From 7383c04205fc37c18f0e047a07d7273790784473 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sat, 27 Jun 2026 10:05:38 +0000
Subject: [PATCH 01/14] Preseve prompt flags across line clear, from Aung Myo
 Kyaw.

---
 cmd-split-window.c | 4 ++--
 screen-write.c     | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/cmd-split-window.c b/cmd-split-window.c
index cdc42cefe..5d21895c6 100644
--- a/cmd-split-window.c
+++ b/cmd-split-window.c
@@ -41,8 +41,8 @@ const struct cmd_entry cmd_new_pane_entry = {
 
 	.args = { "bB:c:de:EfF:hIkl:Lm:p:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
 	.usage = "[-bdefhIklPvWZ] [-B border-lines] "
-		  "[-c start-directory] [-e environment] "
-		  "[-F format] [-l size] [-m message] [-p percentage] "
+		 "[-c start-directory] [-e environment] "
+		 "[-F format] [-l size] [-m message] [-p percentage] "
 		 "[-s style] [-S active-border-style] "
 		 "[-R inactive-border-style] [-T title] [-x width] [-y height] "
 		 "[-X x-position] [-Y y-position] " CMD_TARGET_PANE_USAGE " "
diff --git a/screen-write.c b/screen-write.c
index 45d126a6f..ba7ffd930 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -1494,12 +1494,16 @@ screen_write_clearline(struct screen_write_ctx *ctx, u_int bg)
 	struct grid_line		*gl;
 	u_int				 sx = screen_size_x(s);
 	struct screen_write_citem	*ci = ctx->item;
+	u_int				 flags;
 
 	gl = grid_get_line(s->grid, s->grid->hsize + s->cy);
 	if (gl->cellsize == 0 && COLOUR_DEFAULT(bg))
 		return;
 
+	flags = gl->flags & (GRID_LINE_START_PROMPT|GRID_LINE_START_OUTPUT);
 	grid_view_clear(s->grid, 0, s->cy, sx, 1, bg);
+	gl = grid_get_line(s->grid, s->grid->hsize + s->cy);
+	gl->flags |= flags;
 
 	screen_write_collect_clear(ctx, s->cy, 1);
 	ci->x = 0;

From dd02989e88b700b18ffa0230b49e245ca340ee48 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sat, 27 Jun 2026 10:16:15 +0000
Subject: [PATCH 02/14] Invalidate scene when changing window Z index, from
 Dane Jensen.

---
 window.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/window.c b/window.c
index ac71a72bd..1965685b6 100644
--- a/window.c
+++ b/window.c
@@ -624,6 +624,7 @@ window_redraw_active_switch(struct window *w, struct window_pane *wp)
 			TAILQ_REMOVE(&w->z_index, wp, zentry);
 			TAILQ_INSERT_HEAD(&w->z_index, wp, zentry);
 			wp->flags |= PANE_REDRAW;
+			redraw_invalidate_scene(w);
 		}
 
 		wp = w->active;

From e24969b4227266e5775bdc9688c14c937e2713df Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sat, 27 Jun 2026 10:18:32 +0000
Subject: [PATCH 03/14] Add a helper to swap a node into the place of a leaf,
 from Dane Jensen.

---
 layout.c | 55 ++++++++++++++++++++++++++++++++++---------------------
 tmux.h   |  2 ++
 2 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/layout.c b/layout.c
index 569616f1f..d5dcf1ccf 100644
--- a/layout.c
+++ b/layout.c
@@ -1184,6 +1184,32 @@ layout_resize_child_cells(struct window *w, struct layout_cell *lc)
 	}
 }
 
+/*
+ * Replaces the provided layout cell with a new node of the specified type and
+ * inserts the cell into it. Used when creating new cells requires a different
+ * layout type, or when the root layout is a window pane.
+ */
+struct layout_cell *
+layout_replace_with_node(struct window *w, struct layout_cell *lc,
+    enum layout_type type)
+{
+	struct layout_cell	*lcparent;
+
+	lcparent = layout_create_cell(lc->parent);
+	layout_make_node(lcparent, type);
+	layout_set_size(lcparent, lc->sx, lc->sy, lc->xoff, lc->yoff);
+	if (lc->parent == NULL)
+		w->layout_root = lcparent;
+	else
+		TAILQ_REPLACE(&lc->parent->cells, lc, lcparent, entry);
+
+	/* Insert the old cell. */
+	lc->parent = lcparent;
+	TAILQ_INSERT_HEAD(&lcparent->cells, lc, entry);
+
+	return (lcparent);
+}
+
 /*
  * Split a pane into two. size is a hint, or -1 for default half/half
  * split. This must be followed by layout_assign_pane before much else happens!
@@ -1315,17 +1341,7 @@ layout_split_pane(struct window_pane *wp, enum layout_type type, int size,
 		 */
 
 		/* Create and insert the replacement parent. */
-		lcparent = layout_create_cell(lc->parent);
-		layout_make_node(lcparent, type);
-		layout_set_size(lcparent, sx, sy, xoff, yoff);
-		if (lc->parent == NULL)
-			wp->window->layout_root = lcparent;
-		else
-			TAILQ_REPLACE(&lc->parent->cells, lc, lcparent, entry);
-
-		/* Insert the old cell. */
-		lc->parent = lcparent;
-		TAILQ_INSERT_HEAD(&lcparent->cells, lc, entry);
+		lcparent = layout_replace_with_node(wp->window, lc, type);
 
 		/* Create the new child cell. */
 		lcnew = layout_create_cell(lcparent);
@@ -1384,14 +1400,7 @@ layout_floating_pane(struct window *w, struct window_pane *wp, u_int sx,
 		* Adding a pane to a root that isn't node. Must create and
 		* insert a new root.
 		*/
-		lcparent = layout_create_cell(NULL);
-		layout_make_node(lcparent, LAYOUT_TOPBOTTOM);
-		layout_set_size(lcparent, w->sx, w->sy, 0, 0);
-		w->layout_root = lcparent;
-
-		/* Insert the old cell. */
-		lc->parent = lcparent;
-		TAILQ_INSERT_HEAD(&lcparent->cells, lc, entry);
+		lcparent = layout_replace_with_node(w, lc, LAYOUT_TOPBOTTOM);
 	}
 
 	lcnew = layout_create_cell(lcparent);
@@ -1712,7 +1721,11 @@ layout_remove_tile(struct window *w, struct layout_cell *lc)
 		layout_resize_adjust(w, lcneighbour, type, change);
 	}
 
-	/* Zeroing out the cell geometry until the cell is retiled. */
-	layout_set_size(lc, 0, 0, 0, 0);
+	/*
+	 * Zeroing out the cell geometry until the cell is retiled unless this
+	 * is the top level node.
+	 */
+	if (lc->parent != NULL)
+		layout_set_size(lc, 0, 0, 0, 0);
 	return (1);
 }
diff --git a/tmux.h b/tmux.h
index d80e9b793..b03525c7e 100644
--- a/tmux.h
+++ b/tmux.h
@@ -3643,6 +3643,8 @@ int		 layout_resize_floating_pane_to(struct window_pane *,
 		     enum layout_type, u_int, char **);
 void		 layout_assign_pane(struct layout_cell *, struct window_pane *,
 		     int);
+struct layout_cell *layout_replace_with_node(struct window *,
+		     struct layout_cell *, enum layout_type);
 struct layout_cell *layout_split_pane(struct window_pane *, enum layout_type,
 		     int, int);
 struct layout_cell *layout_floating_pane(struct window *, struct window_pane *,

From 5e0b0a2aa3cc5da7f724ef03eab5c60636545890 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sat, 27 Jun 2026 10:21:26 +0000
Subject: [PATCH 04/14] Pulled code out of layout_split_pane for reuse and
 added layout_insert_tile. From Dane Jensen.

---
 layout.c | 221 ++++++++++++++++++++++++++++++++++++++++++++-----------
 tmux.h   |   7 ++
 2 files changed, 184 insertions(+), 44 deletions(-)

diff --git a/layout.c b/layout.c
index d5dcf1ccf..279f504af 100644
--- a/layout.c
+++ b/layout.c
@@ -31,8 +31,9 @@
  * a cell which contains a list of cells, and 'leaf' to refer to a cell that
  * contains a window pane. A leaf is considered to be 'tiled' if it is to be
  * drawn as a part of the tiled layout. A 'neighbour' is a sibling that is also
- * tiled. A cell's 'split' size refers to the side that is shortened when
- * splitting it, determined by the parent's type.
+ * tiled or a node that contains a tiled leaf in a subtree. A cell's 'split'
+ * size refers to the side that is shortened when splitting it, determined by
+ * the parent's type.
  *
  * Each window has a pointer to the root of its layout tree (containing its
  * panes), every pane has a pointer back to the cell containing it, and each
@@ -296,6 +297,27 @@ layout_cell_is_first_tiled(struct layout_cell *lc)
 	return (lcchild == lc);
 }
 
+static struct layout_cell *
+layout_cell_get_first_tiled(struct layout_cell *lc)
+{
+	struct layout_cell	*lcchild, *lcchild2;
+
+	if (layout_cell_is_tiled(lc))
+		return (lc);
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (NULL);
+
+	TAILQ_FOREACH(lcchild, &lc->cells, entry) {
+		if (layout_cell_is_tiled(lcchild))
+			return (lcchild);
+		if (lcchild->type != LAYOUT_WINDOWPANE) {
+			lcchild2 = layout_cell_get_first_tiled(lcchild);
+			if (lcchild2 != NULL)
+				return (lcchild2);
+		}
+	}
+	return (NULL);
+}
 
 /* Fix cell offsets for a child cell. */
 static void
@@ -609,6 +631,20 @@ layout_resize_adjust(struct window *w, struct layout_cell *lc,
 	}
 }
 
+/* Resizes a cell to a specified size */
+void
+layout_resize_set_size(struct window *w, struct layout_cell *lc,
+    enum layout_type type, u_int size)
+{
+	int	change;
+
+	if (type == LAYOUT_LEFTRIGHT)
+		change = size - lc->sx;
+	else
+		change = size - lc->sy;
+	layout_resize_adjust(w, lc, type, change);
+}
+
 /* Find and return the nearest neighbour to a cell in a specific direction. */
 static struct layout_cell *
 layout_cell_get_neighbour_direction(struct layout_cell *lc, int direction)
@@ -1210,6 +1246,75 @@ layout_replace_with_node(struct window *w, struct layout_cell *lc,
 	return (lcparent);
 }
 
