From 6b26f0abc074964e876b13cabf5181ca0aecca34 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 11:54:55 +0000
Subject: [PATCH 01/10] Only redraw when a feature changed.

---
 tty.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tty.c b/tty.c
index b8531c7e6..982e65669 100644
--- a/tty.c
+++ b/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.487 2026/10/14 08:33:19 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.488 2026/10/14 11:54:55 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -551,9 +551,12 @@ void
 tty_update_features(struct tty *tty)
 {
 	struct client	*c = tty->client;
+	int		 changed = 0;
 
-	if (tty_apply_features(tty->term))
+	if (tty_apply_features(tty->term)) {
 		tty_term_apply_overrides(tty->term);
+		changed = 1;
+	}
 
 	if (tty_use_margin(tty))
 		tty_putcode(tty, TTYC_ENMG);
@@ -563,13 +566,10 @@ tty_update_features(struct tty *tty)
 		tty_puts(tty, tty_term_string(tty->term, TTYC_ENFCS));
 	tty_puts(tty, tty_term_string(tty->term, TTYC_ENESC));
 
-	/*
-	 * Features might have changed since the first draw during attach. For
-	 * example, this happens when DA responses are received.
-	 */
-	server_redraw_client(c);
-
-	tty_invalidate(tty);
+	if (changed) {
+		server_redraw_client(c);
+		tty_invalidate(tty);
+	}
 }
 
 void

From 3ba4fb32cf52ab5eb3441b947d3f15785b38db6a Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 12:33:46 +0000
Subject: [PATCH 02/10] Add imagescroll feature and capability.

---
 tmux.1          |  8 ++++++--
 tmux.h          |  3 ++-
 tty-features.c  | 15 ++++++++++++++-
 tty-term.c      |  3 ++-
 window-client.c | 15 ++++++++-------
 5 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/tmux.1 b/tmux.1
index ee852c221..6267b8227 100644
--- a/tmux.1
+++ b/tmux.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.1185 2026/10/13 10:21:58 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.1186 2026/10/14 12:33:46 nicm Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 .\"
@@ -14,7 +14,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: October 13 2026 $
+.Dd $Mdocdate: October 14 2026 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -5192,6 +5192,8 @@ Supports extended keys.
 Supports focus reporting.
 .It hyperlinks
 Supports OSC 8 hyperlinks.
+.It imagescroll
+Moves image content with scroll regions.
 .It ignorefkeys
 Ignore function keys from
 .Xr terminfo 5
@@ -8972,6 +8974,8 @@ These are set automatically if the
 capability is present.
 .It Em \&Hls
 Set or clear a hyperlink annotation.
+.It Em \&Iscrl
+Indicates that the terminal moves image content with scroll regions.
 .It Em \&Nobr
 Tell
 .Nm
diff --git a/tmux.h b/tmux.h
index c42115aef..4ea5e7671 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1461 2026/10/14 10:34:14 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1462 2026/10/14 12:33:46 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -491,6 +491,7 @@ enum tty_code_code {
 	TTYC_IND,
 	TTYC_INDN,
 	TTYC_INVIS,
+	TTYC_ISCRL,
 	TTYC_KCBT,
 	TTYC_KCUB1,
 	TTYC_KCUD1,
diff --git a/tty-features.c b/tty-features.c
index 80af558d0..ee0471b46 100644
--- a/tty-features.c
+++ b/tty-features.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-features.c,v 1.48 2026/10/12 12:35:03 nicm Exp $ */
+/* $OpenBSD: tty-features.c,v 1.49 2026/10/14 12:33:46 nicm Exp $ */
 
 /*
  * Copyright (c) 2020 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -366,6 +366,17 @@ static const struct tty_feature tty_feature_kittygraphics = {
 	TERM_KITTYGRAPHICS
 };
 
