From 34e2035badecb6dbbfa343129c9e64db1d62ac24 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Tue, 19 May 2026 09:48:14 +0000
Subject: [PATCH] More bits for pane Z index tracking from floating panes,
 mostly by Michael Grant.

---
 cmd-break-pane.c |  2 ++
 cmd-join-pane.c  |  8 ++++++--
 format.c         | 18 +++++++++++-------
 layout-custom.c  |  9 +++++++++
 layout.c         | 24 ++++++++++++++++++++++++
 tmux.h           |  1 +
 window.c         | 49 ++++++++++++++++++++++++++++++++++++++----------
 7 files changed, 92 insertions(+), 19 deletions(-)

diff --git a/cmd-break-pane.c b/cmd-break-pane.c
index 790b8df2..aad23334 100644
--- a/cmd-break-pane.c
+++ b/cmd-break-pane.c
@@ -96,6 +96,7 @@ cmd_break_pane_exec(struct cmd *self, struct cmdq_item *item)
 	}
 
 	TAILQ_REMOVE(&w->panes, wp, entry);
+        TAILQ_REMOVE(&w->z_index, wp, zentry);
 	server_client_remove_pane(wp);
 	window_lost_pane(w, wp);
 	layout_close_pane(wp);
@@ -104,6 +105,7 @@ cmd_break_pane_exec(struct cmd *self, struct cmdq_item *item)
 	options_set_parent(wp->options, w->options);
 	wp->flags |= (PANE_STYLECHANGED|PANE_THEMECHANGED);
 	TAILQ_INSERT_HEAD(&w->panes, wp, entry);
+        TAILQ_INSERT_HEAD(&w->z_index, wp, zentry);
 	w->active = wp;
 	w->latest = tc;
 
diff --git a/cmd-join-pane.c b/cmd-join-pane.c
index f8975a67..7ff8859f 100644
--- a/cmd-join-pane.c
+++ b/cmd-join-pane.c
@@ -147,14 +147,18 @@ cmd_join_pane_exec(struct cmd *self, struct cmdq_item *item)
 	server_client_remove_pane(src_wp);
 	window_lost_pane(src_w, src_wp);
 	TAILQ_REMOVE(&src_w->panes, src_wp, entry);
+        TAILQ_REMOVE(&src_w->z_index, src_wp, zentry);
 
 	src_wp->window = dst_w;
 	options_set_parent(src_wp->options, dst_w->options);
 	src_wp->flags |= (PANE_STYLECHANGED|PANE_THEMECHANGED);
-	if (flags & SPAWN_BEFORE)
+	if (flags & SPAWN_BEFORE) {
 		TAILQ_INSERT_BEFORE(dst_wp, src_wp, entry);
-	else
+                TAILQ_INSERT_BEFORE(dst_wp, src_wp, zentry);
+	} else {
 		TAILQ_INSERT_AFTER(&dst_w->panes, dst_wp, src_wp, entry);
+		TAILQ_INSERT_AFTER(&dst_w->z_index, dst_wp, src_wp, zentry);
+	}
 	layout_assign_pane(lc, src_wp, 0);
 	colour_palette_from_option(&src_wp->palette, src_wp->options);
 
diff --git a/format.c b/format.c
index 472316ec..6766427f 100644
--- a/format.c
+++ b/format.c
@@ -1170,9 +1170,9 @@ format_cb_pane_at_bottom(struct format_tree *ft)
 
 	status = options_get_number(w->options, "pane-border-status");
 	if (status == PANE_STATUS_BOTTOM)
-		flag = (wp->yoff + wp->sy == w->sy - 1);
+		flag = (wp->yoff + (int)wp->sy == (int)w->sy - 1);
 	else
-		flag = (wp->yoff + wp->sy == w->sy);
+		flag = (wp->yoff + (int)wp->sy == (int)w->sy);
 	xasprintf(&value, "%d", flag);
 	return (value);
 }
@@ -2034,7 +2034,7 @@ static void *
 format_cb_pane_at_right(struct format_tree *ft)
 {
 	if (ft->wp != NULL) {
-		if (ft->wp->xoff + ft->wp->sx == ft->wp->window->sx)
+		if (ft->wp->xoff + (int)ft->wp->sx == (int)ft->wp->window->sx)
 			return (xstrdup("1"));
 		return (xstrdup("0"));
 	}
@@ -2045,8 +2045,10 @@ format_cb_pane_at_right(struct format_tree *ft)
 static void *
 format_cb_pane_bottom(struct format_tree *ft)
 {
-	if (ft->wp != NULL)
-		return (format_printf("%d", ft->wp->yoff + ft->wp->sy - 1));
+	struct window_pane	*wp = ft->wp;
+
+	if (wp != NULL)
+		return (format_printf("%d", wp->yoff + (int)wp->sy - 1));
 	return (NULL);
 }
 
