From a7d7e29300acade90f2025f0b85fa5eae06edb24 Mon Sep 17 00:00:00 2001
From: "Roberto E. Vargas Caballero" <k0ga@shike2.com>
Date: Wed, 26 Sep 2012 20:53:46 +0200
Subject: [PATCH] Ignore all control characters not handled

Taken from vt100 programmer manual:

	Control characters have values of \000 - \037, and \177. The control
	characters recognized by the VT100 are shown in Table 3-10. All
	other control codes cause no action to be taken.

We have to take attention when we are using alternate charset, because in
this cases they are not used as control characters.
---
 st.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)
---
 st.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/st.c b/st.c
index a64b84d..515dfb1 100644
--- a/st.c
+++ b/st.c
@@ -1663,7 +1663,7 @@ tputtab(bool forward) {
 
 void
 tputc(char *c, int len) {
-	char ascii = *c;
+	uchar ascii = *c;
 
 	if(iofd != -1)
 		write(iofd, c, len);
@@ -1792,8 +1792,6 @@ tputc(char *c, int len) {
 		if(sel.bx != -1 && BETWEEN(term.c.y, sel.by, sel.ey))
 			sel.bx = -1;
 		switch(ascii) {
-		case '\0': /* padding character, do nothing */
-			break;
 		case '\t':
 			tputtab(1);
 			break;
@@ -1818,13 +1816,15 @@ tputc(char *c, int len) {
 			term.esc = ESC_START;
 			break;
 		default:
-			if(IS_SET(MODE_WRAP) && term.c.state & CURSOR_WRAPNEXT)
-				tnewline(1); /* always go to first col */
-			tsetchar(c);
-			if(term.c.x+1 < term.col)
-				tmoveto(term.c.x+1, term.c.y);
-			else
-				term.c.state |= CURSOR_WRAPNEXT;
+			if(ascii >= '\020' || term.c.attr.mode & ATTR_GFX) {
+				if(IS_SET(MODE_WRAP) && term.c.state & CURSOR_WRAPNEXT)
+					tnewline(1); /* always go to first col */
+				tsetchar(c);
+				if(term.c.x+1 < term.col)
+					tmoveto(term.c.x+1, term.c.y);
+				else
+					term.c.state |= CURSOR_WRAPNEXT;
+			}
 		}
 	}
 }