Merge pull request #3509 from ipfs/fix/namesys/dht-cache-panic

namesys: fix case where there is no cache

namesys/namesys.go

@@ -107,6 +107,16 @@ func (ns *mpns) PublishWithEOL(ctx context.Context, name ci.PrivKey, value path.
 }
 
 func (ns *mpns) addToDHTCache(key ci.PrivKey, value path.Path, eol time.Time) {
+	rr, ok := ns.resolvers["dht"].(*routingResolver)
+	if !ok {
+		// should never happen, purely for sanity
+		log.Panicf("unexpected type %T as DHT resolver.", ns.resolvers["dht"])
+	}
+	if rr.cache == nil {
+		// resolver has no caching
+		return
+	}
+
 	var err error
 	value, err = path.ParsePath(value.String())
 	if err != nil {
@@ -120,11 +130,6 @@ func (ns *mpns) addToDHTCache(key ci.PrivKey, value path.Path, eol time.Time) {
 		return
 	}
 
-	rr, ok := ns.resolvers["dht"].(*routingResolver)
-	if !ok {
-		// should never happen, purely for sanity
-		log.Panicf("unexpected type %T as DHT resolver.", ns.resolvers["dht"])
-	}
 	if time.Now().Add(DefaultResolverCacheTTL).Before(eol) {
 		eol = time.Now().Add(DefaultResolverCacheTTL)
 	}

namesys/namesys_test.go

@@ -7,6 +7,11 @@ import (
 	context "context"
 
 	path "github.com/ipfs/go-ipfs/path"
+	offroute "github.com/ipfs/go-ipfs/routing/offline"
+	"github.com/ipfs/go-ipfs/unixfs"
+
+	ds "gx/ipfs/QmRWDav6mzWseLWeYfVd5fvUKiVe9xNH29YfMF438fG364/go-datastore"
+	ci "gx/ipfs/QmfWDLQjGjVe4fr5CoztYW2DYYjRysMJrFe1RCsXLPTf46/go-libp2p-crypto"
 )
 
 type mockResolver struct {
@@ -69,3 +74,19 @@ func TestNamesysResolution(t *testing.T) {
 	testResolution(t, r, "/ipns/QmY3hE8xgFCjGcz6PHgnvJz5HZi1BaKRfPkn1ghZUcYMjD", 2, "/ipns/QmbCMUZw6JFeZ7Wp9jkzbye3Fzp2GGcPgC3nmeUjfVF87n", ErrResolveRecursion)
 	testResolution(t, r, "/ipns/QmY3hE8xgFCjGcz6PHgnvJz5HZi1BaKRfPkn1ghZUcYMjD", 3, "/ipns/QmatmE9msSfkKxoffpHwNLNKgwZG8eT9Bud6YoPab52vpy", ErrResolveRecursion)
 }
+
+func TestPublishWithCache0(t *testing.T) {
+	dst := ds.NewMapDatastore()
+	priv, _, err := ci.GenerateKeyPair(ci.RSA, 1024)
+	if err != nil {
+		t.Fatal(err)
+	}
+	routing := offroute.NewOfflineRouter(dst, priv)
+
+	nsys := NewNameSystem(routing, dst, 0)
+	p, err := path.ParsePath(unixfs.EmptyDirNode().Cid().String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	nsys.Publish(context.Background(), priv, p)
+}