Change cursor style handling so tmux understands which sequences contain

blinking and sets the flag appropriately, means that it works whether
cnorm disables blinking or not. GitHub issue 2682.

3 files changed, 123 insertions, 46 deletions

diff --git a/usr.bin/tmux/screen.c b/usr.bin/tmux/screen.c
index cb8aa867382..b578902bd92 100644
--- a/usr.bin/tmux/screen.c
+++ b/usr.bin/tmux/screen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen.c,v 1.71 2021/06/10 07:24:10 nicm Exp $ */
+/* $OpenBSD: screen.c,v 1.72 2021/06/10 07:36:47 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -81,7 +81,7 @@ screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
 	s->titles = NULL;
 	s->path = NULL;
 
-	s->cstyle = 0;
+	s->cstyle = SCREEN_CURSOR_DEFAULT;
 	s->ccolour = xstrdup("");
 	s->tabs = NULL;
 	s->sel = NULL;
@@ -156,9 +156,35 @@ screen_reset_tabs(struct screen *s)
 void
 screen_set_cursor_style(struct screen *s, u_int style)
 {
-	if (style <= 6) {
-		s->cstyle = style;
+	switch (style)
+	{
+	case 0:
+		s->cstyle = SCREEN_CURSOR_DEFAULT;
+		break;
+	case 1:
+		s->cstyle = SCREEN_CURSOR_BLOCK;
+		s->mode |= MODE_BLINKING;
+		break;
+	case 2:
+		s->cstyle = SCREEN_CURSOR_BLOCK;
 		s->mode &= ~MODE_BLINKING;
+		break;
+	case 3:
+		s->cstyle = SCREEN_CURSOR_UNDERLINE;
+		s->mode |= MODE_BLINKING;
+		break;
+	case 4:
+		s->cstyle = SCREEN_CURSOR_UNDERLINE;
+		s->mode &= ~MODE_BLINKING;
+		break;
+	case 5:
+		s->cstyle = SCREEN_CURSOR_BAR;
+		s->mode |= MODE_BLINKING;
+		break;
+	case 6:
+		s->cstyle = SCREEN_CURSOR_BAR;
+		s->mode &= ~MODE_BLINKING;
+		break;
 	}
 }
 
diff --git a/usr.bin/tmux/tmux.h b/usr.bin/tmux/tmux.h
index 21e522ad675..67f7d0eeb21 100644
--- a/usr.bin/tmux/tmux.h
+++ b/usr.bin/tmux/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1105 2021/06/10 07:33:41 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1106 2021/06/10 07:36:47 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -794,6 +794,14 @@ struct style {
 	enum style_default_type	default_type;
 };
 
+/* Cursor style. */
+enum screen_cursor_style {
+	SCREEN_CURSOR_DEFAULT,
+	SCREEN_CURSOR_BLOCK,
+	SCREEN_CURSOR_UNDERLINE,
+	SCREEN_CURSOR_BAR
+};
+
 /* Virtual screen. */
 struct screen_sel;
 struct screen_titles;
@@ -807,8 +815,8 @@ struct screen {
 	u_int				 cx;	  /* cursor x */
 	u_int				 cy;	  /* cursor y */
 
-	u_int				 cstyle;  /* cursor style */
-	char				*ccolour; /* cursor colour string */
+	enum screen_cursor_style	 cstyle;  /* cursor style */
+	char				*ccolour; /* cursor colour */
 
 	u_int				 rupper;  /* scroll region top */
 	u_int				 rlower;  /* scroll region bottom */
@@ -1296,7 +1304,7 @@ struct tty {
 
 	u_int		 cx;
 	u_int		 cy;
-	u_int		 cstyle;
+	enum screen_cursor_style cstyle;
 	char		*ccolour;
 
 	int		 oflag;
diff --git a/usr.bin/tmux/tty.c b/usr.bin/tmux/tty.c
index ba87484b588..58c4792ba61 100644
--- a/usr.bin/tmux/tty.c
+++ b/usr.bin/tmux/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.390 2021/03/12 08:39:17 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.391 2021/06/10 07:36:47 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -98,7 +98,7 @@ tty_init(struct tty *tty, struct client *c)
 	memset(tty, 0, sizeof *tty);
 	tty->client = c;
 
-	tty->cstyle = 0;
+	tty->cstyle = SCREEN_CURSOR_DEFAULT;
 	tty->ccolour = xstrdup("");
 
 	if (tcgetattr(c->fd, &tty->tio) != 0)
@@ -392,10 +392,10 @@ tty_stop_tty(struct tty *tty)
 	tty_raw(tty, tty_term_string(tty->term, TTYC_SGR0));
 	tty_raw(tty, tty_term_string(tty->term, TTYC_RMKX));
 	tty_raw(tty, tty_term_string(tty->term, TTYC_CLEAR));
-	if (tty_term_has(tty->term, TTYC_SS) && tty->cstyle != 0) {
+	if (tty->cstyle != SCREEN_CURSOR_DEFAULT) {
 		if (tty_term_has(tty->term, TTYC_SE))
 			tty_raw(tty, tty_term_string(tty->term, TTYC_SE));
-		else
+		else if (tty_term_has(tty->term, TTYC_SS))
 			tty_raw(tty, tty_term_string1(tty->term, TTYC_SS, 0));
 	}
 	if (tty->mode & MODE_BRACKETPASTE)
@@ -657,11 +657,9 @@ tty_force_cursor_colour(struct tty *tty, const char *ccolour)
 void
 tty_update_mode(struct tty *tty, int mode, struct screen *s)
 {
-	struct client	*c = tty->client;
-	int		 changed;
-
-	if (s != NULL && strcmp(s->ccolour, tty->ccolour) != 0)
-		tty_force_cursor_colour(tty, s->ccolour);
+	struct client		*c = tty->client;
+	int			 changed;
+	enum screen_cursor_style cstyle = tty->cstyle;
 
 	if (tty->flags & TTY_NOCURSOR)
 		mode &= ~MODE_CURSOR;
@@ -670,38 +668,83 @@ tty_update_mode(struct tty *tty, int mode, struct screen *s)
 	if (changed != 0)
 		log_debug("%s: update mode %x to %x", c->name, tty->mode, mode);
 
