From 833c7fbf6d57481dd16f1fda78145e2f8b0be954 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Thu, 22 May 2025 07:43:38 +0000
Subject: [PATCH] Add a set-default style attribute which replaces the current
 default colours and attributes completely, useful at the start of compound
 format strings (like status-format) to set the default colours for all the
 following options.

---
 format-draw.c | 10 +++++++++-
 style.c       |  4 ++++
 tmux.1        |  4 ++++
 tmux.h        |  3 ++-
 4 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/format-draw.c b/format-draw.c
index a42dfe1d..efc6ab1a 100644
--- a/format-draw.c
+++ b/format-draw.c
@@ -719,7 +719,7 @@ format_draw(struct screen_write_ctx *octx, const struct grid_cell *base,
 	int			 focus_start = -1, focus_end = -1;
 	int			 list_state = -1, fill = -1, even;
 	enum style_align	 list_align = STYLE_ALIGN_DEFAULT;
-	struct grid_cell	 gc, current_default;
+	struct grid_cell	 gc, current_default, base_default;
 	struct style		 sy, saved_sy;
 	struct utf8_data	*ud = &sy.gc.data;
 	const char		*cp, *end;
@@ -729,7 +729,9 @@ format_draw(struct screen_write_ctx *octx, const struct grid_cell *base,
 	struct format_ranges	 frs;
 	struct style_range	*sr;
 
+	memcpy(&base_default, base, sizeof base_default);
 	memcpy(&current_default, base, sizeof current_default);
+	base = &base_default;
 	style_set(&sy, &current_default);
 	TAILQ_INIT(&frs);
 	log_debug("%s: %s", __func__, expanded);
@@ -847,6 +849,12 @@ format_draw(struct screen_write_ctx *octx, const struct grid_cell *base,
 		} else if (sy.default_type == STYLE_DEFAULT_POP) {
 			memcpy(&current_default, base, sizeof current_default);
 			sy.default_type = STYLE_DEFAULT_BASE;
+		} else if (sy.default_type == STYLE_DEFAULT_SET) {
+			memcpy(&base_default, &saved_sy.gc,
+			    sizeof base_default);
+			memcpy(&current_default, &saved_sy.gc,
+			    sizeof current_default);
+			sy.default_type = STYLE_DEFAULT_BASE;
 		}
 
 		/* Check the list state. */
diff --git a/style.c b/style.c
index c9e5b15e..4e4f6fcc 100644
--- a/style.c
+++ b/style.c
@@ -98,6 +98,8 @@ style_parse(struct style *sy, const struct grid_cell *base, const char *in)
 			sy->default_type = STYLE_DEFAULT_PUSH;
 		else if (strcasecmp(tmp, "pop-default") == 0)
 			sy->default_type = STYLE_DEFAULT_POP;
+		else if (strcasecmp(tmp, "set-default") == 0)
+			sy->default_type = STYLE_DEFAULT_SET;
 		else if (strcasecmp(tmp, "nolist") == 0)
 			sy->list = STYLE_LIST_OFF;
 		else if (strncasecmp(tmp, "list=", 5) == 0) {
@@ -310,6 +312,8 @@ style_tostring(struct style *sy)
 			tmp = "push-default";
 		else if (sy->default_type == STYLE_DEFAULT_POP)
 			tmp = "pop-default";
+		else if (sy->default_type == STYLE_DEFAULT_SET)
+			tmp = "set-default";
 		off += xsnprintf(s + off, sizeof s - off, "%s%s", comma, tmp);
 		comma = ",";
 	}
diff --git a/tmux.1 b/tmux.1
index 250e781d..896c6164 100644
--- a/tmux.1
+++ b/tmux.1
@@ -6357,6 +6357,10 @@ will be available in the
 format variable.
 .Ql X
 must be at most 15 bytes in length.
+.It Ic set-default
+Set the current colours and attributes as the default, overwriting any previous
+default.
+The previous default cannot be restored.
 .El
 .Pp
 Examples are:
diff --git a/tmux.h b/tmux.h
index 7db37dc2..7bcd4e2e 100644
--- a/tmux.h
+++ b/tmux.h
@@ -881,7 +881,8 @@ TAILQ_HEAD(style_ranges, style_range);
 enum style_default_type {
 	STYLE_DEFAULT_BASE,
 	STYLE_DEFAULT_PUSH,
-	STYLE_DEFAULT_POP
+	STYLE_DEFAULT_POP,
+	STYLE_DEFAULT_SET
 };
 
 /* Style option. */