Tidy up the terminal detection and feature code and add named sets of

terminal features, each of which are defined in one place and map to a
builtin set of terminfo(5) capabilities. Features can be specified based
on TERM with a new terminal-features option or with the -T flag when
running tmux. tmux will also detect a few common terminals from the DA
and DSR responses.

This is intended to make it easier to configure tmux's use of
terminfo(5) even in the presence of outdated ncurses(3) or terminfo(5)
databases or for features which do not yet have a terminfo(5) entry.
Instead of having to grok terminfo(5) capability names and what they
should be set to in the terminal-overrides option, the user can
hopefully just give tmux a feature name and let it do the right thing.

The terminal-overrides option remains both for backwards compatibility
and to allow tweaks of individual capabilities.

tmux already did much of this already, this makes it tidier and simpler
to configure.

1 files changed, 33 insertions, 88 deletions

diff --git a/tty.c b/tty.c
index cdfedf6c..dfc35873 100644
--- a/tty.c
+++ b/tty.c
@@ -74,7 +74,7 @@ static void	tty_default_attributes(struct tty *, struct window_pane *,
 		    u_int);
 
 #define tty_use_margin(tty) \
-	(tty_get_flags(tty) & TERM_DECSLRM)
+	(tty->term->flags & TERM_DECSLRM)
 
 #define tty_pane_full_width(tty, ctx) \
 	((ctx)->xoff == 0 && screen_size_x((ctx)->wp->screen) >= (tty)->sx)
@@ -96,27 +96,19 @@ tty_create_log(void)
 }
 
 int
-tty_init(struct tty *tty, struct client *c, int fd, char *term)
+tty_init(struct tty *tty, struct client *c, int fd)
 {
 	if (!isatty(fd))
 		return (-1);
 
 	memset(tty, 0, sizeof *tty);
 
-	if (term == NULL || *term == '\0')
-		tty->term_name = xstrdup("unknown");
-	else
-		tty->term_name = xstrdup(term);
-
 	tty->fd = fd;
 	tty->client = c;
 
 	tty->cstyle = 0;
 	tty->ccolour = xstrdup("");
 
-	tty->flags = 0;
-	tty->term_flags = 0;
-
 	return (0);
 }
 
@@ -256,7 +248,10 @@ tty_write_callback(__unused int fd, __unused short events, void *data)
 int
 tty_open(struct tty *tty, char **cause)
 {
-	tty->term = tty_term_find(tty->term_name, tty->fd, cause);
+	struct client	*c = tty->client;
+
+	tty->term = tty_term_create(tty, c->term_name, &c->term_features,
+	    tty->fd, cause);
 	if (tty->term == NULL) {
 		tty_close(tty);
 		return (-1);
@@ -466,28 +461,20 @@ void
 tty_free(struct tty *tty)
 {
 	tty_close(tty);
-
 	free(tty->ccolour);
-	free(tty->term_name);
 }
 
 void
-tty_set_flags(struct tty *tty, int flags)
+tty_update_features(struct tty *tty)
 {
-	tty->term_flags |= flags;
+	struct client	*c = tty->client;
+
+	tty_apply_features(tty->term, c->term_features);
 
 	if (tty_use_margin(tty))
 		tty_puts(tty, "\033[?69h"); /* DECLRMM */
 }
 
-int
-tty_get_flags(struct tty *tty)
-{
-	if (tty->term != NULL)
-		return (tty->term->flags|tty->term_flags);
-	return (tty->term_flags);
-}
-
 void
 tty_raw(struct tty *tty, const char *s)
 {
@@ -585,7 +572,7 @@ tty_putc(struct tty *tty, u_char ch)
 {
 	const char	*acs;
 
-	if ((tty_get_flags(tty) & TERM_NOXENL) &&
+	if ((tty->term->flags & TERM_NOXENL) &&
 	    ch >= 0x20 && ch != 0x7f &&
 	    tty->cy == tty->sy - 1 &&
 	    tty->cx + 1 >= tty->sx)
@@ -611,7 +598,7 @@ tty_putc(struct tty *tty, u_char ch)
 			 * where we think it should be after a line wrap - this
 			 * means it works on sensible terminals as well.
 			 */
-			if (tty_get_flags(tty) & TERM_NOXENL)
+			if (tty->term->flags & TERM_NOXENL)
 				tty_putcode2(tty, TTYC_CUP, tty->cy, tty->cx);
 		} else
 			tty->cx++;
@@ -621,7 +608,7 @@ tty_putc(struct tty *tty, u_char ch)
 void
 tty_putn(struct tty *tty, const void *buf, size_t len, u_int width)
 {
-	if ((tty_get_flags(tty) & TERM_NOXENL) &&
+	if ((tty->term->flags & TERM_NOXENL) &&
 	    tty->cy == tty->sy - 1 &&
 	    tty->cx + len >= tty->sx)
 		len = tty->sx - tty->cx - 1;
@@ -1179,7 +1166,7 @@ tty_clear_area(struct tty *tty, struct window_pane *wp, u_int py, u_int ny,
 		 * background colour isn't default (because it doesn't work
 		 * after SGR 0).
 		 */
-		if ((tty_get_flags(tty) & TERM_DECFRA) && !COLOUR_DEFAULT(bg)) {
+		if ((tty->term->flags & TERM_DECFRA) && !COLOUR_DEFAULT(bg)) {
 			xsnprintf(tmp, sizeof tmp, "\033[32;%u;%u;%u;%u$x",
 			    py + 1, px + 1, py + ny, px + nx);
 			tty_puts(tty, tmp);
@@ -1258,7 +1245,7 @@ tty_check_codeset(struct tty *tty, const struct grid_cell *gc)
 		return (gc);
 
