If colours are not supported by the terminal, try to emulate a coloured

background by setting or clearing the reverse attribute.

This makes a few applications which don't use the reverse attribute themselves
a little happier, and allows the status, message and mode options to have
default attributes and fg/bg options that work as expected when set as reverse.

status.c

@@ -64,8 +64,8 @@ status_redraw(struct client *c)
 	if (gettimeofday(&c->status_timer, NULL) != 0)
 		fatal("gettimeofday");
 	memcpy(&stdgc, &grid_default_cell, sizeof gc);
-	stdgc.bg = options_get_number(&s->options, "status-fg");
-	stdgc.fg = options_get_number(&s->options, "status-bg");
+	stdgc.fg = options_get_number(&s->options, "status-fg");
+	stdgc.bg = options_get_number(&s->options, "status-bg");
 	stdgc.attr |= options_get_number(&s->options, "status-attr");
 
 	yy = c->tty.sy - 1;
@@ -563,8 +563,8 @@ status_message_redraw(struct client *c)
 		len = c->tty.sx;
 
 	memcpy(&gc, &grid_default_cell, sizeof gc);
-	gc.bg = options_get_number(&s->options, "message-fg");
-	gc.fg = options_get_number(&s->options, "message-bg");
+	gc.fg = options_get_number(&s->options, "message-fg");
+	gc.bg = options_get_number(&s->options, "message-bg");
 	gc.attr |= options_get_number(&s->options, "message-attr");
 
 	screen_write_start(&ctx, NULL, &c->status);
@@ -662,8 +662,8 @@ status_prompt_redraw(struct client *c)
 		len = c->tty.sx;
 
 	memcpy(&gc, &grid_default_cell, sizeof gc);
-	gc.bg = options_get_number(&s->options, "message-fg");
-	gc.fg = options_get_number(&s->options, "message-bg");
+	gc.fg = options_get_number(&s->options, "message-fg");
+	gc.bg = options_get_number(&s->options, "message-bg");
 	gc.attr |= options_get_number(&s->options, "message-attr");
 
 	screen_write_start(&ctx, NULL, &c->status);

tmux.c

@@ -345,7 +345,7 @@ main(int argc, char **argv)
 	options_set_number(&global_s_options, "display-time", 750);
 	options_set_number(&global_s_options, "history-limit", 2000);
 	options_set_number(&global_s_options, "lock-after-time", 0);
-	options_set_number(&global_s_options, "message-attr", GRID_ATTR_REVERSE);
+	options_set_number(&global_s_options, "message-attr", 0);
 	options_set_number(&global_s_options, "message-bg", 3);
 	options_set_number(&global_s_options, "message-fg", 0);
 	options_set_number(&global_s_options, "prefix", '\002');
@@ -353,7 +353,7 @@ main(int argc, char **argv)
 	options_set_number(&global_s_options, "set-remain-on-exit", 0);
 	options_set_number(&global_s_options, "set-titles", 0);
 	options_set_number(&global_s_options, "status", 1);
-	options_set_number(&global_s_options, "status-attr", GRID_ATTR_REVERSE);
+	options_set_number(&global_s_options, "status-attr", 0);
 	options_set_number(&global_s_options, "status-bg", 2);
 	options_set_number(&global_s_options, "status-fg", 0);
 	options_set_number(&global_s_options, "status-interval", 15);
@@ -383,7 +383,7 @@ main(int argc, char **argv)
 	options_set_number(&global_w_options, "force-width", 0);
 	options_set_number(&global_w_options, "main-pane-width", 81);
 	options_set_number(&global_w_options, "main-pane-height", 24);
-	options_set_number(&global_w_options, "mode-attr", GRID_ATTR_REVERSE);
+	options_set_number(&global_w_options, "mode-attr", 0);
 	options_set_number(&global_w_options, "mode-bg", 3);
 	options_set_number(&global_w_options, "mode-fg", 0);
 	options_set_number(&global_w_options, "mode-keys", MODEKEY_EMACS);

tty.c

@@ -951,19 +951,33 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc)
 {
 	struct grid_cell	*tc = &tty->cell;
 	u_char			 changed;
-	u_int			 fg, bg;
+	u_int			 fg, bg, attr;
+
+	/*
+	 * If no setab, try to use the reverse attribute as a best-effort for a
+	 * non-default background. This is a bit of a hack but it doesn't do
+	 * any serious harm and makes a couple of applications happier.
+	 */
+	fg = gc->fg; bg = gc->bg; attr = gc->attr;
+	if (!tty_term_has(tty->term, TTYC_SETAB)) {
+		if (attr & GRID_ATTR_REVERSE) {
+			if (fg != 7 && fg != 8)
+				attr &= ~GRID_ATTR_REVERSE;
+		} else {
+			if (bg != 0 && bg != 8)
+				attr |= GRID_ATTR_REVERSE;
+		}
+	}
 
