Fix issue with DMs shown as normal rooms (#2776)

Fixes #2121, test added in
https://github.com/matrix-org/complement/pull/494

roomserver/internal/helpers/helpers.go

@@ -7,6 +7,9 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/roomserver/auth"
 	"github.com/matrix-org/dendrite/roomserver/state"
@@ -14,8 +17,6 @@ import (
 	"github.com/matrix-org/dendrite/roomserver/storage/shared"
 	"github.com/matrix-org/dendrite/roomserver/storage/tables"
 	"github.com/matrix-org/dendrite/roomserver/types"
-	"github.com/matrix-org/gomatrixserverlib"
-	"github.com/matrix-org/util"
 )
 
 // TODO: temporary package which has helper functions used by both internal/perform packages.
@@ -97,35 +98,35 @@ func IsServerCurrentlyInRoom(ctx context.Context, db storage.Database, serverNam
 func IsInvitePending(
 	ctx context.Context, db storage.Database,
 	roomID, userID string,
-) (bool, string, string, error) {
+) (bool, string, string, *gomatrixserverlib.Event, error) {
 	// Look up the room NID for the supplied room ID.
 	info, err := db.RoomInfo(ctx, roomID)
 	if err != nil {
-		return false, "", "", fmt.Errorf("r.DB.RoomInfo: %w", err)
+		return false, "", "", nil, fmt.Errorf("r.DB.RoomInfo: %w", err)
 	}
 	if info == nil {
-		return false, "", "", fmt.Errorf("cannot get RoomInfo: unknown room ID %s", roomID)
+		return false, "", "", nil, fmt.Errorf("cannot get RoomInfo: unknown room ID %s", roomID)
 	}
 
 	// Look up the state key NID for the supplied user ID.
 	targetUserNIDs, err := db.EventStateKeyNIDs(ctx, []string{userID})
 	if err != nil {
-		return false, "", "", fmt.Errorf("r.DB.EventStateKeyNIDs: %w", err)
+		return false, "", "", nil, fmt.Errorf("r.DB.EventStateKeyNIDs: %w", err)
 	}
 	targetUserNID, targetUserFound := targetUserNIDs[userID]
 	if !targetUserFound {
-		return false, "", "", fmt.Errorf("missing NID for user %q (%+v)", userID, targetUserNIDs)
+		return false, "", "", nil, fmt.Errorf("missing NID for user %q (%+v)", userID, targetUserNIDs)
 	}
 
 	// Let's see if we have an event active for the user in the room. If
 	// we do then it will contain a server name that we can direct the
 	// send_leave to.
-	senderUserNIDs, eventIDs, err := db.GetInvitesForUser(ctx, info.RoomNID, targetUserNID)
+	senderUserNIDs, eventIDs, eventJSON, err := db.GetInvitesForUser(ctx, info.RoomNID, targetUserNID)
 	if err != nil {
-		return false, "", "", fmt.Errorf("r.DB.GetInvitesForUser: %w", err)
+		return false, "", "", nil, fmt.Errorf("r.DB.GetInvitesForUser: %w", err)
 	}
 	if len(senderUserNIDs) == 0 {
-		return false, "", "", nil
+		return false, "", "", nil, nil
 	}
 	userNIDToEventID := make(map[types.EventStateKeyNID]string)
 	for i, nid := range senderUserNIDs {
@@ -135,18 +136,20 @@ func IsInvitePending(
 	// Look up the user ID from the NID.
 	senderUsers, err := db.EventStateKeys(ctx, senderUserNIDs)
 	if err != nil {
-		return false, "", "", fmt.Errorf("r.DB.EventStateKeys: %w", err)
+		return false, "", "", nil, fmt.Errorf("r.DB.EventStateKeys: %w", err)
 	}
 	if len(senderUsers) == 0 {
-		return false, "", "", fmt.Errorf("no senderUsers")
+		return false, "", "", nil, fmt.Errorf("no senderUsers")
 	}
 
 	senderUser, senderUserFound := senderUsers[senderUserNIDs[0]]
 	if !senderUserFound {
-		return false, "", "", fmt.Errorf("missing user for NID %d (%+v)", senderUserNIDs[0], senderUsers)
+		return false, "", "", nil, fmt.Errorf("missing user for NID %d (%+v)", senderUserNIDs[0], senderUsers)
 	}
 