+/* Checks if there is enough space for two new panes. */
+int
+layout_split_check_space(struct window_pane *wp, struct layout_cell *lc,
+   enum layout_type type)
+{
+	struct style	*sb_style = &wp->scrollbar_style;
+	u_int		 minimum, sx = lc->sx, sy = lc->sy;
+	int		 scrollbars, status;
+
+	if (lc->flags & LAYOUT_CELL_FLOATING)
+		fatalx("floating cells cannot be split");
+
+	status = window_get_pane_status(wp->window);
+	scrollbars = options_get_number(wp->window->options, "pane-scrollbars");
+
+	switch (type) {
+	case LAYOUT_LEFTRIGHT:
+		if (scrollbars) {
+			minimum = PANE_MINIMUM * 2 + sb_style->width +
+			    sb_style->pad;
+		} else
+			minimum = PANE_MINIMUM * 2 + 1;
+		if (sx < minimum)
+			return (0);
+		break;
+	case LAYOUT_TOPBOTTOM:
+		if (layout_add_horizontal_border(wp->window, lc, status))
+			minimum = PANE_MINIMUM * 2 + 2;
+		else
+			minimum = PANE_MINIMUM * 2 + 1;
+		if (sy < minimum)
+			return (0);
+		break;
+	default:
+		fatalx("bad layout type");
+	}
+
+	return (1);
+}
+
+/* Calculates the new cell sizes when splitting a pane. */
+void
+layout_split_sizes(struct layout_cell *lc, int size, int before,
+    enum layout_type type, u_int *size1, u_int *size2, u_int *saved_size)
+{
+	u_int	s1, s2, ss;
+	u_int	sx = lc->sx, sy = lc->sy;
+
+	if (type == LAYOUT_LEFTRIGHT)
+		ss = sx;
+	else
+		ss = sy;
+	if (size < 0)
+		s2 = ((ss + 1) / 2) - 1;
+	else if (before)
+		s2 = ss - size - 1;
+	else
+		s2 = size;
+	if (s2 < PANE_MINIMUM)
+		s2 = PANE_MINIMUM;
+	else if (s2 > sx - 2)
+		s2 = ss - 2;
+	s1 = ss - 1 - s2;
+
+	*size1 = s1;
+	*size2 = s2;
+	*saved_size = ss;
+}
+
 /*
  * Split a pane into two. size is a hint, or -1 for default half/half
  * split. This must be followed by layout_assign_pane before much else happens!
@@ -1219,11 +1324,10 @@ layout_split_pane(struct window_pane *wp, enum layout_type type, int size,
     int flags)
 {
 	struct layout_cell	*lc, *lcparent, *lcnew, *lc1, *lc2;
-	struct style		*sb_style = &wp->scrollbar_style;
-	u_int			 sx, sy, xoff, yoff, size1, size2, minimum;
+	u_int			 sx, sy, xoff, yoff, size1, size2;
 	u_int			 new_size, saved_size, resize_first = 0;
-	int			 full_size = (flags & SPAWN_FULLSIZE), status;
-	int			 scrollbars;
+	int			 full_size = (flags & SPAWN_FULLSIZE);
+	int			 before = (flags & SPAWN_BEFORE);
 
 	/*
 	 * If full_size is specified, add a new cell at the top of the window
@@ -1233,8 +1337,6 @@ layout_split_pane(struct window_pane *wp, enum layout_type type, int size,
 		lc = wp->window->layout_root;
 	else
 		lc = wp->layout_cell;
-	status = window_get_pane_status(wp->window);
-	scrollbars = options_get_number(wp->window->options, "pane-scrollbars");
 
 	/* Copy the old cell size. */
 	sx = lc->sx;
@@ -1243,47 +1345,14 @@ layout_split_pane(struct window_pane *wp, enum layout_type type, int size,
 	yoff = lc->yoff;
 
 	/* Check there is enough space for the two new panes. */
-	switch (type) {
-	case LAYOUT_LEFTRIGHT:
-		if (scrollbars) {
-			minimum = PANE_MINIMUM * 2 + sb_style->width +
-			    sb_style->pad;
-		} else
-			minimum = PANE_MINIMUM * 2 + 1;
-		if (sx < minimum)
-			return (NULL);
-		break;
-	case LAYOUT_TOPBOTTOM:
-		if (layout_add_horizontal_border(wp->window, lc, status))
-			minimum = PANE_MINIMUM * 2 + 2;
-		else
-			minimum = PANE_MINIMUM * 2 + 1;
-		if (sy < minimum)
-			return (NULL);
-		break;
-	default:
-		fatalx("bad layout type");
-	}
+	if (!layout_split_check_space(wp, lc, type))
+		return (NULL);
 
 	/*
 	 * Calculate new cell sizes. size is the target size or -1 for middle
 	 * split, size1 is the size of the top/left and size2 the bottom/right.
 	 */
-	if (type == LAYOUT_LEFTRIGHT)
-		saved_size = sx;
-	else
-		saved_size = sy;
-	if (size < 0)
-		size2 = ((saved_size + 1) / 2) - 1;
-	else if (flags & SPAWN_BEFORE)
-		size2 = saved_size - size - 1;
-	else
-		size2 = size;
-	if (size2 < PANE_MINIMUM)
-		size2 = PANE_MINIMUM;
-	else if (size2 > saved_size - 2)
-		size2 = saved_size - 2;
-	size1 = saved_size - 1 - size2;
+	layout_split_sizes(lc, size, before, type, &size1, &size2, &saved_size);
 
 	/* Which size are we using? */
 	if (flags & SPAWN_BEFORE)
@@ -1729,3 +1798,67 @@ layout_remove_tile(struct window *w, struct layout_cell *lc)
 		layout_set_size(lc, 0, 0, 0, 0);
 	return (1);
 }
+
+/*
+ * Inserts a cell back into the tiled layout by taking half the space from its
+ * nearest neighbour.
+ */
+int
+layout_insert_tile(struct window *w, struct layout_cell *lc)
+{
+	struct layout_cell	*lcneighbour, *lctiled, *lcparent;
+	enum layout_type	 type;
+	u_int			 size1, size2, saved_size;
+
+	if (lc == NULL)
+		fatalx("layout cell cannot be null when tiling");
+
+	lcparent = lc->parent;
+	if (lc->flags & LAYOUT_CELL_FLOATING)
+		return (1);
+
+	if (lcparent == NULL) {
+		/* Only pane in the layout. */
+		layout_set_size(lc, w->sx, w->sy, 0, 0);
+		return (1);
+	}
+
+	type = lcparent->type;
+	lcneighbour = layout_cell_get_neighbour(lc);
+	if (lcneighbour == NULL) {
+		/*
+		 * This will become the only visible cell in the parent.
+		 * Tile the parent, then set the child's 'split' size.
+		 */
+		layout_insert_tile(w, lcparent);
+		if (type == LAYOUT_LEFTRIGHT)
+			size1 = lcparent->sx;
+		else
+			size1 = lcparent->sy;
+		layout_resize_set_size(w, lc, type, size1);
+	} else {
+		/*
+		 * If the neighbour is a node, a tiled child in the subtree of
+		 * the neighbour is needed to check for space.
+		 */
+		lctiled = layout_cell_get_first_tiled(lcneighbour);
+		if (!layout_split_check_space(lctiled->wp, lcneighbour, type))
+			return (0);
+		layout_split_sizes(lcneighbour, -1, 0, type, &size1, &size2,
+		    &saved_size);
+		layout_resize_set_size(w, lc, type, size1);
+		layout_resize_set_size(w, lcneighbour, type, size2);
+	}
+
+	/* Setting opposite of the 'split' size to that of the parent. */
+	if (lcparent->type == LAYOUT_LEFTRIGHT) {
+		size1 = lcparent->sy;
+		type = LAYOUT_TOPBOTTOM;
+	} else {
+		size1 = lcparent->sx;
+		type = LAYOUT_LEFTRIGHT;
+	}
+	layout_resize_set_size(w, lc, type, size1);
+
+	return (1);
+}
diff --git a/tmux.h b/tmux.h
index b03525c7e..869936e68 100644
--- a/tmux.h
+++ b/tmux.h
@@ -3629,6 +3629,8 @@ void		 layout_fix_offsets(struct window *);
 void		 layout_fix_panes(struct window *, struct window_pane *);
 void		 layout_resize_adjust(struct window *, struct layout_cell *,
 		     enum layout_type, int);
+void		 layout_resize_set_size(struct window *, struct layout_cell *,
+		     enum layout_type, u_int);
 struct layout_cell *layout_cell_get_neighbour(struct layout_cell *);
 void		 layout_init(struct window *, struct window_pane *);
 void		 layout_free(struct window *);
@@ -3643,6 +3645,10 @@ int		 layout_resize_floating_pane_to(struct window_pane *,
 		     enum layout_type, u_int, char **);
 void		 layout_assign_pane(struct layout_cell *, struct window_pane *,
 		     int);
+int		 layout_split_check_space(struct window_pane *,
+		     struct layout_cell *, enum layout_type);
+void		 layout_split_sizes(struct layout_cell *, int, int,
+		     enum layout_type, u_int *, u_int *, u_int *);
 struct layout_cell *layout_replace_with_node(struct window *,
 		     struct layout_cell *, enum layout_type);
 struct layout_cell *layout_split_pane(struct window_pane *, enum layout_type,
@@ -3661,6 +3667,7 @@ int		 layout_floating_args_parse(struct cmdq_item *, struct args *,
 		     enum pane_lines, struct window *, u_int *, u_int *, int *,
 		     int *, char **);
 int		 layout_remove_tile(struct window *, struct layout_cell *);
+int		 layout_insert_tile(struct window *, struct layout_cell *);
 
 /* layout-custom.c */
 char		*layout_dump(struct window *, struct layout_cell *);

From 79f0f97495ff9a53b14cec8b058312c3f506ea67 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sat, 27 Jun 2026 10:23:14 +0000
Subject: [PATCH 05/14] Make split-window create a new floating pane if used in
 a floating pane, rather than just complaining. Also improve documentation.
 From Dane Jensen.

