From 85dd30306235ce01c9aeab4a95d68ca007841a79 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Fri, 12 Mar 2021 08:39:17 +0000
Subject: [PATCH] Fix so tmux correctly sends the cvvis (cursor very visible)
 capability rather than sending it and then immediately undoing it with cnorm.
 Also turn it off when the cursor shape is changed like xterm.

---
 usr.bin/tmux/screen.c |  6 ++++--
 usr.bin/tmux/tty.c    | 40 ++++++++++++++++++++++++++--------------
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/usr.bin/tmux/screen.c b/usr.bin/tmux/screen.c
index d5dfbffdcad..a01ddb33e17 100644
--- a/usr.bin/tmux/screen.c
+++ b/usr.bin/tmux/screen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen.c,v 1.69 2021/01/26 09:32:52 nicm Exp $ */
+/* $OpenBSD: screen.c,v 1.70 2021/03/12 08:39:17 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -154,8 +154,10 @@ screen_reset_tabs(struct screen *s)
 void
 screen_set_cursor_style(struct screen *s, u_int style)
 {
-	if (style <= 6)
+	if (style <= 6) {
 		s->cstyle = style;
+		s->mode &= ~MODE_BLINKING;
+	}
 }
 
 /* Set screen cursor colour. */
diff --git a/usr.bin/tmux/tty.c b/usr.bin/tmux/tty.c
index 6e7e97d9ab9..ba87484b588 100644
--- a/usr.bin/tmux/tty.c
+++ b/usr.bin/tmux/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.389 2021/02/17 07:18:36 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.390 2021/03/12 08:39:17 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -670,19 +670,10 @@ 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);
 
-	if (changed & MODE_BLINKING) {
-		if (tty_term_has(tty->term, TTYC_CVVIS))
-			tty_putcode(tty, TTYC_CVVIS);
-		else
-			tty_putcode(tty, TTYC_CNORM);
-		changed |= MODE_CURSOR;
-	}
-	if (changed & MODE_CURSOR) {
-		if (mode & MODE_CURSOR)
-			tty_putcode(tty, TTYC_CNORM);
-		else
-			tty_putcode(tty, TTYC_CIVIS);
-	}
+	/*
+	 * 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))
@@ -691,7 +682,28 @@ tty_update_mode(struct tty *tty, int mode, struct screen *s)
 				tty_putcode1(tty, TTYC_SS, s->cstyle);
 		}
 		tty->cstyle = s->cstyle;
+		changed |= (MODE_CURSOR|MODE_BLINKING);
 	}
+
+	/*
+	 * 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)
+			tty_putcode(tty, TTYC_CIVIS);
+		else if (mode & MODE_BLINKING) {
+			tty_putcode(tty, TTYC_CNORM);
+			if (tty_term_has(tty->term, TTYC_CVVIS))
+				tty_putcode(tty, TTYC_CVVIS);
+		} else
+			tty_putcode(tty, TTYC_CNORM);
+	}
+
 	if ((changed & ALL_MOUSE_MODES) &&
 	    tty_term_has(tty->term, TTYC_KMOUS)) {
 		/*
-- 
2.20.1