+/* Terminal moves images with scroll regions. */
+static const char *const tty_feature_imagescroll_capabilities[] = {
+	"Iscrl",
+	NULL
+};
+static const struct tty_feature tty_feature_imagescroll = {
+	"imagescroll",
+	tty_feature_imagescroll_capabilities,
+	0
+};
+
 /* Terminal supports the OSC 9;4 progress bar. */
 static const char *const tty_feature_progressbar_capabilities[] = {
 	"Spb=\\E]9;4;%p1%d;%p2%d\\E\\\\",
@@ -396,6 +407,7 @@ static const struct tty_feature *const tty_features[] = {
 	&tty_feature_extkeys,
 	&tty_feature_focus,
 	&tty_feature_ignorefkeys,
+	&tty_feature_imagescroll,
 	&tty_feature_kittygraphics,
 	&tty_feature_margins,
 	&tty_feature_mouse,
@@ -635,6 +647,7 @@ tty_default_features(struct client *c, const char *name, u_int version)
 			      "extkeys,"
 			      "focus,"
 		  	      "hyperlinks,"
+			      "imagescroll,"
 			      "margins,"
 			      "sixel,"
 			      "usstyle"
diff --git a/tty-term.c b/tty-term.c
index e34a872b4..cb2a25f40 100644
--- a/tty-term.c
+++ b/tty-term.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-term.c,v 1.112 2026/10/12 10:39:05 nicm Exp $ */
+/* $OpenBSD: tty-term.c,v 1.113 2026/10/14 12:33:46 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -113,6 +113,7 @@ static const struct tty_term_code_entry tty_term_codes[] = {
 	[TTYC_IND] = { TTYCODE_STRING, "ind" },
 	[TTYC_INDN] = { TTYCODE_STRING, "indn" },
 	[TTYC_INVIS] = { TTYCODE_STRING, "invis" },
+	[TTYC_ISCRL] = { TTYCODE_FLAG, "Iscrl" },
 	[TTYC_KCBT] = { TTYCODE_STRING, "kcbt" },
 	[TTYC_KCUB1] = { TTYCODE_STRING, "kcub1" },
 	[TTYC_KCUD1] = { TTYCODE_STRING, "kcud1" },
diff --git a/window-client.c b/window-client.c
index 05bb2f801..c9234847f 100644
--- a/window-client.c
+++ b/window-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window-client.c,v 1.50 2026/10/12 12:35:03 nicm Exp $ */
+/* $OpenBSD: window-client.c,v 1.51 2026/10/14 12:33:46 nicm Exp $ */
 
 /*
  * Copyright (c) 2017 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -89,19 +89,20 @@ static const char *window_client_info_lines[] = {
 	"              #[#{E:tree-mode-border-style},acs]x#[default] "
 	WINDOW_CLIENT_FEATURE(hyperlinks) " "
 	WINDOW_CLIENT_FEATURE(ignorefkeys) " "
-	WINDOW_CLIENT_FEATURE(kittygraphics) " "
-	WINDOW_CLIENT_FEATURE(margins),
+	WINDOW_CLIENT_FEATURE(imagescroll) " "
+	WINDOW_CLIENT_FEATURE(kittygraphics),
 	"              #[#{E:tree-mode-border-style},acs]x#[default] "
+	WINDOW_CLIENT_FEATURE(margins) " "
 	WINDOW_CLIENT_FEATURE(mouse) " "
 	WINDOW_CLIENT_FEATURE(osc7) " "
-	WINDOW_CLIENT_FEATURE(overline) " "
-	WINDOW_CLIENT_FEATURE(progressbar),
+	WINDOW_CLIENT_FEATURE(overline),
 	"              #[#{E:tree-mode-border-style},acs]x#[default] "
+	WINDOW_CLIENT_FEATURE(progressbar) " "
 	WINDOW_CLIENT_FEATURE(rectfill) " "
 	WINDOW_CLIENT_FEATURE(sixel) " "
-	WINDOW_CLIENT_FEATURE(strikethrough) " "
-	WINDOW_CLIENT_FEATURE(sync),
+	WINDOW_CLIENT_FEATURE(strikethrough),
 	"              #[#{E:tree-mode-border-style},acs]x#[default] "
+	WINDOW_CLIENT_FEATURE(sync) " "
 	WINDOW_CLIENT_FEATURE(title) " "
 	WINDOW_CLIENT_FEATURE(usstyle) " "
 	WINDOW_CLIENT_FEATURE(utf8),

From abbe04fb74d62e6817a0dc8a1c0d5736e3d7425a Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 12:38:18 +0000
Subject: [PATCH 03/10] Add flags to damage struct.

