fix_: persist left communities even for restored account (#5174)

This PR fixes #7858 by making sure left persisted communities are
restored during the backup restore flow

protocol/communities/manager.go

@@ -887,6 +887,10 @@ func (m *Manager) JoinedAndPendingCommunitiesWithRequests() ([]*Community, error
 	return m.persistence.JoinedAndPendingCommunitiesWithRequests(&m.identity.PublicKey)
 }
 
+func (m *Manager) LeftCommunities() ([]*Community, error) {
+	return m.persistence.LeftCommunities(&m.identity.PublicKey)
+}
+
 func (m *Manager) DeletedCommunities() ([]*Community, error) {
 	return m.persistence.DeletedCommunities(&m.identity.PublicKey)
 }

protocol/communities/persistence.go

@@ -327,6 +327,17 @@ func (p *Persistence) rowsToCommunities(rows *sql.Rows) (comms []*Community, err
 	return comms, nil
 }
 
+func (p *Persistence) LeftCommunities(memberIdentity *ecdsa.PublicKey) (comms []*Community, err error) {
+	query := communitiesBaseQuery + ` WHERE NOT c.Joined AND NOT c.spectated AND r.state != ?`
+
+	rows, err := p.db.Query(query, common.PubkeyToHex(memberIdentity), RequestToJoinStatePending)
+	if err != nil {
+		return nil, err
+	}
+
+	return p.rowsToCommunities(rows)
+}
+
 func (p *Persistence) JoinedAndPendingCommunitiesWithRequests(memberIdentity *ecdsa.PublicKey) (comms []*Community, err error) {
 	query := communitiesBaseQuery + ` WHERE c.Joined OR r.state = ?`
 

protocol/messenger_backup.go

@@ -26,6 +26,12 @@ var backupTickerInterval = 120 * time.Second
 // backups
 var backupIntervalSeconds uint64 = 28800
 
+type CommunitySet struct {
+	Joined  []*communities.Community
+	Left    []*communities.Community
+	Deleted []*communities.Community
+}
+
 func (m *Messenger) backupEnabled() (bool, error) {
 	return m.settings.BackupEnabled()
 }
@@ -286,20 +292,39 @@ func (m *Messenger) backupContacts(ctx context.Context) []*protobuf.Backup {
 	return backupMessages
 }
 
-func (m *Messenger) backupCommunities(ctx context.Context, clock uint64) ([]*protobuf.Backup, error) {
+func (m *Messenger) retrieveAllCommunities() (*CommunitySet, error) {
 	joinedCs, err := m.communitiesManager.JoinedAndPendingCommunitiesWithRequests()
 	if err != nil {
 		return nil, err
 	}
 
+	leftCs, err := m.communitiesManager.LeftCommunities()
+	if err != nil {
+		return nil, err
+	}
+
 	deletedCs, err := m.communitiesManager.DeletedCommunities()
 	if err != nil {
 		return nil, err
 	}
 
+	return &CommunitySet{
+		Joined:  joinedCs,
+		Left:    leftCs,
+		Deleted: deletedCs,
+	}, nil
+}
+
+func (m *Messenger) backupCommunities(ctx context.Context, clock uint64) ([]*protobuf.Backup, error) {
+	communitySet, err := m.retrieveAllCommunities()
+	if err != nil {
+		return nil, err
+	}
+
 	var backupMessages []*protobuf.Backup
-	cs := append(joinedCs, deletedCs...)
-	for _, c := range cs {
+	combinedCs := append(append(communitySet.Joined, communitySet.Left...), communitySet.Deleted...)
+
+	for _, c := range combinedCs {
 		_, beingImported := m.importingCommunities[c.IDString()]
 		if !beingImported {
 			backupMessage, err := m.backupCommunity(c, clock)

protocol/messenger_backup_test.go

@@ -917,3 +917,58 @@ func (s *MessengerBackupSuite) TestBackupChats() {
 	s.Require().True(ok)
 	s.Require().Equal("", chat.Name)
 }
+
+func (s *MessengerBackupSuite) TestLeftCommunitiesAreBackedUp() {
+	bob1 := s.m
+	// Create bob2
+	bob2, err := newMessengerWithKey(s.shh, bob1.identity, s.logger, nil)
+	s.Require().NoError(err)
+	defer TearDownMessenger(&s.Suite, bob2)
+
+	description := &requests.CreateCommunity{
+		Membership:  protobuf.CommunityPermissions_MANUAL_ACCEPT,
+		Name:        "other-status",
+		Color:       "#fffff4",
+		Description: "other status community description",
+	}
+
+	// Create another community chat
+	response, err := bob1.CreateCommunity(description, true)
+	s.Require().NoError(err)
+	s.Require().NotNil(response)
+	s.Require().Len(response.Communities(), 1)
+
+	newCommunity := response.Communities()[0]
+
+	response, err = bob1.LeaveCommunity(newCommunity.ID())
+	s.Require().NoError(err)
+	s.Require().NotNil(response)
+
+	// trigger artificial Backup
+	_, err = bob1.BackupData(context.Background())
+	s.Require().NoError(err)
+
+	communities, err := bob1.Communities()
+	s.Require().NoError(err)
+	s.Require().Len(communities, 1)
+
+	// Safety check
+	communities, err = bob2.Communities()
+	s.Require().NoError(err)
+	s.Require().Len(communities, 0)
+
+	// Wait for the message to reach its destination
+	_, err = WaitOnMessengerResponse(
+		bob2,
+		func(r *MessengerResponse) bool {
+			return r.BackupHandled
+		},
+		"no messages",
+	)
+
+	s.Require().NoError(err)
+
+	communities, err = bob2.JoinedCommunities()
+	s.Require().NoError(err)
+	s.Require().Len(communities, 0)
+}