@@ -2328,8 +2330,10 @@ format_cb_pane_pb_state(struct format_tree *ft)
 static void *
 format_cb_pane_right(struct format_tree *ft)
 {
-	if (ft->wp != NULL)
-		return (format_printf("%d", ft->wp->xoff + ft->wp->sx - 1));
+	struct window_pane	*wp = ft->wp;
+
+	if (wp != NULL)
+		return (format_printf("%d", wp->xoff + (int)wp->sx - 1));
 	return (NULL);
 }
 
diff --git a/layout-custom.c b/layout-custom.c
index aa36d2c4..054be77f 100644
--- a/layout-custom.c
+++ b/layout-custom.c
@@ -288,6 +288,15 @@ layout_parse(struct window *w, const char *layout, char **cause)
 	if (floating_lc != NULL)
 		layout_assign(&wp, floating_lc, PANE_FLOATING);
 
+        /* Fix pane Z indexes. */
+        while (!TAILQ_EMPTY(&w->z_index)) {
+                wp = TAILQ_FIRST(&w->z_index);
+		TAILQ_REMOVE(&w->z_index, wp, zentry);
+	}
+	if (floating_lc != NULL)
+		layout_fix_zindexes(w, floating_lc);
+	layout_fix_zindexes(w, tiled_lc);
+
 	/* Update pane offsets and sizes. */
 	layout_fix_offsets(w);
 	layout_fix_panes(w, NULL);
diff --git a/layout.c b/layout.c
index 5afd697b..407c5a05 100644
--- a/layout.c
+++ b/layout.c
@@ -233,6 +233,30 @@ layout_make_node(struct layout_cell *lc, enum layout_type type)
 	lc->wp = NULL;
 }
 
+/* Fix Z indexes. */
+void
+layout_fix_zindexes(struct window *w, struct layout_cell *lc)
+{
+	struct layout_cell	*lcchild;
+
+	if (lc == NULL)
+		return;
+
+	switch (lc->type) {
+	case LAYOUT_WINDOWPANE:
+		TAILQ_INSERT_TAIL(&w->z_index, lc->wp, zentry);
+	        break;
+	case LAYOUT_LEFTRIGHT:
+	case LAYOUT_TOPBOTTOM:
+	case LAYOUT_FLOATING:
+		TAILQ_FOREACH(lcchild, &lc->cells, entry)
+	                layout_fix_zindexes(w, lcchild);
+	        return;
+	default:
+	        fatalx("bad layout type");
+	}
+}
+
 /* Fix cell offsets for a child cell. */
 static void
 layout_fix_offsets1(struct layout_cell *lc)
diff --git a/tmux.h b/tmux.h
index 2209732e..5ac1d4f7 100644
--- a/tmux.h
+++ b/tmux.h
@@ -3438,6 +3438,7 @@ struct layout_cell *layout_search_by_border(struct layout_cell *, u_int, u_int);
 void             layout_set_size(struct layout_cell *, u_int, u_int, int, int);
 void		 layout_make_leaf(struct layout_cell *, struct window_pane *);
 void		 layout_make_node(struct layout_cell *, enum layout_type);
+void		 layout_fix_zindexes(struct window *, struct layout_cell *);
 void		 layout_fix_offsets(struct window *);
 void		 layout_fix_panes(struct window *, struct window_pane *);
 void		 layout_resize_adjust(struct window *, struct layout_cell *,
diff --git a/window.c b/window.c
index 72ccb7cc..ac48246f 100644
--- a/window.c
+++ b/window.c
@@ -585,6 +585,14 @@ window_redraw_active_switch(struct window *w, struct window_pane *wp)
 					wp->flags |= PANE_REDRAW;
 			}
 		}
+
+		/* If the pane is floating, move to the front. */
+		if (wp->flags & PANE_FLOATING) {
+			TAILQ_REMOVE(&w->z_index, wp, zentry);
+			TAILQ_INSERT_HEAD(&w->z_index, wp, zentry);
+			wp->flags |= PANE_REDRAW;
+		}
+
 		if (wp == w->active)
 			break;
 		wp = w->active;
@@ -600,18 +608,32 @@ window_get_active_at(struct window *w, u_int x, u_int y)
 
 	pane_status = options_get_number(w->options, "pane-border-status");
 
