screen_dirty_clear(s, 0, 0, sx - 1, sy  - 1);
 
 	/* Scroll into history if it is enabled. */
 	if (s->grid->flags & GRID_HISTORY)
-		grid_view_clear_history(s->grid);
+		grid_view_clear_history(s->grid, bg);
 	else
-		grid_view_clear(s->grid, 0, 0, sx, sy);
+		grid_view_clear(s->grid, 0, 0, sx, sy, bg);
 
 	tty_write(tty_cmd_clearscreen, &ttyctx);
 }
@@ -996,7 +1013,7 @@ screen_write_clearhistory(struct screen_write_ctx *ctx)
 	struct screen	*s = ctx->s;
 	struct grid	*gd = s->grid;
 
-	grid_move_lines(gd, 0, gd->hsize, gd->sy);
+	grid_move_lines(gd, 0, gd->hsize, gd->sy, 8);
 	gd->hscrolled = gd->hsize = 0;
 }
 
@@ -1049,7 +1066,7 @@ screen_write_cell(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 		if (s->cx <= sx - width) {
 			screen_write_flush(ctx);
 			xx = sx - s->cx - width;
-			grid_view_insert_cells(s->grid, s->cx, s->cy, xx);
+			grid_view_insert_cells(s->grid, s->cx, s->cy, xx, 8);
 		}
 		insert = 1;
 	} else
diff --git a/usr.bin/tmux/screen.c b/usr.bin/tmux/screen.c
index 7fd8f71f0be..931bfebb248 100644
--- a/usr.bin/tmux/screen.c
+++ b/usr.bin/tmux/screen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen.c,v 1.43 2016/10/12 13:24:07 nicm Exp $ */
+/* $OpenBSD: screen.c,v 1.44 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -60,7 +60,7 @@ screen_reinit(struct screen *s)
 
 	screen_reset_tabs(s);
 
-	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy);
+	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy, 8);
 
 	screen_clear_selection(s);
 }
@@ -193,7 +193,8 @@ screen_resize_y(struct screen *s, u_int sy)
 		if (available > 0) {
 			if (available > needed)
 				available = needed;
-			grid_view_delete_lines(gd, oldy - available, available);
+			grid_view_delete_lines(gd, oldy - available, available,
+			    8);
 		}
 		needed -= available;
 
@@ -209,7 +210,7 @@ screen_resize_y(struct screen *s, u_int sy)
 		} else if (needed > 0 && available > 0) {
 			if (available > needed)
 				available = needed;
-			grid_view_delete_lines(gd, 0, available);
+			grid_view_delete_lines(gd, 0, available, 8);
 		}
 		s->cy -= needed;
 	}
diff --git a/usr.bin/tmux/tmux.h b/usr.bin/tmux/tmux.h
index f64ba7beff7..f3b2d3878c4 100644
--- a/usr.bin/tmux/tmux.h
+++ b/usr.bin/tmux/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.660 2016/10/13 10:01:49 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.661 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -602,6 +602,7 @@ struct grid_cell_entry {
 
 /* Grid line. */
 struct grid_line {
+	u_int			 cellused;
 	u_int			 cellsize;
 	struct grid_cell_entry	*celldata;
 
@@ -710,7 +711,7 @@ struct screen {
 	char			*ccolour;	/* cursor colour string */
 
 	u_int			 rupper;	/* scroll region top */
-	u_int		 	 rlower;	/* scroll region bottom */
+	u_int			 rlower;	/* scroll region bottom */
 
 	int			 mode;
 
@@ -1144,6 +1145,9 @@ struct tty_ctx {
 	u_int		 xoff;
 	u_int		 yoff;
 
+	/* The background colour used for clearing (erasing). */
+	u_int		 bg;
+
 	/* Saved last cell on line. */
 	struct grid_cell last_cell;
 };
@@ -1187,7 +1191,7 @@ struct client {
 	struct event	 repeat_timer;
 
 	struct event	 click_timer;
-	u_int            click_button;
+	u_int		 click_button;
 
 	struct event	 status_timer;
 	struct screen	 status;
@@ -1271,10 +1275,10 @@ struct cmd_find_state {
 	int			 flags;
 	struct cmd_find_state	*current;
 
