From 4872811ba78bd68c71d40b820065c093ed427970 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Fri, 8 Sep 2023 06:52:31 +0000
Subject: [PATCH 1/2] Use DECSLRM and DECFRA only at level 4 rather than
 checking the terminal id.

---
 format.c   |  5 ++---
 tty-keys.c | 26 +++++++++++++-------------
 2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/format.c b/format.c
index 6e9094c2..7979e970 100644
--- a/format.c
+++ b/format.c
@@ -1126,7 +1126,6 @@ format_cb_mouse_word(struct format_tree *ft)
 	struct window_pane	*wp;
 	struct grid		*gd;
 	u_int			 x, y;
-	char			*s;
 
 	if (!ft->m.valid)
 		return (NULL);
@@ -1139,7 +1138,7 @@ format_cb_mouse_word(struct format_tree *ft)
 	if (!TAILQ_EMPTY(&wp->modes)) {
 		if (TAILQ_FIRST(&wp->modes)->mode == &window_copy_mode ||
 		    TAILQ_FIRST(&wp->modes)->mode == &window_view_mode)
-			return (s = window_copy_get_word(wp, x, y));
+			return (window_copy_get_word(wp, x, y));
 		return (NULL);
 	}
 	gd = wp->base.grid;
@@ -4185,7 +4184,7 @@ static char *
 format_loop_clients(struct format_expand_state *es, const char *fmt)
 {
 	struct format_tree		*ft = es->ft;
-	struct client			*c = ft->client;
+	struct client			*c;
 	struct cmdq_item		*item = ft->item;
 	struct format_tree		*nft;
 	struct format_expand_state	 next;
diff --git a/tty-keys.c b/tty-keys.c
index 3a8b779e..3ad80c3d 100644
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -1315,15 +1315,21 @@ tty_keys_device_attributes(struct tty *tty, const char *buf, size_t len,
 	}
 
 	/*
-	 * Add terminal features. Technically, VT420 and VT525 do not support
-	 * SIXEL, but some modern terminals report it anyway so we accept it
-	 * here too.
+	 * Add terminal features. Hardware level 5 does not offer SIXEL but
+	 * some terminal emulators report it anyway and it does not harm
+	 * to check it here.
+	 *
+	 * DECSLRM and DECFRA should be supported by level 5 as well as level
+	 * 4, but VTE has rather ruined it by advertising level 5 despite not
+	 * supporting them.
 	 */
 	switch (p[0]) {
-	case 62: /* VT220 */
-	case 63: /* VT320 */
-	case 64: /* VT420 */
-	case 65: /* VT525 */
+	case 64: /* level 4 */
+		tty_add_features(features, "margins,rectfill", ",");
+		/* FALLTHROUGH */
+	case 62: /* level 2 */
+	case 63: /* level 3 */
+	case 65: /* level 5 */
 		for (i = 1; i < n; i++) {
 			log_debug("%s: DA feature: %d", c->name, p[i]);
 			if (p[i] == 4)
@@ -1395,12 +1401,6 @@ tty_keys_device_attributes2(struct tty *tty, const char *buf, size_t len,
 
 	/* Add terminal features. */
 	switch (p[0]) {
-	case 41: /* VT420 */
-	case 61: /* VT510 */
-	case 64: /* VT520 */
-	case 65: /* VT525 */
-		tty_add_features(features, "margins,rectfill", ",");
-		break;
 	case 'M': /* mintty */
 		tty_default_features(features, "mintty", 0);
 		break;

From c02bc4dbe9692fb8f698509a35c3abccf895f263 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Fri, 8 Sep 2023 07:05:06 +0000
Subject: [PATCH 2/2] On second thoughts, do check DA2 for DECFRA and DECSLRM
 since that will catch terminals that say they are VT520 even if we can't use
 DA1 (because of VTE).

---
 tty-keys.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tty-keys.c b/tty-keys.c
index 3ad80c3d..ef80abc4 100644
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -1399,8 +1399,17 @@ tty_keys_device_attributes2(struct tty *tty, const char *buf, size_t len,
 			break;
 	}
 
-	/* Add terminal features. */
+	/*
+	 * Add terminal features. We add DECSLRM and DECFRA for some
+	 * identification codes here, notably 64 will catch VT520, even though
+	 * we can't use level 5 from DA because of VTE.
+	 */
 	switch (p[0]) {
+	case 41: /* VT420 */
+	case 61: /* VT510 */
+	case 64: /* VT520 */
+		tty_add_features(features, "margins,rectfill", ",");
+		break;
 	case 'M': /* mintty */
 		tty_default_features(features, "mintty", 0);
 		break;