in hosts file lookups, use only first match for canonical name

the existing code clobbered the canonical name already discovered
every time another matching line was found, which will necessarily be
the case when a hostname has both IPv4 and v6 definitions.

patch by Wolf.

src/network/lookup_name.c

@@ -50,7 +50,7 @@ static int name_from_hosts(struct address buf[static MAXADDRS], char canon[stati
 {
 	char line[512];
 	size_t l = strlen(name);
-	int cnt = 0, badfam = 0;
+	int cnt = 0, badfam = 0, have_canon = 0;
 	unsigned char _buf[1032];
 	FILE _f, *f = __fopen_rb_ca("/etc/hosts", &_f, _buf, sizeof _buf);
 	if (!f) switch (errno) {
@@ -83,11 +83,16 @@ static int name_from_hosts(struct address buf[static MAXADDRS], char canon[stati
 			continue;
 		}
 
+		if (have_canon) continue;
+
 		/* Extract first name as canonical name */
 		for (; *p && isspace(*p); p++);
 		for (z=p; *z && !isspace(*z); z++);
 		*z = 0;
-		if (is_valid_hostname(p)) memcpy(canon, p, z-p+1);
+		if (is_valid_hostname(p)) {
+			have_canon = 1;
+			memcpy(canon, p, z-p+1);
+		}
 	}
 	__fclose_ca(f);
 	return cnt ? cnt : badfam;