-	struct session          *s;
-	struct winlink          *wl;
+	struct session		*s;
+	struct winlink		*wl;
 	struct window		*w;
-	struct window_pane      *wp;
+	struct window_pane	*wp;
 	int			 idx;
 };
 
@@ -1544,7 +1548,7 @@ void		 format_defaults_paste_buffer(struct format_tree *,
 
 /* hooks.c */
 struct hook;
-struct hooks 	*hooks_get(struct session *);
+struct hooks	*hooks_get(struct session *);
 struct hooks	*hooks_create(struct hooks *);
 void		 hooks_free(struct hooks *);
 struct hook	*hooks_first(struct hooks *);
@@ -1925,17 +1929,17 @@ int	 grid_cells_equal(const struct grid_cell *, const struct grid_cell *);
 struct grid *grid_create(u_int, u_int, u_int);
 void	 grid_destroy(struct grid *);
 int	 grid_compare(struct grid *, struct grid *);
-void	 grid_collect_history(struct grid *);
-void	 grid_scroll_history(struct grid *);
+void	 grid_collect_history(struct grid *, u_int);
+void	 grid_scroll_history(struct grid *, u_int);
 void	 grid_scroll_history_region(struct grid *, u_int, u_int);
 void	 grid_clear_history(struct grid *);
 const struct grid_line *grid_peek_line(struct grid *, u_int);
 void	 grid_get_cell(struct grid *, u_int, u_int, struct grid_cell *);
 void	 grid_set_cell(struct grid *, u_int, u_int, const struct grid_cell *);
-void	 grid_clear(struct grid *, u_int, u_int, u_int, u_int);
-void	 grid_clear_lines(struct grid *, u_int, u_int);
-void	 grid_move_lines(struct grid *, u_int, u_int, u_int);
-void	 grid_move_cells(struct grid *, u_int, u_int, u_int, u_int);
+void	 grid_clear(struct grid *, u_int, u_int, u_int, u_int, u_int);
+void	 grid_clear_lines(struct grid *, u_int, u_int, u_int);
+void	 grid_move_lines(struct grid *, u_int, u_int, u_int, u_int);
+void	 grid_move_cells(struct grid *, u_int, u_int, u_int, u_int, u_int);
 char	*grid_string_cells(struct grid *, u_int, u_int, u_int,
 	     struct grid_cell **, int, int, int);
 void	 grid_duplicate_lines(struct grid *, u_int, struct grid *, u_int,
@@ -1946,16 +1950,18 @@ u_int	 grid_reflow(struct grid *, struct grid *, u_int);
 void	 grid_view_get_cell(struct grid *, u_int, u_int, struct grid_cell *);
 void	 grid_view_set_cell(struct grid *, u_int, u_int,
 	     const struct grid_cell *);
-void	 grid_view_clear_history(struct grid *);
-void	 grid_view_clear(struct grid *, u_int, u_int, u_int, u_int);
+void	 grid_view_clear_history(struct grid *, u_int);
+void	 grid_view_clear(struct grid *, u_int, u_int, u_int, u_int, u_int);
 void	 grid_view_scroll_region_up(struct grid *, u_int, u_int);
 void	 grid_view_scroll_region_down(struct grid *, u_int, u_int);
-void	 grid_view_insert_lines(struct grid *, u_int, u_int);
-void	 grid_view_insert_lines_region(struct grid *, u_int, u_int, u_int);
-void	 grid_view_delete_lines(struct grid *, u_int, u_int);
-void	 grid_view_delete_lines_region(struct grid *, u_int, u_int, u_int);
-void	 grid_view_insert_cells(struct grid *, u_int, u_int, u_int);
-void	 grid_view_delete_cells(struct grid *, u_int, u_int, u_int);
+void	 grid_view_insert_lines(struct grid *, u_int, u_int, u_int);
+void	 grid_view_insert_lines_region(struct grid *, u_int, u_int, u_int,
+	u_int);
+void	 grid_view_delete_lines(struct grid *, u_int, u_int, u_int);
+void	 grid_view_delete_lines_region(struct grid *, u_int, u_int, u_int,
+	u_int);
+void	 grid_view_insert_cells(struct grid *, u_int, u_int, u_int, u_int);
+void	 grid_view_delete_cells(struct grid *, u_int, u_int, u_int, u_int);
 char	*grid_view_string_cells(struct grid *, u_int, u_int, u_int);
 