---
 cmd-split-window.c |   2 +-
 tmux.1             | 219 ++++++++++++++++++++++++++-------------------
 2 files changed, 128 insertions(+), 93 deletions(-)

diff --git a/cmd-split-window.c b/cmd-split-window.c
index 5d21895c6..6c2c61252 100644
--- a/cmd-split-window.c
+++ b/cmd-split-window.c
@@ -96,7 +96,7 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	if (cmd_get_entry(self) == &cmd_new_pane_entry)
 		is_floating = !args_has(args, 'L');
 	else
-		is_floating = 0;
+		is_floating = window_pane_is_floating(wp);
 
 	flags = is_floating ? SPAWN_FLOATING : 0;
 	if (args_has(args, 'b'))
diff --git a/tmux.1 b/tmux.1
index a0ec81784..63809bac1 100644
--- a/tmux.1
+++ b/tmux.1
@@ -2742,6 +2742,15 @@ and
 .Fl Y
 options set the position of the upper-left corner of the pane.
 If omitted, new floating panes are cascaded from the top-left of the window.
+The
+.Fl x ,
+.Fl y ,
+.Fl X ,
+and
+.Fl Y
+options may be followed by
+.Ql %
+to specify a percentage of the window size.
 .Pp
 If the pane had previously been floating, the position and sizes are restored
 from the saved values not specified by the
@@ -3586,7 +3595,7 @@ but a different format may be specified with
 .Fl F .
 .Tg newp
 .It Xo Ic new\-pane
-.Op Fl bdefhIkPvWZ
+.Op Fl bdefhIkLPvWZ
 .Op Fl B Ar border\-lines
 .Op Fl c Ar start\-directory
 .Op Fl e Ar environment
@@ -3599,101 +3608,49 @@ but a different format may be specified with
 .Op Fl S Ar active\-border\-style
 .Op Fl t Ar target\-pane
 .Op Fl T Ar title
+.Op Fl x Ar width
+.Op Fl y Ar height
+.Op Fl X Ar x-position
+.Op Fl Y Ar y-position
 .Op Ar shell\-command Op Ar argument ...
 .Xc
 .D1 Pq alias: Ic newp
-Create a new pane.
-The new pane is created by splitting
-.Ar target\-pane .
-If
-.Fl d
-is given, the session does not make the new pane the current pane.
-.Fl Z
-zooms if the window is not zoomed, or keeps it zoomed if already zoomed.
-.Fl s
-sets the style for the pane content.
-.Fl S
-sets the border style when the pane is active and
-.Fl R
-sets the border style when the pane is inactive (see
-.Sx STYLES ) .
-.Fl T
-sets the pane title.
+Creates a new floating pane.
+The
+.Fl x
+and
+.Fl y
+options set the width and height of the floating pane in columns and lines
+respectively.
+The default is half the window width and a quarter the window height.
+The
+.Fl X
+and
+.Fl Y
+options set the position of the upper-left corner of the pane.
+If omitted, new floating panes are cascaded from the top-left of the window.
+The
+.Fl x ,
+.Fl y ,
+.Fl X ,
+and
+.Fl Y
+options may be followed by
+.Ql %
+to specify a percentage of the window size.
 .Fl B
 sets the pane border lines for floating panes; see
 .Ic pane\-border\-lines .
 .Pp
-.Fl h
-does a horizontal split and
-.Fl v
-a vertical split; if neither is specified,
-.Fl v
-is assumed.
 The
-.Fl l
-option specifies the size of the new pane in lines (for vertical split) or in
-columns (for horizontal split);
-.Ar size
-may be followed by
-.Ql %
-to specify a percentage of the available space.
-.Fl p
-is a shorthand option for this.
-The
-.Fl b
-option causes the new pane to be created to the left of or above
-.Ar target\-pane .
-The
-.Fl f
-option creates a new pane spanning the full window height (with
-.Fl h )
-or full window width (with
-.Fl v ) ,
-instead of splitting the active pane.
-.Pp
-.Fl k
-keeps the pane open after the optional
-.Ar shell\-command
-exits and waits for a key to be pressed before closing it.
-The message shown is controlled by the
-.Ic remain\-on\-exit\-format
-option.
-.Fl m Ar message
-is equivalent to
-.Fl k
-but also sets the
-.Ic remain\-on\-exit\-format
-option for this pane to
-.Ar message .
-.Pp
-.Fl W
-Waits until
-.Ar shell\-command
-exits, then returns its exit status.
-For example:
-.Bd -literal -offset indent
-$ tmux new-pane -W 'vi afile'
-$ echo $?
-0
-.Ed
-.Pp
-.Fl E ,
-or an empty
-.Ar shell\-command ,
-(\[aq]\[aq]) will create an empty pane with no command running in it;
-.Ic display-message
-.Fl I
-can write to an empty pane.
-The
-.Fl I
-flag will create an empty pane and forward any output from stdin to it.
-For example:
-.Bd -literal -offset indent
-$ make 2>&1|tmux new\-pane \-dI &
-.Ed
+.Fl L
+option makes
+.Ic new\-pane
+behave like
+.Ic split\-window .
 .Pp
 All other options have the same meaning as for the
-.Ic new\-window
+.Ic split\-window
 command.
 .Tg nextl
 .It Ic next\-layout Op Fl t Ar target\-window
@@ -4048,14 +4005,92 @@ the command behaves like
 .Op Ar shell\-command Op Ar argument ...
 .Xc
 .D1 Pq alias: Ic splitw
-Creates a new pane by splitting
+Create a new pane by splitting
 .Ar target\-pane .
-Shares behavior with
-.Ic new\-pane .
+If
+.Fl d
+is given, the session does not make the new pane the current pane.
+.Fl Z
+zooms if the window is not zoomed, or keeps it zoomed if already zoomed.
+.Fl s
+sets the style for the pane content.
+.Fl S
+sets the border style when the pane is active and
+.Fl R
+sets the border style when the pane is inactive (see
+.Sx STYLES ) .
+.Fl T
+sets the pane title.
+.Pp
+.Fl h
+does a horizontal split and
+.Fl v
+a vertical split; if neither is specified,
+.Fl v
+is assumed.
+The
+.Fl l
+option specifies the size of the new pane in lines (for vertical split) or in
+columns (for horizontal split);
+.Ar size
+may be followed by
+.Ql %
+to specify a percentage of the available space.
+.Fl p
+is a shorthand option for this.
+The
+.Fl b
+option causes the new pane to be created to the left of or above
+.Ar target\-pane .
+The
+.Fl f
+option creates a new pane spanning the full window height (with
+.Fl h )
+or full window width (with
+.Fl v ) ,
+instead of splitting the active pane.
+.Pp
+.Fl k
+keeps the pane open after the optional
+.Ar shell\-command
+exits and waits for a key to be pressed before closing it.
+The message shown is controlled by the
+.Ic remain\-on\-exit\-format
+option.
+.Fl m Ar message
+is equivalent to
+.Fl k
+but also sets the
+.Ic remain\-on\-exit\-format
+option for this pane to
+.Ar message .
+.Pp
+.Fl W
+Waits until
+.Ar shell\-command
+exits, then returns its exit status.
+For example:
+.Bd -literal -offset indent
+$ tmux new-pane -W 'vi afile'
+$ echo $?
+0
+.Ed
+.Pp
+.Fl E ,
+or an empty
+.Ar shell\-command ,
+(\[aq]\[aq]) will create an empty pane with no command running in it;
+.Ic display-message
+.Fl I
+can write to an empty pane.
+The
+.Fl I
+flag will create an empty pane and forward any output from stdin to it.
+For example:
+.Bd -literal -offset indent
+$ make 2>&1|tmux new\-pane \-dI &
+.Ed
 .Pp
-See
-.Ic new\-pane
-for more details.
 .Tg swapp
 .It Xo Ic swap\-pane
 .Op Fl dDUZ

From e0dd40f812fdbc9a8f7dfa2810d8db3666ce1c66 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sat, 27 Jun 2026 12:27:43 +0000
Subject: [PATCH 06/14] Clear lines before writing in copy mode to avoid
 leaving stray text when new line is shorter than old.

---
 window-copy.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/window-copy.c b/window-copy.c
index 4ba791e75..0a37c5e9d 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -5154,6 +5154,9 @@ window_copy_write_line(struct window_mode_entry *wme,
 	else
 		content_sx = sx;
 
+	screen_write_cursormove(ctx, 0, py, 0);
+	screen_write_clearline(ctx, 8);
+
 	ft = format_create_defaults(NULL, NULL, NULL, NULL, wp);
 
 	style_apply(&gc, oo, "copy-mode-position-style", ft);

From 7cd33ce0dd3d3e8afe50815a237ad14457d343fc Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sat, 27 Jun 2026 12:37:36 +0000
Subject: [PATCH 07/14] Set view name immediately when entering mode.

---
 window-tree.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/window-tree.c b/window-tree.c
index 19bd5569f..c37082c91 100644
--- a/window-tree.c
+++ b/window-tree.c
@@ -1138,6 +1138,7 @@ window_tree_init(struct window_mode_entry *wme, struct cmd_find_state *fs,
 	    window_tree_get_key, window_tree_swap, window_tree_sort,
 	    window_tree_help, data, window_tree_menu_items, &s);
 	mode_tree_zoom(data->data, args);
+	mode_tree_view_name(data->data, "preview");
 
 	mode_tree_build(data->data);
 	mode_tree_draw(data->data);

From b0db912bde8f77eefa112e00385e6fee8fdbd447 Mon Sep 17 00:00:00 2001
From: Your Name <you@example.com>
Date: Sun, 28 Jun 2026 16:52:28 +0100
Subject: [PATCH 08/14] Update check-names test.

---
 regress/check-names.sh | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/regress/check-names.sh b/regress/check-names.sh
index 104ff01b8..21e185ac1 100644
--- a/regress/check-names.sh
+++ b/regress/check-names.sh
@@ -110,20 +110,26 @@ must_fail $TMUX set-buffer -b "bad${invalid}name" data
 # Titles set by commands allow '#', ':' and '.'.
 $TMUX select-pane -T 'title#:.ok' || fail "command title rejected"
 must_equal "$($TMUX display-message -p '#{pane_title}')" 'title#:.ok'
+$TMUX send-keys "printf '\\033]2;title#[fg=red]ok\\007'" Enter || exit 1
+sleep 1
+must_equal "$($TMUX display-message -p '#{pane_title}')" 'title#[fg=red]ok'
+$TMUX send-keys "printf '\\033]2;title#(bad)\\007'" Enter || exit 1
+sleep 1
+must_equal "$($TMUX display-message -p '#{pane_title}')" 'title_(bad)'
 
 # Buffer names allow '#', ':' and '.'.
 $TMUX set-buffer -b 'buffer#:.ok' data || fail "buffer name rejected"
 must_equal "$($TMUX list-buffers -F '#{buffer_name}')" 'buffer#:.ok'
 
-# Window names from escape sequences reject '#', ':' and '.' by cleaning them.
+# Window names from escape sequences allow '#' except in '#('.
 $TMUX send-keys "printf '\\033kescape#:.ok\\033\\\\'" Enter || exit 1
 sleep 1
-must_equal "$($TMUX display-message -p '#{window_name}')" 'escape___ok'
+must_equal "$($TMUX display-message -p '#{window_name}')" 'escape#__ok'
 
 # Titles from escape sequences reject only '#'.
 $TMUX send-keys "printf '\\033]2;escape#:.ok\\007'" Enter || exit 1
 sleep 1
-must_equal "$($TMUX display-message -p '#{pane_title}')" 'escape_:.ok'
+must_equal "$($TMUX display-message -p '#{pane_title}')" 'escape#:.ok'
 
 # Invalid UTF-8 from escape sequences is ignored.
 $TMUX rename-window 'before-invalid' || exit 1

From 96899dc527999ee9130246eec86d76d79b1a8d97 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sun, 28 Jun 2026 15:53:18 +0000
Subject: [PATCH 09/14] Only forbid #( in names and titles (styles are #[ and
 are useful).