 	/* UTF-8 terminal and a UTF-8 character - fine. */
-	if (tty_get_flags(tty) & TERM_UTF8)
+	if (tty->client->flags & CLIENT_UTF8)
 		return (gc);
 
 	/* Replace by the right number of underscores. */
@@ -1440,7 +1427,7 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 void
 tty_sync_start(struct tty *tty)
 {
-	if ((~tty->flags & TTY_SYNCING) && (tty_get_flags(tty) & TERM_SYNC)) {
+	if ((~tty->flags & TTY_SYNCING) && tty_term_has(tty->term, TTYC_SYNC)) {
 		tty_puts(tty, "\033P=1s\033\\");
 		tty->flags |= TTY_SYNCING;
 	}
@@ -1449,7 +1436,7 @@ tty_sync_start(struct tty *tty)
 void
 tty_sync_end(struct tty *tty)
 {
-	if (tty_get_flags(tty) & TERM_SYNC) {
+	if ((tty->flags & TTY_SYNCING) && tty_term_has(tty->term, TTYC_SYNC)) {
 		tty_puts(tty, "\033P=2s\033\\");
 		tty->flags &= ~TTY_SYNCING;
 	}
@@ -1916,7 +1903,7 @@ tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
 	    ctx->xoff + ctx->ocx + ctx->num > ctx->ox + ctx->sx)) {
 		if (!ctx->wrapped ||
 		    !tty_pane_full_width(tty, ctx) ||
-		    (tty_get_flags(tty) & TERM_NOXENL) ||
+		    (tty->term->flags & TERM_NOXENL) ||
 		    ctx->xoff + ctx->ocx != 0 ||
 		    ctx->yoff + ctx->ocy != tty->cy + 1 ||
 		    tty->cx < tty->sx ||
@@ -1977,7 +1964,7 @@ tty_cell(struct tty *tty, const struct grid_cell *gc, struct window_pane *wp)
 	const struct grid_cell	*gcp;
 
 	/* Skip last character if terminal is stupid. */
-	if ((tty_get_flags(tty) & TERM_NOXENL) &&
+	if ((tty->term->flags & TERM_NOXENL) &&
 	    tty->cy == tty->sy - 1 &&
 	    tty->cx == tty->sx - 1)
 		return;
@@ -2140,7 +2127,7 @@ tty_cursor_pane_unless_wrap(struct tty *tty, const struct tty_ctx *ctx,
 {
 	if (!ctx->wrapped ||
 	    !tty_pane_full_width(tty, ctx) ||
-	    (tty_get_flags(tty) & TERM_NOXENL) ||
+	    (tty->term->flags & TERM_NOXENL) ||
 	    ctx->xoff + cx != 0 ||
 	    ctx->yoff + cy != tty->cy + 1 ||
 	    tty->cx < tty->sx ||
@@ -2480,14 +2467,14 @@ tty_check_fg(struct tty *tty, struct window_pane *wp, struct grid_cell *gc)
 	/* Is this a 24-bit colour? */
 	if (gc->fg & COLOUR_FLAG_RGB) {
 		/* Not a 24-bit terminal? Translate to 256-colour palette. */
-		if (tty_get_flags(tty) & TERM_RGBCOLOURS)
+		if (tty->term->flags & TERM_RGBCOLOURS)
 			return;
 		colour_split_rgb(gc->fg, &r, &g, &b);
 		gc->fg = colour_find_rgb(r, g, b);
 	}
 
 	/* How many colours does this terminal have? */
-	if (tty_get_flags(tty) & TERM_256COLOURS)
+	if (tty->term->flags & TERM_256COLOURS)
 		colours = 256;
 	else
 		colours = tty_term_number(tty->term, TTYC_COLORS);
@@ -2529,14 +2516,14 @@ tty_check_bg(struct tty *tty, struct window_pane *wp, struct grid_cell *gc)
 	/* Is this a 24-bit colour? */
 	if (gc->bg & COLOUR_FLAG_RGB) {
 		/* Not a 24-bit terminal? Translate to 256-colour palette. */
-		if (tty_get_flags(tty) & TERM_RGBCOLOURS)
+		if (tty->term->flags & TERM_RGBCOLOURS)
 			return;
 		colour_split_rgb(gc->bg, &r, &g, &b);
 		gc->bg = colour_find_rgb(r, g, b);
 	}
 
