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.

1 files changed, 20 insertions, 6 deletions

diff --git a/tty.c b/tty.c
index d3a4ba1d..cbdbec8d 100644
--- a/tty.c
+++ b/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)