Index: head/lib/libc/regex/regcomp.c
===================================================================
--- head/lib/libc/regex/regcomp.c
+++ head/lib/libc/regex/regcomp.c
@@ -1841,21 +1841,29 @@
 {
 	int ch;
 	int mindex;
+	int cmin, cmax;
 
+	/*
+	 * For UTF-8 we process only the first 128 characters corresponding to
+	 * the POSIX locale.
+	 */
+	cmin = MB_CUR_MAX == 1 ? CHAR_MIN : 0;
+	cmax = MB_CUR_MAX == 1 ? CHAR_MAX : 127;
+
 	/* Avoid making errors worse */
 	if (p->error != 0)
 		return;
 
-	g->charjump = (int*) malloc((NC + 1) * sizeof(int));
+	g->charjump = (int *)malloc((cmax - cmin + 1) * sizeof(int));
 	if (g->charjump == NULL)	/* Not a fatal error */
 		return;
 	/* Adjust for signed chars, if necessary */
-	g->charjump = &g->charjump[-(CHAR_MIN)];
+	g->charjump = &g->charjump[-(cmin)];
 
 	/* If the character does not exist in the pattern, the jump
 	 * is equal to the number of characters in the pattern.
 	 */
-	for (ch = CHAR_MIN; ch < (CHAR_MAX + 1); ch++)
+	for (ch = cmin; ch < cmax + 1; ch++)
 		g->charjump[ch] = g->mlen;
 
 	/* If the character does exist, compute the jump that would
Index: head/lib/libc/regex/regex2.h
===================================================================
--- head/lib/libc/regex/regex2.h
+++ head/lib/libc/regex/regex2.h
@@ -113,7 +113,7 @@
 	wint_t		max;
 } crange;
 typedef struct {
-	unsigned char	bmp[NC / 8];
+	unsigned char	bmp[NC_MAX / 8];
 	wctype_t	*types;
 	unsigned int	ntypes;
 	wint_t		*wides;
@@ -133,9 +133,14 @@
 	if (ch < NC)
 		return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
 		    cs->invert);
-	for (i = 0; i < cs->nwides; i++)
-		if (ch == cs->wides[i])
+	for (i = 0; i < cs->nwides; i++) {
+		if (cs->icase) {
+			if (ch == towlower(cs->wides[i]) ||
+			    ch == towupper(cs->wides[i]))
+				return (!cs->invert);
+		} else if (ch == cs->wides[i])
 			return (!cs->invert);
+	}
 	for (i = 0; i < cs->nranges; i++)
 		if (cs->ranges[i].min <= ch && ch <= cs->ranges[i].max)
 			return (!cs->invert);
Index: head/lib/libc/regex/utils.h
===================================================================
--- head/lib/libc/regex/utils.h
+++ head/lib/libc/regex/utils.h
@@ -39,7 +39,9 @@
 /* utility definitions */
 #define	DUPMAX		_POSIX2_RE_DUP_MAX	/* xxx is this right? */
 #define	INFINITY	(DUPMAX + 1)
-#define	NC		(CHAR_MAX - CHAR_MIN + 1)
+
+#define	NC_MAX		(CHAR_MAX - CHAR_MIN + 1)
+#define	NC		((MB_CUR_MAX) == 1 ? (NC_MAX) : (128))
 typedef unsigned char uch;
 
 /* switch off assertions (if not already off) if no REDEBUG */
Index: head/lib/libc/tests/regex/multibyte.sh
===================================================================
--- head/lib/libc/tests/regex/multibyte.sh
+++ head/lib/libc/tests/regex/multibyte.sh
@@ -1,11 +1,11 @@
 # $FreeBSD$
 
-atf_test_case multibyte
-multibyte_head()
+atf_test_case bmpat
+bmpat_head()
 {
 	atf_set "descr" "Check matching multibyte characters (PR153502)"
 }
-multibyte_body()
+bmpat_body()
 {
 	export LC_CTYPE="C.UTF-8"
 
@@ -29,7 +29,25 @@
 	    sed -ne '/.a./p'
 }
 
+atf_test_case icase
+icase_head()
+{
+	atf_set "descr" "Check case-insensitive matching for characters 128-255"
+}
+icase_body()
+{
+	export LC_CTYPE="C.UTF-8"
+
+	a=$(printf '\302\265\n')	# U+00B5
+	b=$(printf '\316\234\n')	# U+039C
+	c=$(printf '\316\274\n')	# U+03BC
+
+	echo $b | atf_check -o "inline:$b\n" sed -ne "/$a/Ip"
+	echo $c | atf_check -o "inline:$c\n" sed -ne "/$a/Ip"
+}
+
 atf_init_test_cases()
 {
-	atf_add_test_case multibyte
+	atf_add_test_case bmpat
+	atf_add_test_case icase
 }