 	/* How many colours does this terminal have? */
-	if (tty_get_flags(tty) & TERM_256COLOURS)
+	if (tty->term->flags & TERM_256COLOURS)
 		colours = 256;
 	else
 		colours = tty_term_number(tty->term, TTYC_COLORS);
@@ -2597,7 +2584,7 @@ tty_colours_fg(struct tty *tty, const struct grid_cell *gc)
 
 	/* Is this an aixterm bright colour? */
 	if (gc->fg >= 90 && gc->fg <= 97) {
-		if (tty_get_flags(tty) & TERM_256COLOURS) {
+		if (tty->term->flags & TERM_256COLOURS) {
 			xsnprintf(s, sizeof s, "\033[%dm", gc->fg);
 			tty_puts(tty, s);
 		} else
@@ -2629,7 +2616,7 @@ tty_colours_bg(struct tty *tty, const struct grid_cell *gc)
 
 	/* Is this an aixterm bright colour? */
 	if (gc->bg >= 90 && gc->bg <= 97) {
-		if (tty_get_flags(tty) & TERM_256COLOURS) {
+		if (tty->term->flags & TERM_256COLOURS) {
 			xsnprintf(s, sizeof s, "\033[%dm", gc->bg + 10);
 			tty_puts(tty, s);
 		} else
@@ -2674,67 +2661,25 @@ static int
 tty_try_colour(struct tty *tty, int colour, const char *type)
 {
 	u_char	r, g, b;
-	char	s[32];
 
 	if (colour & COLOUR_FLAG_256) {
-		/*
-		 * If the user has specified -2 to the client (meaning
-		 * TERM_256COLOURS is set), setaf and setab may not work (or
-		 * they may not want to use them), so send the usual sequence.
-		 *
-		 * Also if RGB is set, setaf and setab do not support the 256
-		 * colour palette so use the sequences directly there too.
-		 */
-		if ((tty_get_flags(tty) & TERM_256COLOURS) ||
-		    tty_term_has(tty->term, TTYC_RGB))
-			goto fallback_256;
-
-		/*
-		 * If the terminfo entry has 256 colours and setaf and setab
-		 * exist, assume that they work correctly.
-		 */
-		if (tty_get_flags(tty) & TERM_256COLOURS) {
-			if (*type == '3') {
-				if (!tty_term_has(tty->term, TTYC_SETAF))
-					goto fallback_256;
-				tty_putcode1(tty, TTYC_SETAF, colour & 0xff);
-			} else {
-				if (!tty_term_has(tty->term, TTYC_SETAB))
-					goto fallback_256;
-				tty_putcode1(tty, TTYC_SETAB, colour & 0xff);
-			}
-			return (0);
-		}
-		goto fallback_256;
+		if (*type == '3' && tty_term_has(tty->term, TTYC_SETAF))
+			tty_putcode1(tty, TTYC_SETAF, colour & 0xff);
+		else if (tty_term_has(tty->term, TTYC_SETAB))
+			tty_putcode1(tty, TTYC_SETAB, colour & 0xff);
+		return (0);
 	}
 
 	if (colour & COLOUR_FLAG_RGB) {
 		colour_split_rgb(colour & 0xffffff, &r, &g, &b);
-		if (*type == '3') {
-			if (!tty_term_has(tty->term, TTYC_SETRGBF))
-				goto fallback_rgb;
+		if (*type == '3' && tty_term_has(tty->term, TTYC_SETRGBF))
 			tty_putcode3(tty, TTYC_SETRGBF, r, g, b);
-		} else {
-			if (!tty_term_has(tty->term, TTYC_SETRGBB))
-				goto fallback_rgb;
+		else if (tty_term_has(tty->term, TTYC_SETRGBB))
 			tty_putcode3(tty, TTYC_SETRGBB, r, g, b);
-		}
 		return (0);
 	}
 
 	return (-1);
-
-fallback_256:
-	xsnprintf(s, sizeof s, "\033[%s;5;%dm", type, colour & 0xff);
-	log_debug("%s: 256 colour fallback: %s", tty->client->name, s);
-	tty_puts(tty, s);
-	return (0);
-
-fallback_rgb:
-	xsnprintf(s, sizeof s, "\033[%s;2;%d;%d;%dm", type, r, g, b);
-	log_debug("%s: RGB colour fallback: %s", tty->client->name, s);
-	tty_puts(tty, s);
-	return (0);
 }
 
 static void