channeldb: attach DB to channel in FetchHistoricalChannel

channeldb/db.go

@@ -1299,6 +1299,8 @@ func (d *DB) FetchHistoricalChannel(outPoint *wire.OutPoint) (*OpenChannel, erro
 		}
 
 		channel, err = fetchOpenChannel(chanBucket, outPoint)
+
+		channel.Db = d
 		return err
 	}, func() {
 		channel = nil

channeldb/db_test.go

@@ -717,9 +717,10 @@ func TestFetchHistoricalChannel(t *testing.T) {
 		t.Fatalf("unexepected error getting channel: %v", err)
 	}
 
-	// Set the db on our channel to nil so that we can check that all other
+	// FetchHistoricalChannel will attach the cdb to channel.Db, we set it
-	// fields on the channel equal those on the historical channel.
+	// here so that we can check that all other fields on the channel equal
-	channel.Db = nil
+	// those on the historical channel.
+	channel.Db = cdb
 
 	if !reflect.DeepEqual(histChannel, channel) {
 		t.Fatalf("expected: %v, got: %v", channel, histChannel)