Re-introduce deprecated method of requesting messages

During the move to waku/1 we removed handing of a deprecated format.
aa7f591587 (diff-ea5e44cf3db4a12b3a2a246c7fa39602R290)
Turns out that no client is using the new format and the only live
client is using the deprecated format.
This commit re-introduces the functionality.

VERSION

@@ -1 +1 @@
-0.53.0
+0.53.1

waku/common/protocol.go

@@ -91,6 +91,11 @@ type WakuHost interface {
 	// OnMessagesRequest handles when the peer receive a message request
 	// this only works if the peer is a mailserver
 	OnMessagesRequest(MessagesRequest, Peer) error
+	// OnDeprecatedMessagesRequest handles when the peer receive a message request
+	// using the *Envelope format. Currently the only production client (status-react)
+	// is exclusively using this one.
+	OnDeprecatedMessagesRequest(*Envelope, Peer) error
+
 	OnBatchAcknowledged(common.Hash, Peer) error
 	OnP2PRequestCompleted([]byte, Peer) error
 }

waku/v0/peer.go

@@ -301,6 +301,13 @@ func (p *Peer) handleP2PRequestCode(packet p2p.Msg) error {
 	r := bytes.NewReader(data)
 	packet.Payload = r
 
+	var requestDeprecated common.Envelope
+	errDepReq := packet.Decode(&requestDeprecated)
+	if errDepReq == nil {
+		return p.host.OnDeprecatedMessagesRequest(&requestDeprecated, p)
+	}
+	p.logger.Info("failed to decode p2p request message (deprecated)", zap.Binary("peer", p.ID()), zap.Error(errDepReq))
+
 	// As we failed to decode the request, let's set the offset
 	// to the beginning and try decode it again.
 	if _, err := r.Seek(0, io.SeekStart); err != nil {

waku/v1/peer.go

@@ -301,6 +301,13 @@ func (p *Peer) handleP2PRequestCode(packet p2p.Msg) error {
 	r := bytes.NewReader(data)
 	packet.Payload = r
 
+	var requestDeprecated common.Envelope
+	errDepReq := packet.Decode(&requestDeprecated)
+	if errDepReq == nil {
+		return p.host.OnDeprecatedMessagesRequest(&requestDeprecated, p)
+	}
+	p.logger.Info("failed to decode p2p request message (deprecated)", zap.Binary("peer", p.ID()), zap.Error(errDepReq))
+
 	// As we failed to decode the request, let's set the offset
 	// to the beginning and try decode it again.
 	if _, err := r.Seek(0, io.SeekStart); err != nil {

waku/waku.go

@@ -1103,6 +1103,11 @@ func (w *Waku) OnMessagesRequest(request common.MessagesRequest, p common.Peer)
 	return nil
 }
 
+func (w *Waku) OnDeprecatedMessagesRequest(request *common.Envelope, p common.Peer) error {
+	w.mailServer.DeliverMail(p.ID(), request)
+	return nil
+}
+
 func (w *Waku) OnP2PRequestCompleted(payload []byte, p common.Peer) error {
 	msEvent, err := CreateMailServerEvent(p.EnodeID(), payload)
 	if err != nil {

waku/waku_version_test.go

@@ -19,6 +19,7 @@
 package waku
 
 import (
+	"errors"
 	mrand "math/rand"
 	"testing"
 	"time"
@@ -35,6 +36,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/status-im/status-go/protocol/tt"
 )
 
 func TestWakuV0(t *testing.T) {
@@ -457,6 +459,65 @@ func (s *WakuTestSuite) TestRequestSentEventWithExpiry() {
 	verifyEvent(common.EventMailServerRequestExpired)
 }
 
+type MockMailserver struct {
+	deliverMail func([]byte, *common.Envelope)
+}
+
+func (*MockMailserver) Archive(e *common.Envelope) {
+}
+
+func (*MockMailserver) Deliver(peerID []byte, r common.MessagesRequest) {
+}
+
+func (m *MockMailserver) DeliverMail(peerID []byte, e *common.Envelope) {
+
+	if m.deliverMail != nil {
+		m.deliverMail(peerID, e)
+	}
+}
+
+func (s *WakuTestSuite) TestDeprecatedDeliverMail() {
+
+	w1 := New(nil, nil)
+	w2 := New(nil, nil)
+
+	var deliverMailCalled bool
+
+	w2.RegisterMailServer(&MockMailserver{
+		deliverMail: func(peerID []byte, e *common.Envelope) {
+			deliverMailCalled = true
+		},
+	})
+
+	rw1, rw2 := p2p.MsgPipe()
+	p1 := s.newPeer(w1, p2p.NewPeer(enode.ID{1}, "1", []p2p.Cap{{"waku", 0}}), rw2, nil)
+
+	go func() { handleError(s.T(), w1.HandlePeer(p1, rw2)) }()
+
+	timer := time.AfterFunc(5*time.Second, func() {
+		handleError(s.T(), rw1.Close())
+	})
+	peer2 := s.newPeer(w2, p2p.NewPeer(enode.ID{1}, "1", nil), rw1, nil)
+	s.Require().NoError(peer2.Start())
+
+	go func() { handleError(s.T(), peer2.Run()) }()
+
+	s.Require().NoError(w1.RequestHistoricMessages(p1.ID(), &common.Envelope{Data: []byte{1}}))
+
+	err := tt.RetryWithBackOff(func() error {
+		if !deliverMailCalled {
+			return errors.New("DeliverMail not called")
+		}
+		return nil
+	})
+	s.Require().NoError(err)
+	s.Require().NoError(rw1.Close())
+	s.Require().NoError(rw2.Close())
+
+	timer.Stop()
+
+}
+
 func (s *WakuTestSuite) TestSendMessagesRequest() {
 	validMessagesRequest := common.MessagesRequest{
 		ID:    make([]byte, 32),