Fix parseTarget for unix socket address without scheme (#1611)

resolver_conn_wrapper.go

@@ -37,20 +37,24 @@ type ccResolverWrapper struct {
 }
 
 // split2 returns the values from strings.SplitN(s, sep, 2).
-// If sep is not found, it returns "", s instead.
-func split2(s, sep string) (string, string) {
+// If sep is not found, it returns ("", s, false) instead.
+func split2(s, sep string) (string, string, bool) {
 	spl := strings.SplitN(s, sep, 2)
 	if len(spl) < 2 {
-		return "", s
+		return "", "", false
 	}
-	return spl[0], spl[1]
+	return spl[0], spl[1], true
 }
 
 // parseTarget splits target into a struct containing scheme, authority and
 // endpoint.
 func parseTarget(target string) (ret resolver.Target) {
-	ret.Scheme, ret.Endpoint = split2(target, "://")
-	ret.Authority, ret.Endpoint = split2(ret.Endpoint, "/")
+	var ok bool
+	ret.Scheme, ret.Endpoint, ok = split2(target, "://")
+	if !ok {
+		return resolver.Target{Endpoint: target}
+	}
+	ret.Authority, ret.Endpoint, _ = split2(ret.Endpoint, "/")
 	return ret
 }