From 6f0254e6a88ee5e66c8ea5d8723c7adfb7181585 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Thu, 21 Mar 2024 11:47:55 +0000
Subject: [PATCH] Look for feature code 21 for DECSLRM and 28 for DECFRA in the
 device attributes and also accept level 1 (there is no hardware with this but
 some emulators may use it). Pointed out by James Holderness.

---
 tty-keys.c | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff --git a/tty-keys.c b/tty-keys.c
index ef80abc4..9f8ff67c 100644
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -1314,26 +1314,21 @@ tty_keys_device_attributes(struct tty *tty, const char *buf, size_t len,
 			break;
 	}
 
-	/*
-	 * 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.
-	 */
+	/* Add terminal features. */
 	switch (p[0]) {
-	case 64: /* level 4 */
-		tty_add_features(features, "margins,rectfill", ",");
-		/* FALLTHROUGH */
+	case 61: /* level 1 */
 	case 62: /* level 2 */
 	case 63: /* level 3 */
+	case 64: /* level 4 */
 	case 65: /* level 5 */
 		for (i = 1; i < n; i++) {
 			log_debug("%s: DA feature: %d", c->name, p[i]);
 			if (p[i] == 4)
 				tty_add_features(features, "sixel", ",");
+			if (p[i] == 21)
+				tty_add_features(features, "margins", ",");
+			if (p[i] == 28)
+				tty_add_features(features, "rectfill", ",");
 		}
 		break;
 	}
@@ -1405,11 +1400,6 @@ tty_keys_device_attributes2(struct tty *tty, const char *buf, size_t len,
 	 * 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;