---
 screen-redraw.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index 38a56b3ca..ad6f52d12 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.164 2026/10/14 10:34:14 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.165 2026/10/14 12:38:18 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -218,7 +218,10 @@ struct redraw_damage {
 	u_int				 sx;
 	u_int				 sy;
 
-	TAILQ_ENTRY(redraw_damage)	entry;
+	int				 flags;
+#define REDRAW_DAMAGE_SCROLL 0x1
+
+	TAILQ_ENTRY(redraw_damage)	 entry;
 };
 
 /*
@@ -1134,6 +1137,7 @@ redraw_collapse_damage(struct window *w)
 			x1 = rd->x + rd->sx;
 		if (rd->y + rd->sy > y1)
 			y1 = rd->y + rd->sy;
+		first->flags &= rd->flags;
 		if (rd != first) {
 			TAILQ_REMOVE(&w->damage, rd, entry);
 			free(rd);
@@ -1148,8 +1152,9 @@ redraw_collapse_damage(struct window *w)
 }
 
 /* Record window damage, merging nearby rectangles and limiting the count. */
-void
-redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
+static void
+redraw_apply_window_damage(struct window *w, u_int x, u_int y, u_int sx,
+    u_int sy, int flags)
 {
 	struct redraw_damage	*rd;
 	u_int			 x0, y0, x1, y1, area, union_area;
@@ -1182,6 +1187,7 @@ redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
 		rd->y = y0;
 		rd->sx = x1 - x0;
 		rd->sy = y1 - y0;
+		rd->flags &= flags;
 		return;
 	}
 
@@ -1190,11 +1196,19 @@ redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
 	rd->y = y;
 	rd->sx = sx;
 	rd->sy = sy;
+	rd->flags = flags;
 	TAILQ_INSERT_TAIL(&w->damage, rd, entry);
 	if (++w->damage_count > REDRAW_DAMAGE_MAX)
 		redraw_collapse_damage(w);
 }
 
+/* Record ordinary window damage. */
+void
+redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
+{
+	redraw_apply_window_damage(w, x, y, sx, sy, 0);
+}
+
 /* Mark all cached redraw scenes as out of date. */
 void
 redraw_invalidate_all_scenes(void)

From 3e6c6576ab14a9aff8c7765c7fa5e0b979d601e6 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 12:48:50 +0000
Subject: [PATCH 04/10] Track window scrolling for damage.

---
 screen-redraw.c | 36 +++++++++++++++++++++++++++++++++++-
 tmux.h          | 10 +++++++++-
 tty.c           | 10 +++++++++-
 3 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index ad6f52d12..b3c2f6f77 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.165 2026/10/14 12:38:18 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.166 2026/10/14 12:48:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1111,6 +1111,7 @@ redraw_free_damage(struct window *w)
 		free(rd);
 	}
 	w->damage_count = 0;
+	w->scroll_pending = 0;
 }
 
 /* Collapse all pending damage for a window into one rectangle. */
@@ -1209,6 +1210,39 @@ redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
 	redraw_apply_window_damage(w, x, y, sx, sy, 0);
 }
 
+/* Record damage caused by terminal scrolling. */
+void
+redraw_damage_scroll(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
+{
+	if (!w->scroll_pending) {
+		w->scroll_generation++;
+		w->scroll_pending = 1;
+	}
+	redraw_apply_window_damage(w, x, y, sx, sy, REDRAW_DAMAGE_SCROLL);
+}
+
+/* Remember whether this client used terminal scrolling for the damage. */
+void
+redraw_scroll_result(struct tty *tty, const struct tty_ctx *ctx, int failed)
+{
+	struct window_pane	*wp = ctx->arg;
+	struct window		*w;
+
+	if (wp == NULL)
+		return;
+	w = wp->window;
+	if (!w->scroll_pending)
+		return;
+	if (tty->scroll_window != w ||
+	    tty->scroll_generation != w->scroll_generation) {
+		tty->scroll_window = w;
+		tty->scroll_generation = w->scroll_generation;
+		tty->scroll_failed = 0;
+	}
+	if (failed)
+		tty->scroll_failed = 1;
+}
+
 /* Mark all cached redraw scenes as out of date. */
 void
 redraw_invalidate_all_scenes(void)
diff --git a/tmux.h b/tmux.h
index 4ea5e7671..f0c6ca61b 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1462 2026/10/14 12:33:46 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1463 2026/10/14 12:48:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1464,6 +1464,8 @@ struct window {
 
 	struct redraw_damages	 damage;
 	u_int			 damage_count;
+	uint64_t		 scroll_generation;
+	int			 scroll_pending;
 
 	struct menu_data	*menu;
 	u_int			 menu_last_px;
@@ -1835,6 +1837,10 @@ struct tty {
 
 	struct event	 key_timer;
 	struct tty_key	*key_tree;
+
+	struct window	*scroll_window;
+	uint64_t	 scroll_generation;
+	int		 scroll_failed;
 };
 