---
 tmux.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tmux.c b/tmux.c
index bc018da88..7236360bb 100644
--- a/tmux.c
+++ b/tmux.c
@@ -295,7 +295,10 @@ clean_name(const char *name, const char* forbid)
 		return (NULL);
 	copy = xstrdup(name);
 	for (cp = copy; *cp != '\0'; cp++) {
-		if (strchr(forbid, *cp) != NULL)
+		if (*cp == '#' && strchr(forbid, '#') != NULL) {
+			if (cp[1] == '(')
+				*cp = '_';
+		} else if (strchr(forbid, *cp) != NULL)
 			*cp = '_';
 	}
 	utf8_stravis(&new_name, copy, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);

From 2dc704abb6f6b72e3a5d452c821e53084ddcae2c Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Sun, 28 Jun 2026 17:01:52 +0100
Subject: [PATCH 10/14] Always set SIXEL aspect ratio to 1:1, GitHub issue 5291
 from James Holderness.

---
 image-sixel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/image-sixel.c b/image-sixel.c
index 2e6f247d2..a004d78f8 100644
--- a/image-sixel.c
+++ b/image-sixel.c
@@ -586,7 +586,7 @@ sixel_print(struct sixel_image *si, struct sixel_image *map, size_t *size)
 	len = 8192;
 	buf = xmalloc(len);
 
-	tmplen = xsnprintf(tmp, sizeof tmp, "\033P0;%uq", si->p2);
+	tmplen = xsnprintf(tmp, sizeof tmp, "\033P9;%uq", si->p2);
 	sixel_print_add(&buf, &len, &used, tmp, tmplen);
 
 	if (si->set_ra) {

From c29b41e5279f246669aae32f0c15c20cfa82c3c6 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Mon, 29 Jun 2026 07:45:09 +0000
Subject: [PATCH 11/14] Make pane scrollbars able to auto-hide after a short
 timeout. This replaces the previous "modal" behaviour where the pane would be
 resized, which tended to make a mess. Instead, the scrollbar appears when
 scrolling or when hovered over with the mouse and disappears a (configurable)
 short period later. From Michael Grant.

---
 cmd-resize-pane.c |   4 +-
 layout.c          |   6 +--
 options-table.c   |  14 ++++-
 options.c         |   5 ++
 regsub.c          |   3 +-
 screen-redraw.c   |  41 ++++++++++----
 screen-write.c    |   6 ++-
 server-client.c   | 123 +++++++++++++++++++++++++++++++++++++++---
 sort.c            |   4 +-
 tmux.1            |  35 ++++++++----
 tmux.h            |  12 +++++
 window-copy.c     |  44 +++++++++++----
 window-visible.c  |   2 +-
 window.c          | 133 +++++++++++++++++++++++++++++++++++++++++++++-
 14 files changed, 379 insertions(+), 53 deletions(-)

diff --git a/cmd-resize-pane.c b/cmd-resize-pane.c
index 734280af1..185844f2e 100644
--- a/cmd-resize-pane.c
+++ b/cmd-resize-pane.c
@@ -251,10 +251,10 @@ cmd_resize_pane_mouse_resize_move_floating(struct client *c,
 	sb_pos = options_get_number(w->options, "pane-scrollbars-position");
 	left = wp->xoff - 1;
 	right = wp->xoff + sx;
-	if (window_pane_show_scrollbar(wp, scrollbars) &&
+	if (window_pane_scrollbar_reserve(wp, scrollbars) &&
 	    sb_pos == PANE_SCROLLBARS_LEFT) {
 		left -= wp->scrollbar_style.width + wp->scrollbar_style.pad;
-	} else if (window_pane_show_scrollbar(wp, scrollbars) &&
+	} else if (window_pane_scrollbar_reserve(wp, scrollbars) &&
 	    sb_pos == PANE_SCROLLBARS_RIGHT) {
 		right += wp->scrollbar_style.width + wp->scrollbar_style.pad;
 	}
diff --git a/layout.c b/layout.c
index 279f504af..a65cd9d86 100644
--- a/layout.c
+++ b/layout.c
@@ -462,7 +462,7 @@ layout_fix_panes(struct window *w, struct window_pane *skip)
 			sy--;
 		}
 
-		if (window_pane_show_scrollbar(wp, scrollbars)) {
+		if (window_pane_scrollbar_reserve(wp, scrollbars)) {
 			sb_w = wp->scrollbar_style.width;
 			sb_pad = wp->scrollbar_style.pad;
 			if (sb_w < 1)
@@ -535,7 +535,7 @@ layout_resize_check(struct window *w, struct layout_cell *lc,
 		/* Space available in this cell only. */
 		if (type == LAYOUT_LEFTRIGHT) {
 			available = lc->sx;
-			if (scrollbars)
+			if (scrollbars == PANE_SCROLLBARS_ALWAYS)
 				minimum = PANE_MINIMUM + sb_style->width +
 				    sb_style->pad;
 			else
@@ -1263,7 +1263,7 @@ layout_split_check_space(struct window_pane *wp, struct layout_cell *lc,
 
 	switch (type) {
 	case LAYOUT_LEFTRIGHT:
-		if (scrollbars) {
+		if (scrollbars == PANE_SCROLLBARS_ALWAYS) {
 			minimum = PANE_MINIMUM * 2 + sb_style->width +
 			    sb_style->pad;
 		} else
diff --git a/options-table.c b/options-table.c
index ddd8b4634..5019bb244 100644
--- a/options-table.c
+++ b/options-table.c
@@ -65,7 +65,7 @@ static const char *options_table_cursor_style_list[] = {
 	"blinking-bar", "bar", NULL
 };
 static const char *options_table_pane_scrollbars_list[] = {
-	"off", "modal", "on", NULL
+	"off", "modal", "on", "auto-hide", NULL
 };
 static const char *options_table_pane_scrollbars_position_list[] = {
 	"right", "left", NULL
@@ -1595,7 +1595,17 @@ const struct options_table_entry options_table[] = {
 	  .scope = OPTIONS_TABLE_WINDOW,
 	  .choices = options_table_pane_scrollbars_list,
 	  .default_num = PANE_SCROLLBARS_OFF,
-	  .text = "Pane scrollbar state."
+	  .text = "Pane scrollbar state: off, on, modal, or auto-hide."
+	},
+
+	{ .name = "pane-scrollbars-timeout",
+	  .type = OPTIONS_TABLE_NUMBER,
+	  .scope = OPTIONS_TABLE_WINDOW,
+	  .minimum = 0,
+	  .maximum = INT_MAX,
+	  .default_num = 500,
+	  .unit = "milliseconds",
+	  .text = "Time before modal and auto-hide pane scrollbars disappear."
 	},
 
 	{ .name = "pane-scrollbars-style",
diff --git a/options.c b/options.c
index db0f221a3..e05930463 100644
--- a/options.c
+++ b/options.c
@@ -1264,6 +1264,7 @@ options_push_changes(const char *name)
 	    strcmp(name, "pane-border-lines") == 0 ||
 	    strcmp(name, "pane-border-status") == 0 ||
 	    strcmp(name, "pane-scrollbars") == 0 ||
+	    strcmp(name, "pane-scrollbars-timeout") == 0 ||
 	    strcmp(name, "pane-scrollbars-position") == 0 ||
 	    strcmp(name, "pane-scrollbars-style") == 0)
 		redraw_invalidate_all_scenes();
@@ -1288,6 +1289,10 @@ options_push_changes(const char *name)
 		RB_FOREACH(w, windows, &windows)
 			layout_fix_panes(w, NULL);
 	}
+	if (strcmp(name, "pane-scrollbars") == 0) {
+		RB_FOREACH(wp, window_pane_tree, &all_window_panes)
+			window_pane_scrollbar_hide(wp);
+	}
 	if (strcmp(name, "pane-scrollbars-style") == 0) {
 		RB_FOREACH(wp, window_pane_tree, &all_window_panes) {
 			style_set_scrollbar_style_from_option(
diff --git a/regsub.c b/regsub.c
index a863f9fd8..62d750d8a 100644
--- a/regsub.c
+++ b/regsub.c
@@ -24,7 +24,8 @@
 #include "tmux.h"
 
 static void
-regsub_copy(char **buf, ssize_t *len, const char *text, size_t start, size_t end)
+regsub_copy(char **buf, ssize_t *len, const char *text, size_t start,
+    size_t end)
 {
 	size_t	add = end - start;
 
diff --git a/screen-redraw.c b/screen-redraw.c
index e8dd8ec0f..813d4e563 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -81,6 +81,7 @@ enum redraw_span_type {
 #define REDRAW_BORDER_IS_ARROW 0x1
 #define REDRAW_SCROLLBAR_LEFT 0x2
 #define REDRAW_SCROLLBAR_RIGHT 0x4
+#define REDRAW_SCROLLBAR_OVERLAY 0x8
 
 /* Draw operations. */
 #define REDRAW_PANE 0x1
@@ -447,7 +448,7 @@ redraw_mark_pane_inside(struct redraw_build_ctx *bctx, struct window_pane *wp)
 /* Mark scrollbar data. */
 static void
 redraw_mark_pane_scrollbar(struct redraw_build_ctx *bctx,
-    struct window_pane *wp, int sb_w, int sb_left)
+    struct window_pane *wp, int sb_w, int sb_left, int overlay)
 {
 	struct redraw_build_cell	*bc;
 	u_int				 x, y;
@@ -457,7 +458,13 @@ redraw_mark_pane_scrollbar(struct redraw_build_ctx *bctx,
 	if (sb_w == 0)
 		return;
 
