From 487fcb4bffe2982b70d476db9d5759dbc3a025a1 Mon Sep 17 00:00:00 2001
From: Eirikr Hinngart
 <151315375+Oichkatzelesfrettschen@users.noreply.github.com>
Date: Sat, 17 May 2025 00:53:05 -0700
Subject: [PATCH] Handle invalid hex escapes in seq

---
 usr.bin/seq/seq.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/usr.bin/seq/seq.c b/usr.bin/seq/seq.c
index fc5a15ccd..bb00a339b 100644
--- a/usr.bin/seq/seq.c
+++ b/usr.bin/seq/seq.c
@@ -350,8 +350,13 @@ unescape(char *orig)
 			*orig = c;
 			--cp;
 			continue;
-		case 'x':	/* hexidecimal number */
+		case 'x':	/* hexadecimal number */
 			cp++;	/* skip 'x' */
+			if (!isxdigit((unsigned char)*cp)) {
+			        --cp;
+			/* keep the backslash, treat 'x' literally */
+			        continue;
+			}
 			for (i = 0, c = 0;
 			     isxdigit((unsigned char)*cp) && i < 2;
 			     i++, cp++) {