 /* Terminal command context. */
@@ -3620,6 +3626,8 @@ int	 redraw_client_has_window(struct client *, struct window *);
 void	 redraw_invalidate_scene(struct window *);
 void	 redraw_invalidate_all_scenes(void);
 void	 redraw_damage_window(struct window *, u_int, u_int, u_int, u_int);
+void	 redraw_damage_scroll(struct window *, u_int, u_int, u_int, u_int);
+void	 redraw_scroll_result(struct tty *, const struct tty_ctx *, int);
 void	 redraw_free_damage(struct window *);
 void	 redraw_client_damage(struct client *);
 int	 redraw_get_status_border_cell_type(struct redraw_span **, u_int);
diff --git a/tty.c b/tty.c
index 982e65669..feae568c4 100644
--- a/tty.c
+++ b/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.488 2026/10/14 11:54:55 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.489 2026/10/14 12:48:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1669,10 +1669,12 @@ tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
 	    !tty_term_has(tty->term, TTYC_RIN)) ||
 	    ctx->sx == 1 ||
 	    ctx->sy == 1) {
+		redraw_scroll_result(tty, ctx, 1);
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
+	redraw_scroll_result(tty, ctx, 0);
 	tty_default_attributes(tty, ctx->bg, &ctx->style_ctx);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
@@ -1697,10 +1699,12 @@ tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    ctx->sx == 1 ||
 	    ctx->sy == 1) {
+		redraw_scroll_result(tty, ctx, 1);
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
+	redraw_scroll_result(tty, ctx, 0);
 	tty_default_attributes(tty, ctx->bg, &ctx->style_ctx);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
@@ -1735,10 +1739,12 @@ tty_cmd_scrollup(struct tty *tty, const struct tty_ctx *ctx)
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    ctx->sx == 1 ||
 	    ctx->sy == 1) {
+		redraw_scroll_result(tty, ctx, 1);
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
+	redraw_scroll_result(tty, ctx, 0);
 	tty_default_attributes(tty, ctx->bg, &ctx->style_ctx);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
@@ -1773,10 +1779,12 @@ tty_cmd_scrolldown(struct tty *tty, const struct tty_ctx *ctx)
 	    !tty_term_has(tty->term, TTYC_RIN)) ||
 	    ctx->sx == 1 ||
 	    ctx->sy == 1) {
+		redraw_scroll_result(tty, ctx, 1);
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
+	redraw_scroll_result(tty, ctx, 0);
 	tty_default_attributes(tty, ctx->bg, &ctx->style_ctx);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);

From 06262fbb48c7628ffdbd0b603df1b278e1a08a97 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 12:51:00 +0000
Subject: [PATCH 05/10] Add a temporary var.

---
 screen-redraw.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index b3c2f6f77..26de8b599 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.166 2026/10/14 12:48:50 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.167 2026/10/14 12:51:00 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -2191,6 +2191,7 @@ void
 redraw_client_damage(struct client *c)
 {
 	struct window		*w = c->session->curw->window;
+	struct tty		*tty = &c->tty;
 	struct window_pane	*wp;
 	struct redraw_scene	*scene;
 	struct redraw_draw_ctx	 dctx;
@@ -2212,8 +2213,8 @@ redraw_client_damage(struct client *c)
 		wp->active_border_gc_set = 0;
 	}
 
-	tty_sync_start(&c->tty);
-	tty_update_mode(&c->tty, c->tty.mode & ~CURSOR_MODES, NULL);
+	tty_sync_start(tty);
+	tty_update_mode(tty, c->tty.mode & ~CURSOR_MODES, NULL);
 
 	TAILQ_FOREACH(rd, &w->damage, entry) {
 		x0 = (rd->x > ox) ? rd->x : ox;

From fbde17083d632a3e88622ce517711574ce7f8fa0 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 11:54:55 +0000
Subject: [PATCH 06/10] Only redraw when a feature changed.