 /* screen-write.c */
@@ -1985,22 +1991,22 @@ void	 screen_write_cursordown(struct screen_write_ctx *, u_int);
 void	 screen_write_cursorright(struct screen_write_ctx *, u_int);
 void	 screen_write_cursorleft(struct screen_write_ctx *, u_int);
 void	 screen_write_alignmenttest(struct screen_write_ctx *);
-void	 screen_write_insertcharacter(struct screen_write_ctx *, u_int);
-void	 screen_write_deletecharacter(struct screen_write_ctx *, u_int);
+void	 screen_write_insertcharacter(struct screen_write_ctx *, u_int, u_int);
+void	 screen_write_deletecharacter(struct screen_write_ctx *, u_int, u_int);
 void	 screen_write_clearcharacter(struct screen_write_ctx *, u_int);
-void	 screen_write_insertline(struct screen_write_ctx *, u_int);
-void	 screen_write_deleteline(struct screen_write_ctx *, u_int);
-void	 screen_write_clearline(struct screen_write_ctx *);
-void	 screen_write_clearendofline(struct screen_write_ctx *);
-void	 screen_write_clearstartofline(struct screen_write_ctx *);
+void	 screen_write_insertline(struct screen_write_ctx *, u_int, u_int);
+void	 screen_write_deleteline(struct screen_write_ctx *, u_int, u_int);
+void	 screen_write_clearline(struct screen_write_ctx *, u_int);
+void	 screen_write_clearendofline(struct screen_write_ctx *, u_int);
+void	 screen_write_clearstartofline(struct screen_write_ctx *, u_int);
 void	 screen_write_cursormove(struct screen_write_ctx *, u_int, u_int);
 void	 screen_write_reverseindex(struct screen_write_ctx *);
 void	 screen_write_scrollregion(struct screen_write_ctx *, u_int, u_int);
 void	 screen_write_linefeed(struct screen_write_ctx *, int);
 void	 screen_write_carriagereturn(struct screen_write_ctx *);
-void	 screen_write_clearendofscreen(struct screen_write_ctx *);
+void	 screen_write_clearendofscreen(struct screen_write_ctx *, u_int);
 void	 screen_write_clearstartofscreen(struct screen_write_ctx *);
-void	 screen_write_clearscreen(struct screen_write_ctx *);
+void	 screen_write_clearscreen(struct screen_write_ctx *, u_int);
 void	 screen_write_clearhistory(struct screen_write_ctx *);
 void	 screen_write_cell(struct screen_write_ctx *, const struct grid_cell *);
 void	 screen_write_setselection(struct screen_write_ctx *, u_char *, u_int);
diff --git a/usr.bin/tmux/tty.c b/usr.bin/tmux/tty.c
index 3ae5d3ad802..7506cbef655 100644
--- a/usr.bin/tmux/tty.c
+++ b/usr.bin/tmux/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.209 2016/10/12 13:24:07 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.210 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -55,7 +55,8 @@ static void	tty_colours_bg(struct tty *, const struct grid_cell *);
 static void	tty_region_pane(struct tty *, const struct tty_ctx *, u_int,
 		    u_int);
 static int	tty_large_region(struct tty *, const struct tty_ctx *);
-static int	tty_fake_bce(const struct tty *, const struct window_pane *);
+static int	tty_fake_bce(const struct tty *, const struct window_pane *,
+		    u_int);
 static void	tty_redraw_region(struct tty *, const struct tty_ctx *);
 static void	tty_emulate_repeat(struct tty *, enum tty_code_code,
 		    enum tty_code_code, u_int);
@@ -64,6 +65,8 @@ static void	tty_cell(struct tty *, const struct grid_cell *,
 		    const struct window_pane *);
 static void	tty_default_colours(struct grid_cell *,
 		    const struct window_pane *);
+static void	tty_default_attributes(struct tty *, const struct window_pane *,
+		    u_int);
 
