From c5955d14cedf015fb2f5e6f25f1c042a075195b8 Mon Sep 17 00:00:00 2001
From: Benno Schulenberg <bensberg@telfort.nl>
Date: Mon, 10 Jun 2019 17:22:41 +0200
Subject: [PATCH] chars: speed up the determination of length and width for
 plain ASCII

---
 src/chars.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/chars.c b/src/chars.c
index 18fc92b2..c99206d8 100644
--- a/src/chars.c
+++ b/src/chars.c
@@ -207,7 +207,7 @@ char control_mbrep(const char *c, bool isdata)
 int length_of_char(const char *c, int *width)
 {
 #ifdef ENABLE_UTF8
-	if (use_utf8) {
+	if (use_utf8 && (signed char)*c < 0) {
 		wchar_t wc;
 		int charlen = mbtowc(&wc, c, MAXCHARLEN);