---
 tty.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/tty.c b/tty.c
index 0f2e35a52..e9d839853 100644
--- a/tty.c
+++ b/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.487 2026/10/14 08:33:19 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.488 2026/10/14 11:54:55 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -560,12 +560,15 @@ void
 tty_update_features(struct tty *tty)
 {
 	struct client	*c = tty->client;
+	int		 changed = 0;
 
-	if (tty_apply_features(tty->term))
+	if (tty_apply_features(tty->term)) {
 		tty_term_apply_overrides(tty->term);
 #ifdef ENABLE_IMAGES
-	image_tty_update(tty);
+		image_tty_update(tty);
 #endif
+		changed = 1;
+	}
 
 	if (tty_use_margin(tty))
 		tty_putcode(tty, TTYC_ENMG);
@@ -575,13 +578,10 @@ tty_update_features(struct tty *tty)
 		tty_puts(tty, tty_term_string(tty->term, TTYC_ENFCS));
 	tty_puts(tty, tty_term_string(tty->term, TTYC_ENESC));
 
-	/*
-	 * Features might have changed since the first draw during attach. For
-	 * example, this happens when DA responses are received.
-	 */
-	server_redraw_client(c);
-
-	tty_invalidate(tty);
+	if (changed) {
+		server_redraw_client(c);
+		tty_invalidate(tty);
+	}
 }
 
 void

From ff12520ec08f1263a26f674eba99fc391dd9f1dd Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 12:33:46 +0000
Subject: [PATCH 07/10] Add imagescroll feature and capability.

---
 tmux.1          |  8 ++++++--
 tmux.h          |  3 ++-
 tty-features.c  | 15 ++++++++++++++-
 tty-term.c      |  3 ++-
 window-client.c | 15 ++++++++-------
 5 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/tmux.1 b/tmux.1
index 1d2f74a0a..0b6c48c40 100644
--- a/tmux.1
+++ b/tmux.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.1185 2026/10/13 10:21:58 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.1186 2026/10/14 12:33:46 nicm Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 .\"
@@ -14,7 +14,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: October 13 2026 $
+.Dd $Mdocdate: October 14 2026 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -5194,6 +5194,8 @@ Supports extended keys.
 Supports focus reporting.
 .It hyperlinks
 Supports OSC 8 hyperlinks.
+.It imagescroll
+Moves image content with scroll regions.
 .It ignorefkeys
 Ignore function keys from
 .Xr terminfo 5
@@ -8984,6 +8986,8 @@ These are set automatically if the
 capability is present.
 .It Em \&Hls
 Set or clear a hyperlink annotation.
+.It Em \&Iscrl
+Indicates that the terminal moves image content with scroll regions.
 .It Em \&Nobr
 Tell
 .Nm
diff --git a/tmux.h b/tmux.h
index f8c3e0d44..468c34297 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1461 2026/10/14 10:34:14 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1462 2026/10/14 12:33:46 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -499,6 +499,7 @@ enum tty_code_code {
 	TTYC_IND,
 	TTYC_INDN,
 	TTYC_INVIS,
+	TTYC_ISCRL,
 	TTYC_KCBT,
 	TTYC_KCUB1,
 	TTYC_KCUD1,
diff --git a/tty-features.c b/tty-features.c
index 1f4cd969a..3e2702f7e 100644
--- a/tty-features.c
+++ b/tty-features.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-features.c,v 1.48 2026/10/12 12:35:03 nicm Exp $ */
+/* $OpenBSD: tty-features.c,v 1.49 2026/10/14 12:33:46 nicm Exp $ */
 
 /*
  * Copyright (c) 2020 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -376,6 +376,17 @@ static const struct tty_feature tty_feature_kittygraphics = {
 	TERM_KITTYGRAPHICS
 };
 