 #define tty_use_acs(tty) \
 	(tty_term_has((tty)->term, TTYC_ACSC) && !((tty)->flags & TTY_UTF8))
@@ -604,17 +607,20 @@ tty_large_region(__unused struct tty *tty, const struct tty_ctx *ctx)
  * emulated.
  */
 static int
-tty_fake_bce(const struct tty *tty, const struct window_pane *wp)
+tty_fake_bce(const struct tty *tty, const struct window_pane *wp, u_int bg)
 {
 	struct grid_cell	gc;
 
+	if (tty_term_flag(tty->term, TTYC_BCE))
+		return (0);
+
 	memcpy(&gc, &grid_default_cell, sizeof gc);
 	if (wp != NULL)
 		tty_default_colours(&gc, wp);
 
-	if (gc.bg == 8)
-		return (0);
-	return (!tty_term_flag(tty->term, TTYC_BCE));
+	if (bg != 8 || gc.bg != 8)
+		return (1);
+	return (0);
 }
 
 /*
@@ -695,13 +701,13 @@ tty_draw_line(struct tty *tty, const struct window_pane *wp,
 	}
 
 	if (sx < tty->sx) {
-		tty_attributes(tty, &grid_default_cell, wp);
+		tty_default_attributes(tty, wp, 8);
 
 		tty_cursor(tty, ox + sx, oy + py);
 		if (sx != screen_size_x(s) &&
 		    ox + screen_size_x(s) >= tty->sx &&
 		    tty_term_has(tty->term, TTYC_EL) &&
-		    !tty_fake_bce(tty, wp))
+		    !tty_fake_bce(tty, wp, 8))
 			tty_putcode(tty, TTYC_EL);
 		else
 			tty_repeat_space(tty, screen_size_x(s) - sx);
@@ -759,14 +765,15 @@ tty_cmd_insertcharacter(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct window_pane	*wp = ctx->wp;
 
-	if (!tty_pane_full_width(tty, ctx) || tty_fake_bce(tty, wp) ||
-	    (!tty_term_has(tty->term, TTYC_DCH) &&
-	    !tty_term_has(tty->term, TTYC_DCH1))) {
+	if (!tty_pane_full_width(tty, ctx) ||
+	    tty_fake_bce(tty, wp, ctx->bg) ||
+	    (!tty_term_has(tty->term, TTYC_ICH) &&
+	    !tty_term_has(tty->term, TTYC_ICH1))) {
 		tty_draw_pane(tty, wp, ctx->ocy, ctx->xoff, ctx->yoff);
 		return;
 	}
 
-	tty_attributes(tty, &grid_default_cell, wp);
+	tty_default_attributes(tty, wp, ctx->bg);
 
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 
@@ -778,14 +785,15 @@ tty_cmd_deletecharacter(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct window_pane	*wp = ctx->wp;
 
-	if (!tty_pane_full_width(tty, ctx) || tty_fake_bce(tty, wp) ||
+	if (!tty_pane_full_width(tty, ctx) ||
+	    tty_fake_bce(tty, wp, ctx->bg) ||
 	    (!tty_term_has(tty->term, TTYC_DCH) &&
 	    !tty_term_has(tty->term, TTYC_DCH1))) {
 		tty_draw_pane(tty, wp, ctx->ocy, ctx->xoff, ctx->yoff);
 		return;
 	}
 
-	tty_attributes(tty, &grid_default_cell, wp);
+	tty_default_attributes(tty, wp, ctx->bg);
 
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 
@@ -801,7 +809,8 @@ tty_cmd_clearcharacter(struct tty *tty, const struct tty_ctx *ctx)
 
