backout VIS_HEX. guenther@ points out that the C89 \xff encoding

idiotically accepts more then two hex digits following the \x, even
on platforms where a char has 8 bits. It is therefore dangerous to have
an almost-bit-not-quite compatible format in vis(3).

The VIS_ALL (encode all characters) option introduced in the same commit
remains.

3 files changed, 10 insertions, 73 deletions

diff --git a/lib/libc/gen/unvis.c b/lib/libc/gen/unvis.c
index 29c3d0a7913..d00d527b5aa 100644
--- a/lib/libc/gen/unvis.c
+++ b/lib/libc/gen/unvis.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: unvis.c,v 1.13 2010/08/21 18:59:15 djm Exp $ */
+/*	$OpenBSD: unvis.c,v 1.14 2010/08/24 23:49:06 djm Exp $ */
 /*-
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -42,25 +42,8 @@
 #define	S_CTRL		4	/* control char started (^) */
 #define	S_OCTAL2	5	/* octal digit 2 */
 #define	S_OCTAL3	6	/* octal digit 3 */
-#define	S_HEX1		7	/* hex digit 1 */
-#define	S_HEX2		8	/* hex digit 2 */
 
 #define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
-#define	ishex(c)	((((u_char)(c)) >= '0' && ((u_char)(c)) <= '9') || \
-			 (((u_char)(c)) >= 'a' && ((u_char)(c)) <= 'f') || \
-			 (((u_char)(c)) >= 'A' && ((u_char)(c)) <= 'F'))
-
-static u_int
-dehex(u_int c)
-{
-	if (c >= '0' && c <= '9')
-		return c - '0';
-	if (c >= 'a' && c <= 'f')
-		return 10 + c - 'a';
-	if (c >= 'A' && c <= 'F')
-		return 10 + c - 'A';
-	return 0;
-}
 
 /*
  * unvis - decode characters previously encoded by vis
@@ -70,8 +53,7 @@ unvis(char *cp, char c, int *astate, int flag)
 {
 
 	if (flag & UNVIS_END) {
-		if (*astate == S_OCTAL2 || *astate == S_OCTAL3 ||
-		    *astate == S_HEX1 || *astate == S_HEX2) {
+		if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
 			*astate = S_GROUND;
 			return (UNVIS_VALID);
 		} 
@@ -95,9 +77,6 @@ unvis(char *cp, char c, int *astate, int flag)
 			*cp = c;
 			*astate = S_GROUND;
 			return (UNVIS_VALID);
-		case 'x':
-			*astate = S_HEX1;
-			return (0);
 		case '0': case '1': case '2': case '3':
 		case '4': case '5': case '6': case '7':
 			*cp = (c - '0');
@@ -212,32 +191,6 @@ unvis(char *cp, char c, int *astate, int flag)
 		 */
 		return (UNVIS_VALIDPUSH);
 
-	case S_HEX1:	/* first possible hex digit */
-		if (ishex(c)) {
-			/* 
-			 * yes - and maybe a second
-			 */
-			*cp = dehex(c);
-			*astate = S_HEX2;	
-			return (0);
-		} 
-		/* 
-		 * no - done with current sequence, push back passed char 
-		 */
-		*astate = S_GROUND;
-		return (UNVIS_VALIDPUSH);
-
-	case S_HEX2:	/* second possible hex digit */
-		*astate = S_GROUND;
-		if (ishex(c)) {
-			*cp = ((u_int)*cp << 4) + dehex(c);
-			return (UNVIS_VALID);
-		}
-		/*
-		 * we were done, push back passed char
-		 */
-		return (UNVIS_VALIDPUSH);
-
 	default:	
 		/* 
 		 * decoder in unknown state - (probably uninitialized) 
diff --git a/lib/libc/gen/vis.3 b/lib/libc/gen/vis.3
index ce63c2c49f7..c3289fed6d7 100644
--- a/lib/libc/gen/vis.3
+++ b/lib/libc/gen/vis.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: vis.3,v 1.25 2010/08/21 18:59:15 djm Exp $
+.\"	$OpenBSD: vis.3,v 1.26 2010/08/24 23:49:06 djm Exp $
 .\"
 .\" Copyright (c) 1989, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -27,7 +27,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: August 21 2010 $
+.Dd $Mdocdate: August 24 2010 $
 .Dt VIS 3
 .Os
 .Sh NAME
@@ -280,13 +280,6 @@ If
 .Fa nextc
 is an octal digit, the latter representation is used to
 avoid ambiguity.
-.It Dv VIS_HEX
-Use a two digit hexadecimal sequence.
-The form is
-.Ql \exdd
-where
-.Ar d
-represents a hexadecimal digit.
 .It Dv VIS_OCTAL
 Use a three digit octal sequence.
 The form is
diff --git a/lib/libc/gen/vis.c b/lib/libc/gen/vis.c
index 51407e6a7da..83227d96705 100644
--- a/lib/libc/gen/vis.c
+++ b/lib/libc/gen/vis.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vis.c,v 1.20 2010/08/21 18:59:15 djm Exp $ */
+/*	$OpenBSD: vis.c,v 1.21 2010/08/24 23:49:06 djm Exp $ */
 /*-
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -46,8 +46,6 @@
 		(c) == '\007' || (c) == '\r' ||				\
 		isgraph((u_char)(c)))))
 
-static const char hexdigits[] = "0123456789abcdef";
-
 /*
  * vis - visually encode characters
  */
@@ -106,19 +104,12 @@ vis(char *dst, int c, int flag, int nextc)
 			goto done;
 		}
 	}
-	if (((c & 0177) == ' ') || (flag & (VIS_OCTAL|VIS_HEX)) ||
+	if (((c & 0177) == ' ') || (flag & VIS_OCTAL) ||
 	    ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) {
-		if ((flag & VIS_HEX) != 0) {
-			*dst++ = '\\';
-			*dst++ = 'x';
-			*dst++ = hexdigits[((u_char)c >> 4 & 0xf)];
-			*dst++ = hexdigits[((u_char)c & 0xf)];
-		} else {
-			*dst++ = '\\';
-			*dst++ = ((u_char)c >> 6 & 07) + '0';
-			*dst++ = ((u_char)c >> 3 & 07) + '0';
-			*dst++ = ((u_char)c & 07) + '0';
-		}
+		*dst++ = '\\';
+		*dst++ = ((u_char)c >> 6 & 07) + '0';
+		*dst++ = ((u_char)c >> 3 & 07) + '0';
+		*dst++ = ((u_char)c & 07) + '0';
 		goto done;
 	}
 	if ((flag & VIS_NOSLASH) == 0)