+/* Terminal moves images with scroll regions. */
+static const char *const tty_feature_imagescroll_capabilities[] = {
+	"Iscrl",
+	NULL
+};
+static const struct tty_feature tty_feature_imagescroll = {
+	"imagescroll",
+	tty_feature_imagescroll_capabilities,
+	0
+};
+
 /* Terminal supports the OSC 9;4 progress bar. */
 static const char *const tty_feature_progressbar_capabilities[] = {
 	"Spb=\\E]9;4;%p1%d;%p2%d\\E\\\\",
@@ -406,6 +417,7 @@ static const struct tty_feature *const tty_features[] = {
 	&tty_feature_extkeys,
 	&tty_feature_focus,
 	&tty_feature_ignorefkeys,
+	&tty_feature_imagescroll,
 	&tty_feature_kittygraphics,
 	&tty_feature_margins,
 	&tty_feature_mouse,
@@ -645,6 +657,7 @@ tty_default_features(struct client *c, const char *name, u_int version)
 			      "extkeys,"
 			      "focus,"
 		  	      "hyperlinks,"
+			      "imagescroll,"
 			      "margins,"
 			      "sixel,"
 			      "usstyle"
diff --git a/tty-term.c b/tty-term.c
index 3311701ba..7415cc552 100644
--- a/tty-term.c
+++ b/tty-term.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-term.c,v 1.112 2026/10/12 10:39:05 nicm Exp $ */
+/* $OpenBSD: tty-term.c,v 1.113 2026/10/14 12:33:46 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -116,6 +116,7 @@ static const struct tty_term_code_entry tty_term_codes[] = {
 	[TTYC_IND] = { TTYCODE_STRING, "ind" },
 	[TTYC_INDN] = { TTYCODE_STRING, "indn" },
 	[TTYC_INVIS] = { TTYCODE_STRING, "invis" },
+	[TTYC_ISCRL] = { TTYCODE_FLAG, "Iscrl" },
 	[TTYC_KCBT] = { TTYCODE_STRING, "kcbt" },
 	[TTYC_KCUB1] = { TTYCODE_STRING, "kcub1" },
 	[TTYC_KCUD1] = { TTYCODE_STRING, "kcud1" },
diff --git a/window-client.c b/window-client.c
index 05bb2f801..c9234847f 100644
--- a/window-client.c
+++ b/window-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window-client.c,v 1.50 2026/10/12 12:35:03 nicm Exp $ */
+/* $OpenBSD: window-client.c,v 1.51 2026/10/14 12:33:46 nicm Exp $ */
 
 /*
  * Copyright (c) 2017 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -89,19 +89,20 @@ static const char *window_client_info_lines[] = {
 	"              #[#{E:tree-mode-border-style},acs]x#[default] "
 	WINDOW_CLIENT_FEATURE(hyperlinks) " "
 	WINDOW_CLIENT_FEATURE(ignorefkeys) " "
-	WINDOW_CLIENT_FEATURE(kittygraphics) " "
-	WINDOW_CLIENT_FEATURE(margins),
+	WINDOW_CLIENT_FEATURE(imagescroll) " "
+	WINDOW_CLIENT_FEATURE(kittygraphics),
 	"              #[#{E:tree-mode-border-style},acs]x#[default] "
+	WINDOW_CLIENT_FEATURE(margins) " "
 	WINDOW_CLIENT_FEATURE(mouse) " "
 	WINDOW_CLIENT_FEATURE(osc7) " "
-	WINDOW_CLIENT_FEATURE(overline) " "
-	WINDOW_CLIENT_FEATURE(progressbar),
+	WINDOW_CLIENT_FEATURE(overline),
 	"              #[#{E:tree-mode-border-style},acs]x#[default] "
+	WINDOW_CLIENT_FEATURE(progressbar) " "
 	WINDOW_CLIENT_FEATURE(rectfill) " "
 	WINDOW_CLIENT_FEATURE(sixel) " "
-	WINDOW_CLIENT_FEATURE(strikethrough) " "
-	WINDOW_CLIENT_FEATURE(sync),
+	WINDOW_CLIENT_FEATURE(strikethrough),
 	"              #[#{E:tree-mode-border-style},acs]x#[default] "
+	WINDOW_CLIENT_FEATURE(sync) " "
 	WINDOW_CLIENT_FEATURE(title) " "
 	WINDOW_CLIENT_FEATURE(usstyle) " "
 	WINDOW_CLIENT_FEATURE(utf8),

From d1a68c13477b4a610c1754df105ce413ea7b6ef7 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 12:38:18 +0000
Subject: [PATCH 08/10] Add flags to damage struct.

