--- strtonum.c.orig	2006-03-14 21:53:03.000000000 +0200
+++ strtonum.c	2012-03-12 13:05:40.000000000 +0200
@@ -24,45 +24,51 @@ __FBSDID("$FreeBSD: src/lib/libc/stdlib/
 #include <limits.h>
 #include <stdlib.h>
 
-#define INVALID 	1
-#define TOOSMALL 	2
-#define TOOLARGE 	3
+#define INVALID 	0
+#define TOOSMALL 	1
+#define TOOLARGE 	2
 
 long long
 strtonum(const char *numstr, long long minval, long long maxval,
     const char **errstrp)
 {
-	long long ll = 0;
-	char *ep;
-	int error = 0;
-	struct errval {
-		const char *errstr;
-		int err;
-	} ev[4] = {
-		{ NULL,		0 },
-		{ "invalid",	EINVAL },
-		{ "too small",	ERANGE },
-		{ "too large",	ERANGE },
+	static const struct {
+		const char	*errstr;
+		int		errnum;
+	} ev[] = {
+		[INVALID]	= { "invalid",		EINVAL },
+		[TOOSMALL]	= { "too small",	ERANGE },
+		[TOOLARGE]	= { "too large",	ERANGE }
 	};
 
-	ev[0].err = errno;
-	errno = 0;
+	int error;
+
 	if (minval > maxval)
 		error = INVALID;
 	else {
+		long long ll;
+		char *ep;
+		int errno_save;
+
+		errno_save = errno;
+		errno = 0;
 		ll = strtoll(numstr, &ep, 10);
-		if (errno == EINVAL || numstr == ep || *ep != '\0')
+		error = errno;
+		if (error == EINVAL || numstr == ep || *ep != '\0')
 			error = INVALID;
-		else if ((ll == LLONG_MIN && errno == ERANGE) || ll < minval)
+		else if ((ll == LLONG_MIN && error == ERANGE) || ll < minval)
 			error = TOOSMALL;
-		else if ((ll == LLONG_MAX && errno == ERANGE) || ll > maxval)
+		else if ((ll == LLONG_MAX && error == ERANGE) || ll > maxval)
 			error = TOOLARGE;
+		else {
+			errno = errno_save;
+			if (errstrp != NULL)
+				*errstrp = NULL;
+			return (ll);
+		}
 	}
 	if (errstrp != NULL)
 		*errstrp = ev[error].errstr;
-	errno = ev[error].err;
-	if (error)
-		ll = 0;
-
-	return (ll);
+	errno = ev[error].errnum;
+	return (0);
 }