-	if (sb_left) {
+	if (overlay && sb_left) {
+		sx = wp->xoff;
+		ex = sx + sb_w - 1;
+	} else if (overlay) {
+		ex = wp->xoff + (int)wp->sx - 1;
+		sx = ex - sb_w + 1;
+	} else if (sb_left) {
 		sx = wp->xoff - sb_w;
 		ex = wp->xoff - 1;
 	} else {
@@ -481,6 +488,8 @@ redraw_mark_pane_scrollbar(struct redraw_build_ctx *bctx,
 				bc->data.sb.flags |= REDRAW_SCROLLBAR_LEFT;
 			else
 				bc->data.sb.flags |= REDRAW_SCROLLBAR_RIGHT;
+			if (overlay)
+				bc->data.sb.flags |= REDRAW_SCROLLBAR_OVERLAY;
 		}
 	}
 }
@@ -755,19 +764,30 @@ redraw_mark_pane_borders(struct redraw_build_ctx *bctx, struct window_pane *wp,
 static void
 redraw_mark_pane(struct redraw_build_ctx *bctx, struct window_pane *wp)
 {
-	int	sb_w = 0, sb_left = 0;
+	int	sb_w = 0, sb_left = 0, overlay = 0;
 
 	if (!window_pane_is_visible(wp))
 		return;
 
-	if (window_pane_show_scrollbar(wp, bctx->sb))
-		sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
+	if (window_pane_scrollbar_visible(wp, bctx->sb)) {
+		overlay = window_pane_scrollbar_overlay(wp, bctx->sb);
+		if (overlay) {
+			sb_w = wp->scrollbar_style.width +
+			    wp->scrollbar_style.pad;
+			if (sb_w > (int)wp->sx) {
+				sb_w = wp->scrollbar_style.width;
+				if (sb_w > (int)wp->sx)
+					sb_w = wp->sx;
+			}
+		} else
+			sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
+	}
 	if (sb_w != 0 && bctx->sbp == PANE_SCROLLBARS_LEFT)
 		sb_left = 1;
 
 	redraw_mark_pane_inside(bctx, wp);
-	redraw_mark_pane_borders(bctx, wp, sb_w, sb_left);
-	redraw_mark_pane_scrollbar(bctx, wp, sb_w, sb_left);
+	redraw_mark_pane_borders(bctx, wp, overlay ? 0 : sb_w, sb_left);
+	redraw_mark_pane_scrollbar(bctx, wp, sb_w, sb_left, overlay);
 }
 
 /* Choose the pane that will provide the border style for two-pane layouts. */
@@ -1220,7 +1240,7 @@ redraw_draw_scrollbar_span(struct redraw_draw_ctx *dctx,
 	struct screen		*s = wp->screen;
 	struct tty		*tty = &scene->c->tty;
 	struct style		*sb_style = &wp->scrollbar_style;
-	struct grid_cell	 gc, slgc, *gcp;
+	struct grid_cell	 gc, slgc, pad_gc, *gcp;
 	double			 pct_view;
 	u_int			 total_height, slider_h, slider_y;
 	u_int			 sb_h = span->data.sb.height;
@@ -1260,6 +1280,7 @@ redraw_draw_scrollbar_span(struct redraw_draw_ctx *dctx,
 	memcpy(&slgc, &gc, sizeof slgc);
 	slgc.fg = gc.bg;
 	slgc.bg = gc.fg;
+	tty_default_colours(&pad_gc, wp, NULL);
 
 	sb_w = sb_style->width;
 	sb_pad = sb_style->pad;
@@ -1269,12 +1290,12 @@ redraw_draw_scrollbar_span(struct redraw_draw_ctx *dctx,
 	for (i = 0; i < n; i++) {
 		if (span->data.sb.flags & REDRAW_SCROLLBAR_LEFT) {
 			if (off + i >= sb_w && off + i < sb_w + sb_pad) {
-				tty_cell(tty, &grid_default_cell, NULL);
+				tty_cell(tty, &pad_gc, NULL);
 				continue;
 			}
 		} else {
 			if (off + i < sb_pad) {
-				tty_cell(tty, &grid_default_cell, NULL);
+				tty_cell(tty, &pad_gc, NULL);
 				continue;
 			}
 		}
diff --git a/screen-write.c b/screen-write.c
index ba7ffd930..31d177ef0 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -2096,6 +2096,10 @@ screen_write_collect_flush_scrolled(struct screen_write_ctx *ctx)
 		screen_write_redraw_pane(ctx, &ttyctx);
 		return 0;
 	}
+	if (wp != NULL && window_pane_scrollbar_overlay_visible(wp)) {
+		wp->flags |= PANE_REDRAW;
+		return 0;
+	}
 
 	log_debug("%s: scrolled %u (region %u-%u)", __func__, ctx->scrolled,
 	    s->rupper, s->rlower);
@@ -2109,7 +2113,7 @@ screen_write_collect_flush_scrolled(struct screen_write_ctx *ctx)
 	tty_write(tty_cmd_scrollup, &ttyctx);
 
 	if (wp != NULL)
-		wp->flags |= PANE_REDRAWSCROLLBAR;
+		window_pane_scrollbar_redraw(wp);
 	return 1;
 }
 
diff --git a/server-client.c b/server-client.c
index 5b2651658..43bf7600d 100644
--- a/server-client.c
+++ b/server-client.c
@@ -52,6 +52,8 @@ static void	server_client_dispatch(struct imsg *, void *);
 static int	server_client_dispatch_command(struct client *, struct imsg *);
 static int	server_client_dispatch_identify(struct client *, struct imsg *);
 static int	server_client_dispatch_shell(struct client *);
+static void	server_client_update_scrollbar_hover(struct client *, int, int,
+		    int);
 static void	server_client_report_theme(struct client *, enum client_theme);
 
 /* Compare client windows. */
@@ -605,6 +607,60 @@ server_client_exec(struct client *c, const char *cmd)
 	free(msg);
 }
 
+/* Is this point inside the auto-hide scrollbar interaction area? */
+static int
+server_client_in_scrollbar_area(struct window_pane *wp, int px, int py)
+{
+	struct window	*w = wp->window;
+	u_int		 width, pad, total;
+	int		 sb, sb_pos, start, end;
+
+	sb = options_get_number(w->options, "pane-scrollbars");
+	if (!window_pane_scrollbar_overlay(wp, sb))
+		return (0);
+	if (py < wp->yoff || py >= wp->yoff + (int)wp->sy)
+		return (0);
+
+	width = wp->scrollbar_style.width;
+	pad = wp->scrollbar_style.pad;
+	total = width + pad;
+	if (total == 0 || total > wp->sx)
+		total = wp->sx;
+
+	sb_pos = options_get_number(w->options, "pane-scrollbars-position");
+	if (sb_pos == PANE_SCROLLBARS_LEFT) {
+		start = wp->xoff;
+		end = wp->xoff + (int)total - 1;
+	} else {
+		end = wp->xoff + (int)wp->sx - 1;
+		start = end - (int)total + 1;
+	}
+	return (px >= start && px <= end);
+}
+
+/* Update auto-hide scrollbars for a mouse movement. */
+static void
+server_client_update_scrollbar_hover(struct client *c, int type, int px, int py)
+{
+	struct window		*w = c->session->curw->window;
+	struct window_pane	*wp;
+
+	if (type != KEYC_TYPE_MOUSEMOVE)
+		return;
+
+	TAILQ_FOREACH(wp, &w->panes, entry) {
+		if (!window_pane_is_visible(wp))
+			continue;
+		if (server_client_in_scrollbar_area(wp, px, py)) {
+			wp->sb_auto_hover = 1;
+			window_pane_scrollbar_show(wp, 1);
+		} else {
+			wp->sb_auto_hover = 0;
+			window_pane_scrollbar_start_timer(wp);
+		}
+	}
+}
+
 /* Is the mouse inside a pane? */
 static enum key_code_mouse_location
 server_client_check_mouse_in_pane(struct window_pane *wp, int px, int py,
@@ -615,14 +671,18 @@ server_client_check_mouse_in_pane(struct window_pane *wp, int px, int py,
 	int			 pane_status, sb, sb_pos, sb_w, sb_pad;
 	int			 pane_status_line, sl_top, sl_bottom;
 	int			 bdr_bottom, bdr_top, bdr_left, bdr_right;
+	int			 sb_start, sb_end, sb_overlay;
 
 	sb = options_get_number(w->options, "pane-scrollbars");
 	sb_pos = options_get_number(w->options, "pane-scrollbars-position");
 	pane_status = window_pane_get_pane_status(wp);
+	sb_overlay = window_pane_scrollbar_overlay(wp, sb);
 
-	if (window_pane_show_scrollbar(wp, sb)) {
+	if (window_pane_scrollbar_visible(wp, sb)) {
 		sb_w = wp->scrollbar_style.width;
 		sb_pad = wp->scrollbar_style.pad;
+		if (sb_overlay && sb_w > (int)wp->sx)
+			sb_w = wp->sx;
 	} else {
 		sb_w = 0;
 		sb_pad = 0;
@@ -635,9 +695,34 @@ server_client_check_mouse_in_pane(struct window_pane *wp, int px, int py,
 	else
 		pane_status_line = -1; /* not used */
 	bdr_left = wp->xoff - 1;
-	if (sb_pos == PANE_SCROLLBARS_LEFT)
+	if (!sb_overlay && sb_pos == PANE_SCROLLBARS_LEFT)
 		bdr_left -= sb_pad + sb_w;
 