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 
-	if (tty_term_has(tty->term, TTYC_ECH) && !tty_fake_bce(tty, ctx->wp))
+	if (tty_term_has(tty->term, TTYC_ECH) &&
+	    !tty_fake_bce(tty, ctx->wp, ctx->bg))
 		tty_putcode1(tty, TTYC_ECH, ctx->num);
 	else {
 		for (i = 0; i < ctx->num; i++)
@@ -812,14 +821,15 @@ tty_cmd_clearcharacter(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_insertline(struct tty *tty, const struct tty_ctx *ctx)
 {
-	if (!tty_pane_full_width(tty, ctx) || tty_fake_bce(tty, ctx->wp) ||
+	if (!tty_pane_full_width(tty, ctx) ||
+	    tty_fake_bce(tty, ctx->wp, ctx->bg) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    !tty_term_has(tty->term, TTYC_IL1)) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	tty_attributes(tty, &grid_default_cell, ctx->wp);
+	tty_default_attributes(tty, ctx->wp, ctx->bg);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
@@ -830,14 +840,15 @@ tty_cmd_insertline(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_deleteline(struct tty *tty, const struct tty_ctx *ctx)
 {
-	if (!tty_pane_full_width(tty, ctx) || tty_fake_bce(tty, ctx->wp) ||
+	if (!tty_pane_full_width(tty, ctx) ||
+	    tty_fake_bce(tty, ctx->wp, ctx->bg) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    !tty_term_has(tty->term, TTYC_DL1)) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	tty_attributes(tty, &grid_default_cell, ctx->wp);
+	tty_default_attributes(tty, ctx->wp, ctx->bg);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
@@ -851,11 +862,12 @@ tty_cmd_clearline(struct tty *tty, const struct tty_ctx *ctx)
 	struct window_pane	*wp = ctx->wp;
 	struct screen		*s = wp->screen;
 
-	tty_attributes(tty, &grid_default_cell, wp);
+	tty_default_attributes(tty, wp, ctx->bg);
 
 	tty_cursor_pane(tty, ctx, 0, ctx->ocy);
 
-	if (tty_pane_full_width(tty, ctx) && !tty_fake_bce(tty, wp) &&
+	if (tty_pane_full_width(tty, ctx) &&
+	    !tty_fake_bce(tty, wp, ctx->bg) &&
 	    tty_term_has(tty->term, TTYC_EL))
 		tty_putcode(tty, TTYC_EL);
 	else
@@ -868,12 +880,13 @@ tty_cmd_clearendofline(struct tty *tty, const struct tty_ctx *ctx)
 	struct window_pane	*wp = ctx->wp;
 	struct screen		*s = wp->screen;
 
-	tty_attributes(tty, &grid_default_cell, wp);
+	tty_default_attributes(tty, wp, ctx->bg);
 
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 
 	if (tty_pane_full_width(tty, ctx) &&
-	    tty_term_has(tty->term, TTYC_EL) && !tty_fake_bce(tty, wp))
+	    tty_term_has(tty->term, TTYC_EL) &&
+	    !tty_fake_bce(tty, wp, ctx->bg))
 		tty_putcode(tty, TTYC_EL);
 	else
 		tty_repeat_space(tty, screen_size_x(s) - ctx->ocx);
@@ -882,10 +895,13 @@ tty_cmd_clearendofline(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_clearstartofline(struct tty *tty, const struct tty_ctx *ctx)
 {
-	tty_attributes(tty, &grid_default_cell, ctx->wp);
+	struct window_pane	*wp = ctx->wp;
 
-	if (ctx->xoff == 0 && tty_term_has(tty->term, TTYC_EL1) &&
-	    !tty_fake_bce(tty, ctx->wp)) {
+	tty_default_attributes(tty, wp, ctx->bg);
+
+	if (ctx->xoff == 0 &&
+	    tty_term_has(tty->term, TTYC_EL1) &&
+	    !tty_fake_bce(tty, ctx->wp, ctx->bg)) {
 		tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 		tty_putcode(tty, TTYC_EL1);
 	} else {
@@ -900,7 +916,8 @@ tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
 	if (ctx->ocy != ctx->orupper)
 		return;
 
-	if (!tty_pane_full_width(tty, ctx) || tty_fake_bce(tty, ctx->wp) ||
+	if (!tty_pane_full_width(tty, ctx) ||
+	    tty_fake_bce(tty, ctx->wp, ctx->bg) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    !tty_term_has(tty->term, TTYC_RI)) {
 		tty_redraw_region(tty, ctx);
@@ -923,7 +940,8 @@ tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
 	if (ctx->ocy != ctx->orlower)
 		return;
 