-	TAILQ_FOREACH(wp, &w->panes, entry) {
+	TAILQ_FOREACH(wp, &w->z_index, zentry) {
 		if (!window_pane_visible(wp))
 			continue;
 		window_pane_full_size_offset(wp, &xoff, &yoff, &sx, &sy);
-		if ((int)x < xoff || x > xoff + sx)
-			continue;
-		if (pane_status == PANE_STATUS_TOP) {
-			if ((int)y <= yoff - 2 || y > yoff + sy - 1)
+		if (~wp->flags & PANE_FLOATING) {
+			/* Tiled - to and including bottom or right border.  */
+			if ((int)x < xoff || x > xoff + sx)
 				continue;
+			if (pane_status == PANE_STATUS_TOP) {
+				if ((int)y < yoff - 1 || y > yoff + sy)
+					continue;
+			} else {
+				if ((int)y < yoff || y > yoff + sy)
+					continue;
+			}
 		} else {
-			if ((int)y < yoff || y > yoff + sy)
+			/* Floating - include top or or left border. */
+			if ((int)x < xoff - 1 || x > xoff + sx)
 				continue;
+			if (pane_status == PANE_STATUS_TOP) {
+				if ((int)y <= yoff - 2 || y > yoff + sy - 1)
+					continue;
+			} else {
+				if ((int)y < yoff - 1 || y > yoff + sy)
+					continue;
+			}
 		}
 		return (wp);
 	}
@@ -762,6 +784,12 @@ window_add_pane(struct window *w, struct window_pane *other, u_int hlimit,
 		else
 			TAILQ_INSERT_AFTER(&w->panes, other, wp, entry);
 	}
+	if (~flags & SPAWN_FLOATING)
+		TAILQ_INSERT_TAIL(&w->z_index, wp, zentry);
+	else {
+		TAILQ_INSERT_HEAD(&w->z_index, wp, zentry);
+		wp->flags |= PANE_FLOATING;
+	}
 	return (wp);
 }
 
@@ -794,8 +822,8 @@ void
 window_remove_pane(struct window *w, struct window_pane *wp)
 {
 	window_lost_pane(w, wp);
-
 	TAILQ_REMOVE(&w->panes, wp, entry);
+	TAILQ_REMOVE(&w->z_index, wp, zentry);
 	window_pane_destroy(wp);
 }
 
@@ -861,7 +889,7 @@ window_count_panes(struct window *w, int with_floating)
 	u_int			 n = 0;
 
 	TAILQ_FOREACH(wp, &w->panes, entry) {
-                if (with_floating || ~wp->flags & PANE_FLOATING)
+		if (with_floating || ~wp->flags & PANE_FLOATING)
 			n++;
 	}
 	return (n);
@@ -880,6 +908,7 @@ window_destroy_panes(struct window *w)
 	while (!TAILQ_EMPTY(&w->panes)) {
 		wp = TAILQ_FIRST(&w->panes);
 		TAILQ_REMOVE(&w->panes, wp, entry);
+		TAILQ_REMOVE(&w->z_index, wp, zentry);
 		window_pane_destroy(wp);
 	}
 }
@@ -1214,7 +1243,7 @@ window_pane_reset_mode_all(struct window_pane *wp)
 static void
 window_pane_copy_paste(struct window_pane *wp, char *buf, size_t len)
 {
- 	struct window_pane	*loop;
+	struct window_pane	*loop;
 
 	TAILQ_FOREACH(loop, &wp->window->panes, entry) {
 		if (loop != wp &&
@@ -1232,7 +1261,7 @@ window_pane_copy_paste(struct window_pane *wp, char *buf, size_t len)
 static void
 window_pane_copy_key(struct window_pane *wp, key_code key)
 {
- 	struct window_pane	*loop;
+	struct window_pane	*loop;
 
 	TAILQ_FOREACH(loop, &wp->window->panes, entry) {
 		if (loop != wp &&