+	if (sb_overlay && sb_w != 0 &&
+	    py >= wp->yoff && py < wp->yoff + (int)wp->sy &&
+	    px >= wp->xoff && px < wp->xoff + (int)wp->sx) {
+		if (sb_pos == PANE_SCROLLBARS_LEFT) {
+			sb_start = wp->xoff;
+			sb_end = sb_start + sb_w - 1;
+		} else {
+			sb_end = wp->xoff + (int)wp->sx - 1;
+			sb_start = sb_end - sb_w + 1;
+		}
+		if (px >= sb_start && px <= sb_end) {
+			sl_top = wp->yoff + wp->sb_slider_y;
+			sl_bottom = (wp->yoff + wp->sb_slider_y +
+			    wp->sb_slider_h - 1);
+			if (py < sl_top)
+				return (KEYC_MOUSE_LOCATION_SCROLLBAR_UP);
+			else if (py >= sl_top && py <= sl_bottom) {
+				*sl_mpos = (py - wp->sb_slider_y - wp->yoff);
+				return (KEYC_MOUSE_LOCATION_SCROLLBAR_SLIDER);
+			} else
+				return (KEYC_MOUSE_LOCATION_SCROLLBAR_DOWN);
+		}
+		return (KEYC_MOUSE_LOCATION_PANE);
+	}
+
 	/* Check if point is within the pane or scrollbar. */
 	if (((pane_status != PANE_STATUS_OFF &&
 	    py != pane_status_line && py != wp->yoff + (int)wp->sy) ||
@@ -685,7 +770,7 @@ server_client_check_mouse_in_pane(struct window_pane *wp, int px, int py,
 			if (window_pane_is_floating(fwp) &&
 			    window_pane_get_pane_lines(fwp) == PANE_LINES_NONE)
 				continue;
-			if (window_pane_show_scrollbar(fwp, sb)) {
+			if (window_pane_scrollbar_reserve(fwp, sb)) {
 				sb_w = fwp->scrollbar_style.width;
 				sb_pad = fwp->scrollbar_style.pad;
 			} else {
@@ -915,10 +1000,14 @@ have_event:
 			tty_window_offset(&c->tty, &m->ox, &m->oy, &sx, &sy);
 			log_debug("mouse window @%u at %u,%u (%ux%u)",
 				  w->id, m->ox, m->oy, sx, sy);
-			if (px > sx || py > sy)
+			if (px > sx || py > sy) {
+				server_client_update_scrollbar_hover(c, type,
+				    -1, -1);
 				return (KEYC_UNKNOWN);
+			}
 			px = px + m->ox;
 			py = py + m->oy;
+			server_client_update_scrollbar_hover(c, type, px, py);
 
 			if (type == KEYC_TYPE_MOUSEDRAG && lwp != NULL) {
 				/* Use pane from last mouse event. */
@@ -951,7 +1040,8 @@ have_event:
 			m->wp = wp->id;
 			m->w = wp->window->id;
 		}
-	}
+	} else
+		server_client_update_scrollbar_hover(c, type, -1, -1);
 
 	/* Reset click type or add a click timer if needed. */
 	if (type == KEYC_TYPE_MOUSEDOWN ||
@@ -1911,8 +2001,9 @@ server_client_reset_state(struct client *c)
 	struct window_pane	*wp = server_client_get_pane(c), *loop;
 	struct screen		*s = NULL;
 	struct options		*oo = c->session->options;
-	int			 mode = 0, cursor, flags, pane_mode = 0;
+	int			 mode = 0, cursor, flags, pane_mode = 0, sb;
 	u_int			 cx = 0, cy = 0, ox, oy, sx, sy, prompt = 0;
+	u_int			 sb_w;
 	struct visible_ranges	*r;
 
 	if (c->flags & (CLIENT_CONTROL|CLIENT_SUSPENDED))
@@ -1965,6 +2056,21 @@ server_client_reset_state(struct client *c)
 				if (!window_position_is_visible(r, cx))
 					cursor = 0;
 
+			if (window_pane_scrollbar_overlay_visible(wp)) {
+				sb_w = wp->scrollbar_style.width;
+				if (sb_w > wp->sx)
+					sb_w = wp->sx;
+				if (sb_w != 0 &&
+				    options_get_number(w->options,
+				    "pane-scrollbars-position") ==
+				    PANE_SCROLLBARS_LEFT) {
+					if (s->cx < sb_w)
+						cursor = 0;
+				} else if (sb_w != 0 &&
+				    s->cx >= wp->sx - sb_w)
+					cursor = 0;
+			}
+
 				if (status_at_line(c) == 0)
 					cy += status_line_size(c);
 			}
@@ -1992,7 +2098,10 @@ server_client_reset_state(struct client *c)
 					mode |= MODE_MOUSE_ALL;
 			}
 		}
-		if (options_get_number(oo, "focus-follows-mouse"))
+		sb = options_get_number(w->options, "pane-scrollbars");
+		if (options_get_number(oo, "focus-follows-mouse") ||
+		    sb == PANE_SCROLLBARS_MODAL ||
+		    sb == PANE_SCROLLBARS_AUTOHIDE)
 			mode |= MODE_MOUSE_ALL;
 		else if (~mode & MODE_MOUSE_ALL)
 			mode |= MODE_MOUSE_BUTTON;
diff --git a/sort.c b/sort.c
index 212da22ea..c416b8425 100644
--- a/sort.c
+++ b/sort.c
@@ -26,8 +26,8 @@
 static struct sort_criteria *sort_criteria;
 
 static void
-sort_qsort(void *l, u_int len, u_int size, int (*cmp)(const void *, const void *),
-    struct sort_criteria *sort_crit)
+sort_qsort(void *l, u_int len, u_int size, int (*cmp)(const void *,
+    const void *), struct sort_criteria *sort_crit)
 {
 	u_int	 i;
 	void	*tmp, **ll;
diff --git a/tmux.1 b/tmux.1
index 63809bac1..8f74205f8 100644
--- a/tmux.1
+++ b/tmux.1
@@ -5893,7 +5893,7 @@ and
 will fall back to standard ACS line drawing when UTF\-8 is not supported.
 .Pp
 .It Xo Ic pane\-scrollbars
-.Op Ic off | modal | on
+.Op Ic off | modal | on | auto\-hide
 .Xc
 When enabled, a character based scrollbar appears on the left or right
 of each pane.
@@ -5903,19 +5903,29 @@ represents the position and size of the visible part of the pane content.
 .Pp
 If set to
 .Ic on
-the scrollbar is visible all the time.
+the scrollbar is visible all the time and the pane is narrowed by the width of
+the scrollbar.
 If set to
 .Ic modal
-the scrollbar only appears when the pane is in copy mode or view mode.
-When the scrollbar is visible, the pane is narrowed by the width of the
-scrollbar and the text in the pane is reflowed.
+the scrollbar only appears when the pane is in copy mode or view mode and
+auto-hides when not in use.
 If set to
-.Ic modal ,
-the pane is narrowed only when the scrollbar is visible.
+.Ic auto\-hide
+the scrollbar is available all the time but auto-hides when not in use.
+With
+.Ic modal
+and
+.Ic auto\-hide ,
+the scrollbar overlays the pane and does not narrow or reflow the pane.
 .Pp
 See also
 .Ic pane\-scrollbars\-style .
 .Pp
+.It Xo Ic pane\-scrollbars\-position
+.Op Ic left | right
+.Xc
+Sets which side of the pane to display pane scrollbars on.
+.Pp
 .It Ic pane\-scrollbars\-style Ar style
 Set the scrollbars style.
 For how to specify
@@ -5932,10 +5942,13 @@ attribute sets the width of the scrollbar and the
 attribute the padding between the scrollbar and the pane.
 Other attributes are ignored.
 .Pp
-.It Xo Ic pane\-scrollbars\-position
-.Op Ic left | right
-.Xc
-Sets which side of the pane to display pane scrollbars on.
+.It Ic pane\-scrollbars\-timeout Ar time
+Set the time in milliseconds before scrollbars are hidden when
+.Ic pane\-scrollbars
+is
+.Ic modal
+or
+.Ic auto\-hide .
 .Pp
 .It Ic pane\-status\-current\-style Ar style
 Set status line style for the currently active pane.
diff --git a/tmux.h b/tmux.h
index 869936e68..f34b3b324 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1266,6 +1266,9 @@ struct window_pane {
 
 	u_int		 sb_slider_y;
 	u_int		 sb_slider_h;
+	int		 sb_auto_visible;
+	int		 sb_auto_hover;
+	struct event	 sb_auto_timer;
 
 	int		 argc;
 	char	       **argv;
@@ -1440,6 +1443,7 @@ TAILQ_HEAD(winlink_stack, winlink);
 #define PANE_SCROLLBARS_OFF 0
 #define PANE_SCROLLBARS_MODAL 1
 #define PANE_SCROLLBARS_ALWAYS 2
+#define PANE_SCROLLBARS_AUTOHIDE 3
 
 /* Pane scrollbars position option. */
 #define PANE_SCROLLBARS_RIGHT 0
@@ -3581,6 +3585,14 @@ void		 window_set_fill_character(struct window *);
 void		 window_pane_default_cursor(struct window_pane *);
 int		 window_pane_mode(struct window_pane *);
 int		 window_pane_show_scrollbar(struct window_pane *, int);
+int		 window_pane_scrollbar_reserve(struct window_pane *, int);
+int		 window_pane_scrollbar_visible(struct window_pane *, int);
+int		 window_pane_scrollbar_overlay(struct window_pane *, int);
+int		 window_pane_scrollbar_overlay_visible(struct window_pane *);
+void		 window_pane_scrollbar_show(struct window_pane *, int);
+void		 window_pane_scrollbar_hide(struct window_pane *);
+void		 window_pane_scrollbar_start_timer(struct window_pane *);
+void		 window_pane_scrollbar_redraw(struct window_pane *);
 int		 window_pane_get_bg(struct window_pane *);
 int		 window_pane_get_fg(struct window_pane *);
 int		 window_pane_get_fg_control_client(struct window_pane *);
diff --git a/window-copy.c b/window-copy.c
index 0a37c5e9d..aedbba99b 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -61,8 +61,10 @@ static int	window_copy_line_number_mode(struct window_mode_entry *);
 static int	window_copy_line_number_is_absolute(struct window_mode_entry *);
 static int	window_copy_line_numbers_active(struct window_mode_entry *);
 static u_int	window_copy_line_number_width(struct window_mode_entry *);
-static u_int	window_copy_cursor_offset(struct window_mode_entry *, u_int, u_int);
-static u_int	window_copy_cursor_unoffset(struct window_mode_entry *, u_int, u_int);
+static u_int	window_copy_cursor_offset(struct window_mode_entry *, u_int,
+		    u_int);
+static u_int	window_copy_cursor_unoffset(struct window_mode_entry *, u_int,
+		    u_int);
 static void	window_copy_write_line(struct window_mode_entry *,
 		    struct screen_write_ctx *, u_int);
 static void	window_copy_write_lines(struct window_mode_entry *,
@@ -860,6 +862,7 @@ window_copy_scroll1(struct window_mode_entry *wme, struct window_pane *wp,
 	if (data->searchmark != NULL && !data->timeout)
 		window_copy_search_marks(wme, NULL, data->searchregex, 1);
 	window_copy_update_selection(wme, 1, 0);
+	window_pane_scrollbar_show(wp, 1);
 	window_copy_redraw_screen(wme);
 }
 
@@ -913,6 +916,7 @@ window_copy_pageup1(struct window_mode_entry *wme, int half_page)
 	if (data->searchmark != NULL && !data->timeout)
 		window_copy_search_marks(wme, NULL, data->searchregex, 1);
 	window_copy_update_selection(wme, 1, 0);
+	window_pane_scrollbar_show(wme->wp, 1);
 	window_copy_redraw_screen(wme);
 }
 