-	if (!tty_pane_full_width(tty, ctx) || tty_fake_bce(tty, wp) ||
+	if (!tty_pane_full_width(tty, ctx) ||
+	    tty_fake_bce(tty, wp, ctx->bg) ||
 	    !tty_term_has(tty->term, TTYC_CSR)) {
 		if (tty_large_region(tty, ctx))
 			wp->flags |= PANE_REDRAW;
@@ -955,13 +973,14 @@ tty_cmd_clearendofscreen(struct tty *tty, const struct tty_ctx *ctx)
 	struct screen		*s = wp->screen;
 	u_int			 i, j;
 
-	tty_attributes(tty, &grid_default_cell, wp);
+	tty_default_attributes(tty, wp, ctx->bg);
 
 	tty_region_pane(tty, ctx, 0, screen_size_y(s) - 1);
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 
 	if (tty_pane_full_width(tty, ctx) &&
-	    tty_term_has(tty->term, TTYC_EL) && !tty_fake_bce(tty, wp)) {
+	    tty_term_has(tty->term, TTYC_EL) &&
+	    !tty_fake_bce(tty, wp, ctx->bg)) {
 		tty_putcode(tty, TTYC_EL);
 		if (ctx->ocy != screen_size_y(s) - 1) {
 			tty_cursor_pane(tty, ctx, 0, ctx->ocy + 1);
@@ -995,7 +1014,8 @@ tty_cmd_clearstartofscreen(struct tty *tty, const struct tty_ctx *ctx)
 	tty_cursor_pane(tty, ctx, 0, 0);
 
 	if (tty_pane_full_width(tty, ctx) &&
-	    tty_term_has(tty->term, TTYC_EL) && !tty_fake_bce(tty, wp)) {
+	    tty_term_has(tty->term, TTYC_EL) &&
+	    !tty_fake_bce(tty, wp, ctx->bg)) {
 		for (i = 0; i < ctx->ocy; i++) {
 			tty_putcode(tty, TTYC_EL);
 			tty_emulate_repeat(tty, TTYC_CUD, TTYC_CUD1, 1);
@@ -1017,13 +1037,14 @@ tty_cmd_clearscreen(struct tty *tty, const struct tty_ctx *ctx)
 	struct screen		*s = wp->screen;
 	u_int			 i, j;
 
-	tty_attributes(tty, &grid_default_cell, wp);
+	tty_default_attributes(tty, wp, ctx->bg);
 
 	tty_region_pane(tty, ctx, 0, screen_size_y(s) - 1);
 	tty_cursor_pane(tty, ctx, 0, 0);
 
 	if (tty_pane_full_width(tty, ctx) &&
-	    tty_term_has(tty->term, TTYC_EL) && !tty_fake_bce(tty, wp)) {
+	    tty_term_has(tty->term, TTYC_EL) &&
+	    !tty_fake_bce(tty, wp, ctx->bg)) {
 		for (i = 0; i < screen_size_y(s); i++) {
 			tty_putcode(tty, TTYC_EL);
 			if (i != screen_size_y(s) - 1) {
@@ -1721,3 +1742,13 @@ tty_default_colours(struct grid_cell *gc, const struct window_pane *wp)
 			gc->bg = wgc->bg;
 	}
 }
+
+static void
+tty_default_attributes(struct tty *tty, const struct window_pane *wp, u_int bg)
+{
+	static struct grid_cell gc;
+
+	memcpy(&gc, &grid_default_cell, sizeof gc);
+	gc.bg = bg;
+	tty_attributes(tty, &gc, wp);
+}
diff --git a/usr.bin/tmux/window-choose.c b/usr.bin/tmux/window-choose.c
index 9ea4d8bdf98..6cb17b5fd0f 100644
--- a/usr.bin/tmux/window-choose.c
+++ b/usr.bin/tmux/window-choose.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window-choose.c,v 1.79 2016/10/11 13:21:59 nicm Exp $ */
+/* $OpenBSD: window-choose.c,v 1.80 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -900,7 +900,7 @@ window_choose_scroll_up(struct window_pane *wp)
 
