From f81c41929bc9c9921b109bdd5539c0d0fc114d77 Mon Sep 17 00:00:00 2001
From: Michael Grant <mgrant@grant.org>
Date: Wed, 5 Aug 2026 13:51:07 +0100
Subject: [PATCH] Fix kitty image resize issue when the kitty image resized
 smaller than the image, the image was overflowing lines and banding.

---
 grid.c                   | 34 ++++++++++++++++++++++++++++++++++
 regress/image-support.sh | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/grid.c b/grid.c
index 1c17544b2..6bd8e3162 100644
--- a/grid.c
+++ b/grid.c
@@ -1448,6 +1448,30 @@ grid_reflow_dead(struct grid_line *gl)
 	gl->flags = GRID_LINE_DEAD;
 }
 
+/* Image rows are cell-aligned and must not be reflowed like text. */
+static int
+grid_reflow_has_image(struct grid_line *gl)
+{
+	struct grid_cell	 gc;
+	u_int			 i;
+
+	if (~gl->flags & GRID_LINE_EXTENDED)
+		return (0);
+	for (i = 0; i < gl->cellused; i++) {
+		grid_get_cell1(gl, i, &gc);
+#ifdef ENABLE_IMAGES
+		if (gc.flags & GRID_FLAG_IMAGE)
+			return (1);
+#endif
+		/* Kitty Unicode placeholder base character (U+10EEEE). */
+		if (gc.data.size >= 4 && gc.data.data[0] == 0xf4 &&
+		    gc.data.data[1] == 0x8e && gc.data.data[2] == 0xbb &&
+		    gc.data.data[3] == 0xae)
+			return (1);
+	}
+	return (0);
+}
+
 /* Add lines, return the first new one. */
 static struct grid_line *
 grid_reflow_add(struct grid *gd, u_int n)
@@ -1510,6 +1534,10 @@ grid_reflow_join(struct grid *target, struct grid *gd, u_int sx, u_int yy,
 			break;
 		line = yy + 1 + lines;
 
+		/* Do not join wrapped text to a cell-aligned image row. */
+		if (grid_reflow_has_image(&gd->linedata[line]))
+			break;
+
 		/* If the next line is empty, skip it. */
 		if (~gd->linedata[line].flags & GRID_LINE_WRAPPED)
 			wrapped = 0;
@@ -1681,6 +1709,12 @@ grid_reflow(struct grid *gd, u_int sx)
 		if (gl->flags & GRID_LINE_DEAD)
 			continue;
 
+		/* Keep image markers at their original cell coordinates. */
+		if (grid_reflow_has_image(gl)) {
+			grid_reflow_move(target, gl);
+			continue;
+		}
+
 		/*
 		 * Work out the width of this line. at is the point at which
 		 * the available width is hit, and width is the full line
diff --git a/regress/image-support.sh b/regress/image-support.sh
index b4e59ed7b..39e1ad3d7 100755
--- a/regress/image-support.sh
+++ b/regress/image-support.sh
@@ -143,4 +143,42 @@ $TMUX capture-pane -pS0 -E3 >$TMP || exit 1
 [ "$(sed -n 2p $TMP)" = "*" ] || exit 1
 [ "$(sed -n 3p $TMP)" = "@" ] || exit 1
 
+# Image marker rows remain cell-aligned when a narrower terminal causes text
+# reflow. The ten-column rows are clipped to five columns, not split into four
+# wrapped rows.
+$TMUX2 new-window -d "
+	printf '\033_Ga=T,q=2,C=1,f=32,s=1,v=2,c=10,r=2;/wAA//////8=\033\\'
+	sleep 10" || exit 1
+$TMUX2 select-window -t:3 || exit 1
+sleep 1
+$TMUX resize-window -x 5 -y 4 || exit 1
+sleep 1
+[ "$($TMUX2 display-message -p '#{window_width}x#{window_height}')" = "5x4" ] || exit 1
+$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
+[ "$(sed -n 1p $TMP)" = "....." ] || exit 1
+[ "$(sed -n 2p $TMP)" = "@@@@@" ] || exit 1
+[ -z "$(sed -n 3p $TMP)" ] || exit 1
+
+# Kitty virtual placements use U+10EEEE placeholder cells. Keep their rows at
+# fixed coordinates when narrowing the terminal, clipping instead of reflowing
+# the second half onto the following row.
+$TMUX resize-window -x 10 -y 4 || exit 1
+sleep 1
+$TMUX2 new-window -d "
+	printf '\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205'
+	printf '\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205'
+	sleep 10" || exit 1
+$TMUX2 select-window -t:4 || exit 1
+sleep 1
+$TMUX resize-window -x 5 -y 4 || exit 1
+sleep 1
+$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
+[ -n "$(sed -n 1p $TMP)" ] || exit 1
+[ -z "$(sed -n 2p $TMP)" ] || exit 1
+$TMUX resize-window -x 10 -y 4 || exit 1
+sleep 1
+$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
+[ "$(sed -n 1p $TMP | wc -c)" = 61 ] || exit 1
+[ -z "$(sed -n 2p $TMP)" ] || exit 1
+
 exit 0