---
 screen-redraw.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index 90216c84b..504b3355a 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.164 2026/10/14 10:34:14 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.165 2026/10/14 12:38:18 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -218,7 +218,10 @@ struct redraw_damage {
 	u_int				 sx;
 	u_int				 sy;
 
-	TAILQ_ENTRY(redraw_damage)	entry;
+	int				 flags;
+#define REDRAW_DAMAGE_SCROLL 0x1
+
+	TAILQ_ENTRY(redraw_damage)	 entry;
 };
 
 /*
@@ -1134,6 +1137,7 @@ redraw_collapse_damage(struct window *w)
 			x1 = rd->x + rd->sx;
 		if (rd->y + rd->sy > y1)
 			y1 = rd->y + rd->sy;
+		first->flags &= rd->flags;
 		if (rd != first) {
 			TAILQ_REMOVE(&w->damage, rd, entry);
 			free(rd);
@@ -1148,8 +1152,9 @@ redraw_collapse_damage(struct window *w)
 }
 
 /* Record window damage, merging nearby rectangles and limiting the count. */
-void
-redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
+static void
+redraw_apply_window_damage(struct window *w, u_int x, u_int y, u_int sx,
+    u_int sy, int flags)
 {
 	struct redraw_damage	*rd;
 	u_int			 x0, y0, x1, y1, area, union_area;
@@ -1182,6 +1187,7 @@ redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
 		rd->y = y0;
 		rd->sx = x1 - x0;
 		rd->sy = y1 - y0;
+		rd->flags &= flags;
 		return;
 	}
 
@@ -1190,11 +1196,19 @@ redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
 	rd->y = y;
 	rd->sx = sx;
 	rd->sy = sy;
+	rd->flags = flags;
 	TAILQ_INSERT_TAIL(&w->damage, rd, entry);
 	if (++w->damage_count > REDRAW_DAMAGE_MAX)
 		redraw_collapse_damage(w);
 }
 
+/* Record ordinary window damage. */
+void
+redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
+{
+	redraw_apply_window_damage(w, x, y, sx, sy, 0);
+}
+
 /* Mark all cached redraw scenes as out of date. */
 void
 redraw_invalidate_all_scenes(void)

From e69cdbefefaacabce8104beecbc2d6996b7fb624 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 12:48:50 +0000
Subject: [PATCH 09/10] Track window scrolling for damage.

---
 screen-redraw.c | 36 +++++++++++++++++++++++++++++++++++-
 tmux.h          | 10 +++++++++-
 tty.c           | 10 +++++++++-
 3 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index 504b3355a..44a109fad 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.165 2026/10/14 12:38:18 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.166 2026/10/14 12:48:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1111,6 +1111,7 @@ redraw_free_damage(struct window *w)
 		free(rd);
 	}
 	w->damage_count = 0;
+	w->scroll_pending = 0;
 }
 
 /* Collapse all pending damage for a window into one rectangle. */
@@ -1209,6 +1210,39 @@ redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
 	redraw_apply_window_damage(w, x, y, sx, sy, 0);
 }
 
+/* Record damage caused by terminal scrolling. */
+void
+redraw_damage_scroll(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
+{
+	if (!w->scroll_pending) {
+		w->scroll_generation++;
+		w->scroll_pending = 1;
+	}
+	redraw_apply_window_damage(w, x, y, sx, sy, REDRAW_DAMAGE_SCROLL);
+}
+
+/* Remember whether this client used terminal scrolling for the damage. */
+void
+redraw_scroll_result(struct tty *tty, const struct tty_ctx *ctx, int failed)
+{
+	struct window_pane	*wp = ctx->arg;
+	struct window		*w;
+
+	if (wp == NULL)
+		return;
+	w = wp->window;
+	if (!w->scroll_pending)
+		return;
+	if (tty->scroll_window != w ||
+	    tty->scroll_generation != w->scroll_generation) {
+		tty->scroll_window = w;
+		tty->scroll_generation = w->scroll_generation;
+		tty->scroll_failed = 0;
+	}
+	if (failed)
+		tty->scroll_failed = 1;
+}
+
 /* Mark all cached redraw scenes as out of date. */
 void
 redraw_invalidate_all_scenes(void)
diff --git a/tmux.h b/tmux.h
index 468c34297..00293690f 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1462 2026/10/14 12:33:46 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1463 2026/10/14 12:48:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1479,6 +1479,8 @@ struct window {
 
 	struct redraw_damages	 damage;
 	u_int			 damage_count;
+	uint64_t		 scroll_generation;
+	int			 scroll_pending;
 
 	struct menu_data	*menu;
 	u_int			 menu_last_px;
@@ -1854,6 +1856,10 @@ struct tty {
 	struct event	 key_timer;
 	struct tty_key	*key_tree;
 