 	screen_write_start(&ctx, wp, NULL);
 	screen_write_cursormove(&ctx, 0, 0);
-	screen_write_insertline(&ctx, 1);
+	screen_write_insertline(&ctx, 1, 8);
 	window_choose_write_line(wp, &ctx, 0);
 	if (screen_size_y(&data->screen) > 1)
 		window_choose_write_line(wp, &ctx, 1);
@@ -920,7 +920,7 @@ window_choose_scroll_down(struct window_pane *wp)
 
 	screen_write_start(&ctx, wp, NULL);
 	screen_write_cursormove(&ctx, 0, 0);
-	screen_write_deleteline(&ctx, 1);
+	screen_write_deleteline(&ctx, 1, 8);
 	window_choose_write_line(wp, &ctx, screen_size_y(s) - 1);
 	if (screen_size_y(&data->screen) > 1)
 		window_choose_write_line(wp, &ctx, screen_size_y(s) - 2);
diff --git a/usr.bin/tmux/window-clock.c b/usr.bin/tmux/window-clock.c
index 5c7cc7edd86..d0e17b51b43 100644
--- a/usr.bin/tmux/window-clock.c
+++ b/usr.bin/tmux/window-clock.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window-clock.c,v 1.20 2016/10/11 07:23:34 nicm Exp $ */
+/* $OpenBSD: window-clock.c,v 1.21 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -221,7 +221,7 @@ window_clock_draw_screen(struct window_pane *wp)
 	} else
 		strftime(tim, sizeof tim, "%H:%M", tm);
 
-	screen_write_clearscreen(&ctx);
+	screen_write_clearscreen(&ctx, 8);
 
 	if (screen_size_x(s) < 6 * strlen(tim) || screen_size_y(s) < 6) {
 		if (screen_size_x(s) >= strlen(tim) && screen_size_y(s) != 0) {
diff --git a/usr.bin/tmux/window-copy.c b/usr.bin/tmux/window-copy.c
index 9212f0bc471..9fe8452500b 100644
--- a/usr.bin/tmux/window-copy.c
+++ b/usr.bin/tmux/window-copy.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window-copy.c,v 1.158 2016/10/12 09:07:58 nicm Exp $ */
+/* $OpenBSD: window-copy.c,v 1.159 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -2052,7 +2052,7 @@ window_copy_scroll_up(struct window_pane *wp, u_int ny)
 
 	screen_write_start(&ctx, wp, NULL);
 	screen_write_cursormove(&ctx, 0, 0);
-	screen_write_deleteline(&ctx, ny);
+	screen_write_deleteline(&ctx, ny, 8);
 	window_copy_write_lines(wp, &ctx, screen_size_y(s) - ny, ny);
 	window_copy_write_line(wp, &ctx, 0);
 	if (screen_size_y(s) > 1)
@@ -2085,7 +2085,7 @@ window_copy_scroll_down(struct window_pane *wp, u_int ny)
 
 	screen_write_start(&ctx, wp, NULL);
 	screen_write_cursormove(&ctx, 0, 0);
-	screen_write_insertline(&ctx, ny);
+	screen_write_insertline(&ctx, ny, 8);
 	window_copy_write_lines(wp, &ctx, 0, ny);
 	if (s->sel.flag && screen_size_y(s) > ny)
 		window_copy_write_line(wp, &ctx, ny);
diff --git a/usr.bin/tmux/window.c b/usr.bin/tmux/window.c
index 74b36a33f9a..3dcbdf9ca87 100644
--- a/usr.bin/tmux/window.c
+++ b/usr.bin/tmux/window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window.c,v 1.169 2016/10/11 13:21:59 nicm Exp $ */
+/* $OpenBSD: window.c,v 1.170 2016/10/13 20:27:27 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1023,7 +1023,7 @@ window_pane_alternate_on(struct window_pane *wp, struct grid_cell *gc,
 	}
 	memcpy(&wp->saved_cell, gc, sizeof wp->saved_cell);
 
-	grid_view_clear(s->grid, 0, 0, sx, sy);
+	grid_view_clear(s->grid, 0, 0, sx, sy, 8);
 
 	wp->base.grid->flags &= ~GRID_HISTORY;