-	return true, senderUser, userNIDToEventID[senderUserNIDs[0]], nil
+	event, err := gomatrixserverlib.NewEventFromTrustedJSON(eventJSON, false, info.RoomVersion)
+
+	return true, senderUser, userNIDToEventID[senderUserNIDs[0]], event, err
 }
 
 // GetMembershipsAtState filters the state events to

roomserver/internal/perform/perform_join.go

@@ -22,6 +22,10 @@ import (
 	"time"
 
 	"github.com/getsentry/sentry-go"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
+	"github.com/tidwall/gjson"
+
 	fsAPI "github.com/matrix-org/dendrite/federationapi/api"
 	"github.com/matrix-org/dendrite/internal/eventutil"
 	"github.com/matrix-org/dendrite/roomserver/api"
@@ -32,8 +36,6 @@ import (
 	"github.com/matrix-org/dendrite/roomserver/storage"
 	"github.com/matrix-org/dendrite/roomserver/types"
 	"github.com/matrix-org/dendrite/setup/config"
-	"github.com/matrix-org/gomatrixserverlib"
-	"github.com/sirupsen/logrus"
 )
 
 type Joiner struct {
@@ -236,7 +238,7 @@ func (r *Joiner) performJoinRoomByID(
 
 	// Force a federated join if we're dealing with a pending invite
 	// and we aren't in the room.
-	isInvitePending, inviteSender, _, err := helpers.IsInvitePending(ctx, r.DB, req.RoomIDOrAlias, req.UserID)
+	isInvitePending, inviteSender, _, inviteEvent, err := helpers.IsInvitePending(ctx, r.DB, req.RoomIDOrAlias, req.UserID)
 	if err == nil && !serverInRoom && isInvitePending {
 		_, inviterDomain, ierr := gomatrixserverlib.SplitID('@', inviteSender)
 		if ierr != nil {
@@ -248,6 +250,17 @@ func (r *Joiner) performJoinRoomByID(
 		if inviterDomain != r.Cfg.Matrix.ServerName {
 			req.ServerNames = append(req.ServerNames, inviterDomain)
 			forceFederatedJoin = true
+			memberEvent := gjson.Parse(string(inviteEvent.JSON()))
+			// only set unsigned if we've got a content.membership, which we _should_
+			if memberEvent.Get("content.membership").Exists() {
+				req.Unsigned = map[string]interface{}{
+					"prev_sender": memberEvent.Get("sender").Str,
+					"prev_content": map[string]interface{}{
+						"is_direct":  memberEvent.Get("content.is_direct").Bool(),
+						"membership": memberEvent.Get("content.membership").Str,
+					},
+				}
+			}
 		}
 	}
 
@@ -348,6 +361,7 @@ func (r *Joiner) performFederatedJoinRoomByID(
 		UserID:      req.UserID,        // the user ID joining the room
 		ServerNames: req.ServerNames,   // the server to try joining with
 		Content:     req.Content,       // the membership event content
+		Unsigned:    req.Unsigned,      // the unsigned event content, if any
 	}
 	fedRes := fsAPI.PerformJoinResponse{}
 	r.FSAPI.PerformJoin(ctx, &fedReq, &fedRes)

roomserver/internal/perform/perform_leave.go

@@ -79,7 +79,7 @@ func (r *Leaver) performLeaveRoomByID(
 ) ([]api.OutputEvent, error) {
 	// If there's an invite outstanding for the room then respond to
 	// that.
-	isInvitePending, senderUser, eventID, err := helpers.IsInvitePending(ctx, r.DB, req.RoomID, req.UserID)
+	isInvitePending, senderUser, eventID, _, err := helpers.IsInvitePending(ctx, r.DB, req.RoomID, req.UserID)
 	if err == nil && isInvitePending {
 		_, senderDomain, serr := gomatrixserverlib.SplitID('@', senderUser)
 		if serr != nil {

roomserver/internal/query/query.go

@@ -872,7 +872,7 @@ func (r *Queryer) QueryRestrictedJoinAllowed(ctx context.Context, req *api.Query
 	// but we don't specify an authorised via user, since the event auth
 	// will allow the join anyway.
 	var pending bool
-	if pending, _, _, err = helpers.IsInvitePending(ctx, r.DB, req.RoomID, req.UserID); err != nil {
+	if pending, _, _, _, err = helpers.IsInvitePending(ctx, r.DB, req.RoomID, req.UserID); err != nil {
 		return fmt.Errorf("helpers.IsInvitePending: %w", err)
 	} else if pending {
 		res.Allowed = true