@@ -973,6 +977,7 @@ window_copy_pagedown1(struct window_mode_entry *wme, int half_page,
 	if (data->searchmark != NULL && !data->timeout)
 		window_copy_search_marks(wme, NULL, data->searchregex, 1);
 	window_copy_update_selection(wme, 1, 0);
+	window_pane_scrollbar_show(wme->wp, 1);
 	window_copy_redraw_screen(wme);
 	return (0);
 }
@@ -1789,7 +1794,7 @@ window_copy_cmd_history_bottom(struct window_copy_cmd_state *cs)
 	struct window_mode_entry	*wme = cs->wme;
 	struct window_copy_mode_data	*data = wme->data;
 	struct screen			*s = data->backing;
-	u_int				 oy;
+	u_int				 oy, old_oy = data->oy;
 
 	oy = screen_hsize(s) + data->cy - data->oy;
 	if (data->lineflag == LINE_SEL_RIGHT_LEFT && oy == data->endsely)
@@ -1802,6 +1807,8 @@ window_copy_cmd_history_bottom(struct window_copy_cmd_state *cs)
 	if (data->searchmark != NULL && !data->timeout)
 		window_copy_search_marks(wme, NULL, data->searchregex, 1);
 	window_copy_update_selection(wme, 1, 0);
+	if (data->oy != old_oy)
+		window_pane_scrollbar_show(wme->wp, 1);
 	return (WINDOW_COPY_CMD_REDRAW);
 }
 
@@ -1810,7 +1817,7 @@ window_copy_cmd_history_top(struct window_copy_cmd_state *cs)
 {
 	struct window_mode_entry	*wme = cs->wme;
 	struct window_copy_mode_data	*data = wme->data;
-	u_int				 oy;
+	u_int				 oy, old_oy = data->oy;
 
 	oy = screen_hsize(data->backing) + data->cy - data->oy;
 	if (data->lineflag == LINE_SEL_LEFT_RIGHT && oy == data->sely)
@@ -1823,6 +1830,8 @@ window_copy_cmd_history_top(struct window_copy_cmd_state *cs)
 	if (data->searchmark != NULL && !data->timeout)
 		window_copy_search_marks(wme, NULL, data->searchregex, 1);
 	window_copy_update_selection(wme, 1, 0);
+	if (data->oy != old_oy)
+		window_pane_scrollbar_show(wme->wp, 1);
 	return (WINDOW_COPY_CMD_REDRAW);
 }
 
@@ -3772,7 +3781,7 @@ window_copy_scroll_to(struct window_mode_entry *wme, u_int px, u_int py,
 {
 	struct window_copy_mode_data	*data = wme->data;
 	struct grid			*gd = data->backing->grid;
-	u_int				 offset, gap;
+	u_int				 offset, gap, old_oy = data->oy;
 
 	data->cx = px;
 
@@ -3796,6 +3805,8 @@ window_copy_scroll_to(struct window_mode_entry *wme, u_int px, u_int py,
 	if (!no_redraw && data->searchmark != NULL && !data->timeout)
 		window_copy_search_marks(wme, NULL, data->searchregex, 1);
 	window_copy_update_selection(wme, 1, 0);
+	if (data->oy != old_oy)
+		window_pane_scrollbar_show(wme->wp, 1);
 	if (!no_redraw)
 		window_copy_redraw_screen(wme);
 }
@@ -5278,7 +5289,10 @@ window_copy_redraw_lines(struct window_mode_entry *wme, u_int py, u_int ny)
 		return;
 	}
 
-	screen_write_start_pane(&ctx, wp, NULL);
+	if (window_pane_scrollbar_overlay_visible(wp))
+		screen_write_start(&ctx, &data->screen);
+	else
+		screen_write_start_pane(&ctx, wp, NULL);
 	for (i = py; i < py + ny; i++)
 		window_copy_write_line(wme, &ctx, i);
 	screen_write_cursormove(&ctx,
@@ -5286,7 +5300,7 @@ window_copy_redraw_lines(struct window_mode_entry *wme, u_int py, u_int ny)
 	    0);
 	screen_write_stop(&ctx);
 
-	wp->flags |= PANE_REDRAWSCROLLBAR;
+	window_pane_scrollbar_redraw(wp);
 }
 
 static void
@@ -6542,6 +6556,7 @@ window_copy_scroll_up(struct window_mode_entry *wme, u_int ny)
 	if (ny == 0)
 		return;
 	data->oy -= ny;
+	window_pane_scrollbar_show(wp, 1);
 
 	if (data->searchmark != NULL && !data->timeout)
 		window_copy_search_marks(wme, NULL, data->searchregex, 1);
@@ -6573,7 +6588,10 @@ window_copy_scroll_up(struct window_mode_entry *wme, u_int ny)
 		return;
 	}
 
-	screen_write_start_pane(&ctx, wp, NULL);
+	if (window_pane_scrollbar_overlay_visible(wp))
+		screen_write_start(&ctx, &data->screen);
+	else
+		screen_write_start_pane(&ctx, wp, NULL);
 	screen_write_cursormove(&ctx, 0, 0, 0);
 	screen_write_deleteline(&ctx, ny, 8);
 	window_copy_write_lines(wme, &ctx, screen_size_y(s) - ny, ny);
@@ -6588,7 +6606,7 @@ window_copy_scroll_up(struct window_mode_entry *wme, u_int ny)
 	    window_copy_cursor_offset(wme, data->cx, screen_size_x(s)), data->cy,
 	    0);
 	screen_write_stop(&ctx);
-	wp->flags |= PANE_REDRAWSCROLLBAR;
+	window_pane_scrollbar_redraw(wp);
 }
 
 static void
@@ -6607,6 +6625,7 @@ window_copy_scroll_down(struct window_mode_entry *wme, u_int ny)
 	if (ny == 0)
 		return;
 	data->oy += ny;
+	window_pane_scrollbar_show(wp, 1);
 
 	if (data->searchmark != NULL && !data->timeout)
 		window_copy_search_marks(wme, NULL, data->searchregex, 1);
@@ -6633,7 +6652,10 @@ window_copy_scroll_down(struct window_mode_entry *wme, u_int ny)
 		return;
 	}
 
-	screen_write_start_pane(&ctx, wp, NULL);
+	if (window_pane_scrollbar_overlay_visible(wp))
+		screen_write_start(&ctx, &data->screen);
+	else
+		screen_write_start_pane(&ctx, wp, NULL);
 	screen_write_cursormove(&ctx, 0, 0, 0);
 	screen_write_insertline(&ctx, ny, 8);
 	window_copy_write_lines(wme, &ctx, 0, ny);
@@ -6644,7 +6666,7 @@ window_copy_scroll_down(struct window_mode_entry *wme, u_int ny)
 	screen_write_cursormove(&ctx, window_copy_cursor_offset(wme, data->cx,
 	    screen_size_x(s)), data->cy, 0);
 	screen_write_stop(&ctx);
-	wp->flags |= PANE_REDRAWSCROLLBAR;
+	window_pane_scrollbar_redraw(wp);
 }
 
 static void
diff --git a/window-visible.c b/window-visible.c
index f5b034475..7ec7fcfb5 100644
--- a/window-visible.c
+++ b/window-visible.c
@@ -126,7 +126,7 @@ window_visible_ranges(struct window_pane *base_wp, int px, int py, u_int width,
 			continue;
 
 		sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
-		if (!window_pane_show_scrollbar(wp, sb))
+		if (!window_pane_scrollbar_reserve(wp, sb))
 			sb_w = sb_pos = 0;
 
 		for (i = 0; i < r->used; i++) {
diff --git a/window.c b/window.c
index 1965685b6..a3c228039 100644
--- a/window.c
+++ b/window.c
@@ -73,6 +73,7 @@ struct window_pane_input_data {
 static struct window_pane *window_pane_create(struct window *, u_int, u_int,
 		    u_int);
 static void	window_pane_destroy(struct window_pane *);
+static void	window_pane_scrollbar_timer(int, short, void *);
 static void	window_pane_full_size_offset(struct window_pane *wp,
 		    int *xoff, int *yoff, u_int *sx, u_int *sy);
 
@@ -1105,6 +1106,7 @@ window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
 
 	screen_init(&wp->status_screen, 1, 1, 0);
 	style_ranges_init(&wp->border_status_line.ranges);
+	evtimer_set(&wp->sb_auto_timer, window_pane_scrollbar_timer, wp);
 
 	if (gethostname(host, sizeof host) == 0)
 		screen_set_title(&wp->base, host, 0);
@@ -1151,6 +1153,52 @@ window_pane_free_modes(struct window_pane *wp)
 	wp->screen = &wp->base;
 }
 
+static void
+window_pane_scrollbar_timer(__unused int fd, __unused short events, void *arg)
+{
+	struct window_pane	*wp = arg;
+
+	wp->sb_auto_hover = 0;
+	window_pane_scrollbar_hide(wp);
+}
+
+static int
+window_pane_scrollbar_auto_hide(struct window_pane *wp)
+{
+	int	sb;
+
+	sb = options_get_number(wp->window->options, "pane-scrollbars");
+	return (sb == PANE_SCROLLBARS_MODAL || sb == PANE_SCROLLBARS_AUTOHIDE);
+}
+
+int
+window_pane_scrollbar_overlay_visible(struct window_pane *wp)
+{
+	int	sb;
+
+	sb = options_get_number(wp->window->options, "pane-scrollbars");
+	return (window_pane_scrollbar_overlay(wp, sb) &&
+	    window_pane_scrollbar_visible(wp, sb));
+}
+
+void
+window_pane_scrollbar_redraw(struct window_pane *wp)
+{
+	if (window_pane_scrollbar_overlay_visible(wp)) {
+		wp->flags |= PANE_REDRAW;
+		return;
+	}
+	wp->flags |= PANE_REDRAWSCROLLBAR;
+}
+
+static void
+window_pane_scrollbar_redraw_visibility(struct window_pane *wp)
+{
+	redraw_invalidate_scene(wp->window);
+	wp->flags |= PANE_REDRAW;
+	server_redraw_window(wp->window);
+}
+
 static void
 window_pane_destroy(struct window_pane *wp)
 {
@@ -1182,6 +1230,8 @@ window_pane_destroy(struct window_pane *wp)
 		event_del(&wp->resize_timer);
 	if (event_initialized(&wp->sync_timer))
 		event_del(&wp->sync_timer);
+	if (event_initialized(&wp->sb_auto_timer))
+		event_del(&wp->sb_auto_timer);
 	window_pane_clear_resizes(wp, NULL);
 
