From f9dc374ea01c2921ec3bd1214f292a7036d069ae Mon Sep 17 00:00:00 2001
From: noname <noname@inventati.org>
Date: Wed, 23 Apr 2014 00:26:07 +0400
Subject: Fix techo handling of control and multibyte characters.

techo compares signed char to '\x20'. Any character with code less then
'\x20' is treated as control character.  This way characters with MSB
set to 1 are considered control characters too.

Also this patch makes techo display DEL character as ^?.

To reprocuce the bug, enable echo mode using printf '\e[12l',
then type DEL character or any non-ASCII character.
---
 st.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'st.c')

diff --git a/st.c b/st.c
index aba034f..b66791a 100644
--- a/st.c
+++ b/st.c
@@ -2308,9 +2308,9 @@ techo(char *buf, int len) {
 	for(; len > 0; buf++, len--) {
 		char c = *buf;
 
-		if(c < '\x20') { /* control code */
+		if(c < 0x20 || c == 0177) { /* control code */
 			if(c != '\n' && c != '\r' && c != '\t') {
-				c |= '\x40';
+				c ^= '\x40';
 				tputc("^", 1);
 			}
 			tputc(&c, 1);
-- 
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