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(-)
diff --git a/st.c b/st.c
index 019f53c..b6cb01c 100644
--- a/st.c
+++ b/st.c
@@ -2316,9 +2316,9 @@ techo(char *buf, int len) {
for(; len > 0; buf++, len--) {
char c = *buf;
- if(c < '\x20') { /* control code */
+ if(c < 0x20u || c == 0177) { /* control code */
if(c != '\n' && c != '\r' && c != '\t') {
- c |= '\x40';
+ c ^= '\x40';
tputc("^", 1);
}
tputc(&c, 1);
--
1.8.4