 	/* If any bits are being cleared, reset everything. */
-	if (tc->attr & ~gc->attr)
+	if (tc->attr & ~attr)
 		tty_reset(tty);
 
 	/* Filter out attribute bits already set. */
-	changed = gc->attr & ~tc->attr;
-	tc->attr = gc->attr;
+	changed = attr & ~tc->attr;
+	tc->attr = attr;
 
 	/* Set the attributes. */
-	fg = gc->fg;
-	bg = gc->bg;
 	if (changed & GRID_ATTR_BRIGHT)
 		tty_putcode(tty, TTYC_BOLD);
 	if (changed & GRID_ATTR_DIM)

window-choose.c

@@ -305,8 +305,8 @@ window_choose_write_line(
 	utf8flag = options_get_number(&wp->window->options, "utf8");
 	memcpy(&gc, &grid_default_cell, sizeof gc);
 	if (data->selected == data->top + py) {
-		gc.fg = options_get_number(&wp->window->options, "mode-bg");
-		gc.bg = options_get_number(&wp->window->options, "mode-fg");
+		gc.fg = options_get_number(&wp->window->options, "mode-fg");
+		gc.bg = options_get_number(&wp->window->options, "mode-bg");
 		gc.attr |= options_get_number(&wp->window->options, "mode-attr");
 	}
 

window-copy.c

@@ -264,8 +264,8 @@ window_copy_write_line(struct window_pane *wp, struct screen_write_ctx *ctx, u_i
 		memcpy(&gc, &grid_default_cell, sizeof gc);
 		size = xsnprintf(hdr, sizeof hdr,
 		    "[%u,%u/%u]", data->ox, data->oy, screen_hsize(&wp->base));
-		gc.bg = options_get_number(&wp->window->options, "mode-fg");
-		gc.fg = options_get_number(&wp->window->options, "mode-bg");
+		gc.fg = options_get_number(&wp->window->options, "mode-fg");
+		gc.bg = options_get_number(&wp->window->options, "mode-bg");
 		gc.attr |= options_get_number(&wp->window->options, "mode-attr");
 		screen_write_cursormove(ctx, screen_size_x(s) - size, 0);
 		screen_write_puts(ctx, &gc, "%s", hdr);
@@ -368,8 +368,8 @@ window_copy_update_selection(struct window_pane *wp)
 
 	/* Set colours. */
 	memcpy(&gc, &grid_default_cell, sizeof gc);
-	gc.bg = options_get_number(&wp->window->options, "mode-fg");
-	gc.fg = options_get_number(&wp->window->options, "mode-bg");
+	gc.fg = options_get_number(&wp->window->options, "mode-fg");
+	gc.bg = options_get_number(&wp->window->options, "mode-bg");
 	gc.attr |= options_get_number(&wp->window->options, "mode-attr");
 
 	/* Find top-left of screen. */

window-more.c

@@ -176,8 +176,8 @@ window_more_write_line(
 		size = xsnprintf(hdr, sizeof hdr,
 		    "[%u/%u]", data->top, ARRAY_LENGTH(&data->list));
 		screen_write_cursormove(ctx, screen_size_x(s) - size, 0);
-		gc.bg = options_get_number(&wp->window->options, "mode-fg");
-		gc.fg = options_get_number(&wp->window->options, "mode-bg");
+		gc.fg = options_get_number(&wp->window->options, "mode-fg");
+		gc.bg = options_get_number(&wp->window->options, "mode-bg");
 		gc.attr |= options_get_number(&wp->window->options, "mode-attr");
 		screen_write_puts(ctx, &gc, "%s", hdr);
 		memcpy(&gc, &grid_default_cell, sizeof gc);

window-scroll.c

@@ -176,8 +176,8 @@ window_scroll_write_line(
 		memcpy(&gc, &grid_default_cell, sizeof gc);
 		size = xsnprintf(hdr, sizeof hdr,
 		    "[%u,%u/%u]", data->ox, data->oy, screen_hsize(&wp->base));
-		gc.bg = options_get_number(&wp->window->options, "mode-fg");
-		gc.fg = options_get_number(&wp->window->options, "mode-bg");
+		gc.fg = options_get_number(&wp->window->options, "mode-fg");
+		gc.bg = options_get_number(&wp->window->options, "mode-bg");
 		gc.attr |= options_get_number(&wp->window->options, "mode-attr");
 		screen_write_cursormove(ctx, screen_size_x(s) - size, 0);
 		screen_write_puts(ctx, &gc, "%s", hdr);