 	RB_REMOVE(window_pane_tree, &all_window_panes, wp);
@@ -1251,7 +1301,8 @@ window_pane_set_event(struct window_pane *wp)
 }
 
 void
-window_pane_clear_resizes(struct window_pane *wp, struct window_pane_resize *except)
+window_pane_clear_resizes(struct window_pane *wp,
+    struct window_pane_resize *except)
 {
 	struct window_pane_resize	*r, *r1;
 
@@ -1724,7 +1775,7 @@ window_pane_full_size_offset(struct window_pane *wp, int *xoff, int *yoff,
 	pane_scrollbars = options_get_number(w->options, "pane-scrollbars");
 	sb_pos = options_get_number(w->options, "pane-scrollbars-position");
 
-	if (window_pane_show_scrollbar(wp, pane_scrollbars))
+	if (window_pane_scrollbar_reserve(wp, pane_scrollbars))
 		sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
 	else
 		sb_w = 0;
@@ -2151,12 +2202,90 @@ window_pane_show_scrollbar(struct window_pane *wp, int sb_option)
 	if (SCREEN_IS_ALTERNATE(&wp->base))
 		return (0);
 	if (sb_option == PANE_SCROLLBARS_ALWAYS ||
+	    sb_option == PANE_SCROLLBARS_AUTOHIDE ||
 	    (sb_option == PANE_SCROLLBARS_MODAL &&
 	    window_pane_mode(wp) != WINDOW_PANE_NO_MODE))
 		return (1);
 	return (0);
 }
 
+int
+window_pane_scrollbar_reserve(struct window_pane *wp, int sb_option)
+{
+	if (!window_pane_show_scrollbar(wp, sb_option))
+		return (0);
+	return (sb_option == PANE_SCROLLBARS_ALWAYS);
+}
+
+int
+window_pane_scrollbar_overlay(struct window_pane *wp, int sb_option)
+{
+	if (!window_pane_show_scrollbar(wp, sb_option))
+		return (0);
+	return (window_pane_scrollbar_auto_hide(wp));
+}
+
+int
+window_pane_scrollbar_visible(struct window_pane *wp, int sb_option)
+{
+	if (!window_pane_show_scrollbar(wp, sb_option))
+		return (0);
+	if (!window_pane_scrollbar_auto_hide(wp))
+		return (1);
+	return (wp->sb_auto_visible);
+}
+
+void
+window_pane_scrollbar_start_timer(struct window_pane *wp)
+{
+	struct timeval	tv;
+	u_int		delay;
+
+	if (!window_pane_scrollbar_auto_hide(wp) || !wp->sb_auto_visible)
+		return;
+
+	delay = options_get_number(wp->window->options,
+	    "pane-scrollbars-timeout");
+	tv.tv_sec = delay / 1000;
+	tv.tv_usec = (delay % 1000) * 1000L;
+	evtimer_del(&wp->sb_auto_timer);
+	evtimer_add(&wp->sb_auto_timer, &tv);
+}
+
+void
+window_pane_scrollbar_show(struct window_pane *wp, int start_timer)
+{
+	int	changed = 0;
+	int	sb;
+
+	if (!window_pane_scrollbar_auto_hide(wp))
+		return;
+	sb = options_get_number(wp->window->options, "pane-scrollbars");
+	if (!window_pane_show_scrollbar(wp, sb))
+		return;
+	if (!wp->sb_auto_visible) {
+		wp->sb_auto_visible = 1;
+		changed = 1;
+	}
+	evtimer_del(&wp->sb_auto_timer);
+	if (start_timer)
+		window_pane_scrollbar_start_timer(wp);
+	if (changed)
+		window_pane_scrollbar_redraw_visibility(wp);
+}
+
+void
+window_pane_scrollbar_hide(struct window_pane *wp)
+{
+	if (event_initialized(&wp->sb_auto_timer))
+		evtimer_del(&wp->sb_auto_timer);
+	wp->sb_auto_hover = 0;
+	if (!wp->sb_auto_visible)
+		return;
+	wp->sb_auto_visible = 0;
+	window_pane_scrollbar_redraw_visibility(wp);
+}
+
 int
 window_pane_get_bg(struct window_pane *wp)
 {

From ad74c5ed7f62913d38543ff6843f38d14689b56d Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Mon, 29 Jun 2026 10:20:38 +0100
Subject: [PATCH 12/14] Add additional grid consistency checks for macOS.

---
 grid.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 46 insertions(+), 3 deletions(-)

diff --git a/grid.c b/grid.c
index 44efa574d..28680cbdd 100644
--- a/grid.c
+++ b/grid.c
@@ -18,6 +18,9 @@
 
 #include <sys/types.h>
 
+#ifdef __APPLE__
+#include <assert.h>
+#endif
 #include <stdlib.h>
 #include <string.h>
 
@@ -56,6 +59,28 @@ static const struct grid_cell_entry grid_cleared_entry = {
 	{ .data = { 0, 8, 8, ' ' } }, GRID_FLAG_CLEARED
 };
 
+#ifdef __APPLE__
+static void
+grid_check_lines(struct grid *gd)
+{
+	u_int	i, j;
+
+	for (i = 0; i < gd->hsize + gd->sy; i++) {
+		for (j = i + 1; j < gd->hsize + gd->sy; j++) {
+			if (gd->linedata[i].celldata != NULL)
+				assert(gd->linedata[i].celldata != gd->linedata[j].celldata);
+			if (gd->linedata[i].extddata != NULL)
+				assert(gd->linedata[i].extddata != gd->linedata[j].extddata);
+		}
+	}
+}
+#else
+static void
+grid_check_lines(__unused struct grid *gd)
+{
+}
+#endif
+
 /* Store cell in entry. */
 static void
 grid_store_cell(struct grid_cell_entry *gce, const struct grid_cell *gc,
@@ -287,9 +312,17 @@ grid_set_tab(struct grid_cell *gc, u_int width)
 static void
 grid_free_line(struct grid *gd, u_int py)
 {
-	free(gd->linedata[py].celldata);
-	free(gd->linedata[py].extddata);
-	memset(&gd->linedata[py], 0, sizeof gd->linedata[py]);
+	struct grid_line	*gl = &gd->linedata[py];
+
+#ifdef __APPLE__
+	assert(gl->cellused <= gl->cellsize);
+	assert(gl->extdsize == 0 || gl->extddata != NULL);
+	assert(gl->cellsize == 0 || gl->celldata != NULL);
+#endif
+
+	free(gl->celldata);
+	free(gl->extddata);
+	memset(gl, 0, sizeof *gl);
 }
 
 /* Free several lines. */
@@ -449,6 +482,8 @@ grid_scroll_history(struct grid *gd, u_int bg)
 	gd->linedata[gd->hsize].time = current_time;
 	gd->hsize++;
 	gd->scroll_added++;
+
+	grid_check_lines(gd);
 }
 
 /* Clear the history. */
@@ -498,6 +533,8 @@ grid_scroll_history_region(struct grid *gd, u_int upper, u_int lower, u_int bg)
 	gd->hscrolled++;
 	gd->hsize++;
 	gd->scroll_added++;
+
+	grid_check_lines(gd);
 }
 
 /* Expand line to fit to cell. */
@@ -759,6 +796,8 @@ grid_move_lines(struct grid *gd, u_int dy, u_int py, u_int ny, u_int bg)
 	}
 	if (py != 0 && (py < dy || py >= dy + ny))
 		gd->linedata[py - 1].flags &= ~GRID_LINE_WRAPPED;
+
+	grid_check_lines(gd);
 }
 
 /* Move a group of cells. */
@@ -1248,6 +1287,8 @@ grid_duplicate_lines(struct grid *dst, u_int dy, struct grid *src, u_int sy,
 		sy++;
 		dy++;
 	}
+
+	grid_check_lines(dst);
 }
 
 /* Mark line as dead. */
@@ -1544,6 +1585,8 @@ grid_reflow(struct grid *gd, u_int sx)
 	gd->linedata = target->linedata;
 	free(target);
 	gd->scroll_generation++;
+
+	grid_check_lines(gd);
 }
 
 /* Convert to position based on wrapped lines. */

From 5df51a06f5f830ee53ab78a50ed51d4901b4f72c Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Mon, 29 Jun 2026 16:20:45 +0000
Subject: [PATCH 13/14] Allow empty window and session names.

---
 tmux.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tmux.c b/tmux.c
index 7236360bb..9ea6b7fea 100644
--- a/tmux.c
+++ b/tmux.c
@@ -291,7 +291,7 @@ clean_name(const char *name, const char* forbid)
 {
 	char	*copy, *cp, *new_name;
 
-	if (*name == '\0' || !utf8_isvalid(name))
+	if (!utf8_isvalid(name))
 		return (NULL);
 	copy = xstrdup(name);
 	for (cp = copy; *cp != '\0'; cp++) {
@@ -316,7 +316,7 @@ check_name(const char *name, const char *forbid)
 {
 	const char	*cp;
 
-	if (*name == '\0' || !utf8_isvalid(name))
+	if (!utf8_isvalid(name))
 		return (0);
 	for (cp = name; *cp != '\0'; cp++) {
 		if (strchr(forbid, *cp) != NULL)

From 95719e342df89cf5c9e0c5f14994c6b681905dd6 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Mon, 29 Jun 2026 16:44:06 +0000
Subject: [PATCH 14/14] Limit hyperlink URIs to 1024 bytes which seems enough
 and allows us not to have to worry about gigantic URIs in styles, part of a
 change from Moritz Angermann.

---
 hyperlinks.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/hyperlinks.c b/hyperlinks.c
index c8fd0ca2f..a71827272 100644
--- a/hyperlinks.c
+++ b/hyperlinks.c
@@ -42,6 +42,7 @@
  */
 
 #define MAX_HYPERLINKS 5000
+#define MAX_HYPERLINK_URI 1024
 
 static long long hyperlinks_next_external_id = 1;
 static u_int global_hyperlinks_count;
@@ -146,9 +147,13 @@ hyperlinks_put(struct hyperlinks *hl, const char *uri_in,
 		internal_id_in = "";
 
 	utf8_stravis(&uri, uri_in, VIS_OCTAL|VIS_CSTYLE);
-	utf8_stravis(&internal_id, internal_id_in, VIS_OCTAL|VIS_CSTYLE);
+	if (strlen(uri) > MAX_HYPERLINK_URI) {
+		free(uri);
+		return (0);
+	}
 
-	if (*internal_id_in != '\0') {
+	utf8_stravis(&internal_id, internal_id_in, VIS_OCTAL|VIS_CSTYLE);
+	if (*internal_id != '\0') {
 		find.uri = uri;
 		find.internal_id = internal_id;