Revert previous, there were some unintended beviour changes.

1 files changed, 27 insertions, 3 deletions

diff --git a/bin/ed/re.c b/bin/ed/re.c
index 413011da63f..c81a3ee0518 100644
--- a/bin/ed/re.c
+++ b/bin/ed/re.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: re.c,v 1.18 2018/06/18 17:08:20 martijn Exp $	*/
+/*	$OpenBSD: re.c,v 1.19 2018/06/19 12:36:18 martijn Exp $	*/
 /*	$NetBSD: re.c,v 1.14 1995/03/21 09:04:48 cgd Exp $	*/
 
 /* re.c: This file contains the regular expression interface routines for
@@ -94,10 +94,16 @@ extract_pattern(int delimiter)
 	char *nd;
 	int len;
 
-	for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++) {
+	for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++)
 		switch (*nd) {
 		default:
 			break;
+		case '[':
+			if ((nd = parse_char_class(++nd)) == NULL) {
+				seterrmsg("unbalanced brackets ([])");
+				return NULL;
+			}
+			break;
 		case '\\':
 			if (*++nd == '\n') {
 				seterrmsg("trailing backslash (\\)");
@@ -105,7 +111,6 @@ extract_pattern(int delimiter)
 			}
 			break;
 		}
-	}
 	len = nd - ibufp;
 	REALLOC(lhbuf, lhbufsz, len + 1, NULL);
 	memcpy(lhbuf, ibufp, len);
@@ -113,3 +118,22 @@ extract_pattern(int delimiter)
 	ibufp = nd;
 	return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf;
 }
+
+
+/* parse_char_class: expand a POSIX character class */
+static char *
+parse_char_class(char *s)
+{
+	int c, d;
+
+	if (*s == '^')
+		s++;
+	if (*s == ']')
+		s++;
+	for (; *s != ']' && *s != '\n'; s++)
+		if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
+			for (s++, c = *++s; *s != ']' || c != d; s++)
+				if ((c = *s) == '\n')
+					return NULL;
+	return  (*s == ']') ? s : NULL;
+}