+	struct window	*scroll_window;
+	uint64_t	 scroll_generation;
+	int		 scroll_failed;
+
 #ifdef ENABLE_IMAGES
 	struct image_backend	*image_backend;
 	void			*image_data;
@@ -3645,6 +3651,8 @@ int	 redraw_client_has_window(struct client *, struct window *);
 void	 redraw_invalidate_scene(struct window *);
 void	 redraw_invalidate_all_scenes(void);
 void	 redraw_damage_window(struct window *, u_int, u_int, u_int, u_int);
+void	 redraw_damage_scroll(struct window *, u_int, u_int, u_int, u_int);
+void	 redraw_scroll_result(struct tty *, const struct tty_ctx *, int);
 void	 redraw_free_damage(struct window *);
 void	 redraw_client_damage(struct client *);
 int	 redraw_get_status_border_cell_type(struct redraw_span **, u_int);
diff --git a/tty.c b/tty.c
index e9d839853..2a4498a06 100644
--- a/tty.c
+++ b/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.488 2026/10/14 11:54:55 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.489 2026/10/14 12:48:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1681,10 +1681,12 @@ tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
 	    !tty_term_has(tty->term, TTYC_RIN)) ||
 	    ctx->sx == 1 ||
 	    ctx->sy == 1) {
+		redraw_scroll_result(tty, ctx, 1);
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
+	redraw_scroll_result(tty, ctx, 0);
 	tty_default_attributes(tty, ctx->bg, &ctx->style_ctx);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
@@ -1709,10 +1711,12 @@ tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    ctx->sx == 1 ||
 	    ctx->sy == 1) {
+		redraw_scroll_result(tty, ctx, 1);
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
+	redraw_scroll_result(tty, ctx, 0);
 	tty_default_attributes(tty, ctx->bg, &ctx->style_ctx);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
@@ -1747,10 +1751,12 @@ tty_cmd_scrollup(struct tty *tty, const struct tty_ctx *ctx)
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    ctx->sx == 1 ||
 	    ctx->sy == 1) {
+		redraw_scroll_result(tty, ctx, 1);
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
+	redraw_scroll_result(tty, ctx, 0);
 	tty_default_attributes(tty, ctx->bg, &ctx->style_ctx);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
@@ -1785,10 +1791,12 @@ tty_cmd_scrolldown(struct tty *tty, const struct tty_ctx *ctx)
 	    !tty_term_has(tty->term, TTYC_RIN)) ||
 	    ctx->sx == 1 ||
 	    ctx->sy == 1) {
+		redraw_scroll_result(tty, ctx, 1);
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
+	redraw_scroll_result(tty, ctx, 0);
 	tty_default_attributes(tty, ctx->bg, &ctx->style_ctx);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);

From 6dfed2fec08d0a96b402138e2bf03a357e62ee91 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 14 Oct 2026 12:51:00 +0000
Subject: [PATCH 10/10] Add a temporary var.

---
 screen-redraw.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index 44a109fad..c28926a98 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.166 2026/10/14 12:48:50 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.167 2026/10/14 12:51:00 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -2190,6 +2190,7 @@ void
 redraw_client_damage(struct client *c)
 {
 	struct window		*w = c->session->curw->window;
+	struct tty		*tty = &c->tty;
 	struct window_pane	*wp;
 	struct redraw_scene	*scene;
 	struct redraw_draw_ctx	 dctx;
@@ -2211,8 +2212,8 @@ redraw_client_damage(struct client *c)
 		wp->active_border_gc_set = 0;
 	}
 
-	tty_sync_start(&c->tty);
-	tty_update_mode(&c->tty, c->tty.mode & ~CURSOR_MODES, NULL);
+	tty_sync_start(tty);
+	tty_update_mode(tty, c->tty.mode & ~CURSOR_MODES, NULL);
 
 	TAILQ_FOREACH(rd, &w->damage, entry) {
 		x0 = (rd->x > ox) ? rd->x : ox;