-	/*
-	 * The cursor blinking flag can be reset by setting the cursor style, so
-	 * set the style first.
-	 */
-	if (s != NULL && tty->cstyle != s->cstyle) {
-		if (tty_term_has(tty->term, TTYC_SS)) {
-			if (s->cstyle == 0 && tty_term_has(tty->term, TTYC_SE))
-				tty_putcode(tty, TTYC_SE);
-			else
-				tty_putcode1(tty, TTYC_SS, s->cstyle);
-		}
-		tty->cstyle = s->cstyle;
-		changed |= (MODE_CURSOR|MODE_BLINKING);
+	if (s != NULL) {
+		if (strcmp(s->ccolour, tty->ccolour) != 0)
+			tty_force_cursor_colour(tty, s->ccolour);
+		cstyle = s->cstyle;
 	}
-
-	/*
-	 * Cursor invisible (RM ?25) overrides cursor blinking (SM ?12 or RM
-	 * 34), and we need to be careful not send cnorm after cvvis since it
-	 * can undo it.
-	 */
-	if (changed & (MODE_CURSOR|MODE_BLINKING)) {
-		log_debug("%s: cursor %s, %sblinking", __func__,
-		    (mode & MODE_CURSOR) ? "on" : "off",
-		    (mode & MODE_BLINKING) ? "" : "not ");
-		if (~mode & MODE_CURSOR)
+	if (~mode & MODE_CURSOR) {
+		/* Cursor now off - set as invisible. */
+		if (changed & MODE_CURSOR)
 			tty_putcode(tty, TTYC_CIVIS);
-		else if (mode & MODE_BLINKING) {
-			tty_putcode(tty, TTYC_CNORM);
-			if (tty_term_has(tty->term, TTYC_CVVIS))
+	} else if ((changed & (MODE_CURSOR|MODE_BLINKING)) ||
+	    cstyle != tty->cstyle) {
+		/*
+		 * Cursor now on, blinking flag changed or style changed. Start
+		 * by setting the cursor to normal.
+		 */
+		tty_putcode(tty, TTYC_CNORM);
+		switch (cstyle) {
+		case SCREEN_CURSOR_DEFAULT:
+			/*
+			 * If the old style wasn't default, then reset it to
+			 * default.
+			 */
+			if (tty->cstyle != SCREEN_CURSOR_DEFAULT) {
+				if (tty_term_has(tty->term, TTYC_SE))
+					tty_putcode(tty, TTYC_SE);
+				else
+					tty_putcode1(tty, TTYC_SS, 0);
+			}
+
+			/* Set the cursor as very visible if necessary. */
+			if (mode & MODE_BLINKING)
 				tty_putcode(tty, TTYC_CVVIS);
-		} else
-			tty_putcode(tty, TTYC_CNORM);
+			break;
+		case SCREEN_CURSOR_BLOCK:
+			/*
+			 * Set style to either block blinking (1) or steady (2)
+			 * if supported, otherwise just check the blinking
+			 * flag.
+			 */
+			if (tty_term_has(tty->term, TTYC_SS)) {
+				if (mode & MODE_BLINKING)
+					tty_putcode1(tty, TTYC_SS, 1);
+				else
+					tty_putcode1(tty, TTYC_SS, 2);
+			} else if (mode & MODE_BLINKING)
+				tty_putcode(tty, TTYC_CVVIS);
+			break;
+		case SCREEN_CURSOR_UNDERLINE:
+			/*
+			 * Set style to either underline blinking (3) or steady
+			 * (4) if supported, otherwise just check the blinking
+			 * flag.
+			 */
+			if (tty_term_has(tty->term, TTYC_SS)) {
+				if (mode & MODE_BLINKING)
+					tty_putcode1(tty, TTYC_SS, 3);
+				else
+					tty_putcode1(tty, TTYC_SS, 4);
+			} else if (mode & MODE_BLINKING)
+				tty_putcode(tty, TTYC_CVVIS);
+			break;
+		case SCREEN_CURSOR_BAR:
+			/*
+			 * Set style to either bar blinking (5) or steady (6)
+			 * if supported, otherwise just check the blinking
+			 * flag.
+			 */
+			if (tty_term_has(tty->term, TTYC_SS)) {
+				if (mode & MODE_BLINKING)
+					tty_putcode1(tty, TTYC_SS, 5);
+				else
+					tty_putcode1(tty, TTYC_SS, 6);
+			} else if (mode & MODE_BLINKING)
+				tty_putcode(tty, TTYC_CVVIS);
+			break;
+		}
+		tty->cstyle = cstyle;
 	}
 
 	if ((changed & ALL_MOUSE_MODES) &&