From 58e498c9d3de650d2b802712bf24f8e572ccd1c9 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Wed, 21 Jan 2026 15:35:33 +0000
Subject: [PATCH 1/2] Use right cell for empty check.

---
 tty-draw.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tty-draw.c b/tty-draw.c
index 3d77d4a1..a3712161 100644
--- a/tty-draw.c
+++ b/tty-draw.c
@@ -89,7 +89,7 @@ tty_draw_line_clear(struct tty *tty, u_int px, u_int py, u_int nx,
 
 /* Is this cell empty? */
 static u_int
-tty_draw_line_get_empty(struct grid_cell *gc, u_int nx)
+tty_draw_line_get_empty(const struct grid_cell *gc, u_int nx)
 {
 	u_int	empty = 0;
 
@@ -113,7 +113,8 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
     struct colour_palette *palette)
 {
 	struct grid		*gd = s->grid;
-	struct grid_cell	 gc, *gcp, ngc, last;
+	struct grid_cell	 gc, ngc, last;
+	const struct grid_cell	*gcp;
 	struct grid_line	*gl;
 	u_int			 i, j, last_i, cx, ex, width;
 	u_int			 cellsize, bg;
@@ -233,7 +234,7 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
 			if (i >= ex)
 				empty = 1;
 			else
-				empty = tty_draw_line_get_empty(&gc, nx - i);
+				empty = tty_draw_line_get_empty(gcp, nx - i);
 
 			/* Work out the next state. */
 			if (empty != 0)
@@ -242,7 +243,7 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
 				next_state = TTY_DRAW_LINE_SAME;
 			else if (gcp->flags & GRID_FLAG_PADDING)
 				next_state = TTY_DRAW_LINE_PAD;
-			else if (grid_cells_look_equal(&gc, &last)) {
+			else if (grid_cells_look_equal(gcp, &last)) {
 				if (gcp->data.size > (sizeof buf) - len)
 					next_state = TTY_DRAW_LINE_FLUSH;
 				else

From 7730d38339f43d48246bcc7990a40bf9cb26b250 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Wed, 21 Jan 2026 15:58:11 +0000
Subject: [PATCH 2/2] Skip correct width when moving to next position.

---
 tty-draw.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/tty-draw.c b/tty-draw.c
index a3712161..ed831677 100644
--- a/tty-draw.c
+++ b/tty-draw.c
@@ -169,11 +169,15 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
 				break;
 		}
 		if (i == 0)
-			bg = gc.bg;
-		else if (screen_select_cell(s, &ngc, &gc))
-			bg = ngc.bg;
-		else
 			bg = defaults->bg;
+		else {
+			bg = gc.bg;
+			if (gc.flags & GRID_FLAG_SELECTED) {
+				memcpy(&ngc, &gc, sizeof ngc);
+				if (screen_select_cell(s, &ngc, &gc))
+					bg = ngc.bg;
+			}
+		}
 		tty_attributes(tty, &last, defaults, palette, s->hyperlinks);
 		log_debug("%s: clearing %u padding cells", __func__, cx);
 		tty_draw_line_clear(tty, atx, aty, cx, defaults, bg, 0);
@@ -227,8 +231,11 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
 			gcp = tty_check_codeset(tty, &gc);
 
 			/* And for selection. */
-			if (screen_select_cell(s, &ngc, gcp))
-				gcp = &ngc;
+			if (gcp->flags & GRID_FLAG_SELECTED) {
+				memcpy(&ngc, gcp, sizeof ngc);
+				if (screen_select_cell(s, &ngc, gcp))
+					gcp = &ngc;
+			}
 
 			/* Work out the the empty width. */
 			if (i >= ex)
@@ -303,7 +310,7 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
 		if (empty != 0)
 			i += empty;
 		else
-			i++;
+			i += gcp->data.width;
 	}
 
 	tty->flags = (tty->flags & ~TTY_NOCURSOR)|flags;