fix err; add test; fix bug

clientconn.go

@@ -591,9 +591,16 @@ func (cc *ClientConn) updateResolverState(s resolver.State, err error) error {
 		} else {
 			ret = balancer.ErrBadResolverState
 			if cc.balancerWrapper == nil {
-				cc.blockingpicker.updatePicker(base.NewErrPicker(status.Errorf(codes.Unavailable, "error parsing service config: %v", s.ServiceConfig.Err)))
+				var err error
+				if s.ServiceConfig.Err != nil {
+					err = status.Errorf(codes.Unavailable, "error parsing service config: %v", s.ServiceConfig.Err)
+				} else {
+					err = status.Errorf(codes.Unavailable, "illegal service config type: %T", s.ServiceConfig.Config)
+				}
+				cc.blockingpicker.updatePicker(base.NewErrPicker(err))
 				cc.csMgr.updateState(connectivity.TransientFailure)
 				cc.mu.Unlock()
+				cc.firstResolveEvent.Fire()
 				return ret
 			}
 		}

resolver_conn_wrapper_test.go

@@ -19,14 +19,18 @@
 package grpc
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"net"
+	"strings"
 	"testing"
 	"time"
 
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/resolver/manual"
+	"google.golang.org/grpc/status"
 )
 
 func (s) TestParseTarget(t *testing.T) {
@@ -197,3 +201,25 @@ func (s) TestServiceConfigErrorPolling(t *testing.T) {
 		go r.CC.UpdateState(resolver.State{})
 	})
 }
+
+func (s) TestServiceConfigErrorRPC(t *testing.T) {
+	r, rcleanup := manual.GenerateAndRegisterManualResolver()
+	defer rcleanup()
+
+	cc, err := Dial(r.Scheme()+":///test.server", WithInsecure())
+	if err != nil {
+		t.Fatalf("Dial(_, _) = _, %v; want _, nil", err)
+	}
+	defer cc.Close()
+	badsc := r.CC.ParseServiceConfig("bad config")
+	r.UpdateState(resolver.State{ServiceConfig: badsc})
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	var dummy int
+	const wantMsg = "error parsing service config"
+	const wantCode = codes.Unavailable
+	if err := cc.Invoke(ctx, "/foo/bar", &dummy, &dummy); status.Code(err) != wantCode || !strings.Contains(status.Convert(err).Message(), wantMsg) {
+		t.Fatalf("cc.Invoke(_, _, _, _) = %v; want status.Code()==%v, status.Message() contains %q", err, wantCode, wantMsg)
+	}
+}