From bda0a3d1b7db27708d02d0ff537d5f7138dad6d7 Mon Sep 17 00:00:00 2001
From: Witold Filipczyk <witekfl@poczta.onet.pl>
Date: Thu, 20 Jul 2023 10:10:07 +0200
Subject: [PATCH] [xterm] Assume that if WAYLAND_DISPLAY or DISPLAY is set it
 must be xterm

---
 src/osdep/osdep.c | 52 ++++++++---------------------------------------
 1 file changed, 8 insertions(+), 44 deletions(-)

diff --git a/src/osdep/osdep.c b/src/osdep/osdep.c
index 3b1024c4e..3accda827 100644
--- a/src/osdep/osdep.c
+++ b/src/osdep/osdep.c
@@ -308,62 +308,26 @@ is_gnuscreen(void)
 
 #if defined(CONFIG_OS_UNIX) || defined(CONFIG_OS_WIN32)
 
-static int
-check_more_envs(void)
-{
-	const char *envs[] = { "WINDOWID",
-		"KONSOLE_DCOP_SESSION",
-		"GNOME_TERMINAL_SERVICE",
-		"XDG_SESSION_DESKTOP",
-		NULL
-	};
-	const char **v;
-
-	for (v = envs; *v; ++v)
-	{
-		char *value = getenv(*v);
-
-		if (value && *value) {
-			return 1;
-		}
-	}
-
-	return 0;
-}
-
 int
 is_xterm(void)
 {
 	static int xt = -1;
 
 	if (xt == -1) {
-		/* Paraphrased from debian bug 228977:
-		 *
-		 * It is not enough to simply check the DISPLAY env variable,
-		 * as it is pretty legal to have a DISPLAY set. While these
-		 * days this practice is pretty uncommon, it still makes sense
-		 * sometimes, especially for people who prefer the text mode
-		 * for some reason. Only relying on DISPLAY will results in bad
-		 * codes being written to the terminal.
-		 *
-		 * Any real xterm derivative sets WINDOWID as well.
-		 * Unfortunately, konsole is an exception, and it needs to be
-		 * checked for separately.
-		 *
-		 * FIXME: The code below still fails to detect some terminals
-		 * that do support a title (like the popular PuTTY ssh client).
-		 * In general, proper xterm detection is a nightmarish task...
-		 *
-		 * -- Adam Borowski <kilobyte@mimuw.edu.pl> */
-
 		char *term = getenv("TERM");
 
 		if (term && !strncmp("xterm", term, 5)) {
 			xt = 1;
 		} else {
-			char *display = getenv("DISPLAY");
+			char *wayland = getenv("WAYLAND_DISPLAY");
 
-			xt = (display && *display && check_more_envs());
+			if (wayland && *wayland) {
+				xt = 1;
+			} else {
+				char *display = getenv("DISPLAY");
+
+				xt = display && *display;
+			}
 		}
 	}