More invite support (#979)

* Update gomatixserverlib

* Try to build invite stripped state if not given to us

* SendInvite improvements

* Transpose invite_room_state into invite_state.events for sync API

* Remove syncapi debugging output

* Use RespInviteV2

* Update gomatrixserverlib

* Send the invite event as a normal roomserver event too, for incorporating into room (should this be done by the roomserver automatically for invite inputs?)

* Federation sender use invite_room_state, room server try to insert membership state

* Check supported room versions on the invite endpoint

* Prevent roomserver query API from trying to handle requests for stub rooms

* Adding a nolint

* Replace IsRoomStub with RoomNIDExcludingStubs, fix query API to use that instead

* Review comments

3 files changed, 38 insertions, 0 deletions

diff --git a/roomserver/storage/interface.go b/roomserver/storage/interface.go
index 0235e51e..a13c44d6 100644
--- a/roomserver/storage/interface.go
+++ b/roomserver/storage/interface.go
@@ -71,6 +71,10 @@ type Database interface {
 	GetLatestEventsForUpdate(ctx context.Context, roomNID types.RoomNID) (types.RoomRecentEventsUpdater, error)
 	GetTransactionEventID(ctx context.Context, transactionID string, sessionID int64, userID string) (string, error)
 	RoomNID(ctx context.Context, roomID string) (types.RoomNID, error)
+	// RoomNIDExcludingStubs is a special variation of RoomNID that will return 0 as if the room
+	// does not exist if the room has no latest events. This can happen when we've received an
+	// invite over federation for a room that we don't know anything else about yet.
+	RoomNIDExcludingStubs(ctx context.Context, roomID string) (types.RoomNID, error)
 	LatestEventIDs(ctx context.Context, roomNID types.RoomNID) ([]gomatrixserverlib.EventReference, types.StateSnapshotNID, int64, error)
 	GetInvitesForUser(ctx context.Context, roomNID types.RoomNID, targetUserNID types.EventStateKeyNID) (senderUserIDs []types.EventStateKeyNID, err error)
 	SetRoomAlias(ctx context.Context, alias string, roomID string, creatorUserID string) error
diff --git a/roomserver/storage/postgres/storage.go b/roomserver/storage/postgres/storage.go
index 6f2b9661..5b5c61b0 100644
--- a/roomserver/storage/postgres/storage.go
+++ b/roomserver/storage/postgres/storage.go
@@ -471,6 +471,23 @@ func (d *Database) RoomNID(ctx context.Context, roomID string) (types.RoomNID, e
 	return roomNID, err
 }
 
+// RoomNIDExcludingStubs implements query.RoomserverQueryAPIDB
+func (d *Database) RoomNIDExcludingStubs(ctx context.Context, roomID string) (roomNID types.RoomNID, err error) {
+	roomNID, err = d.RoomNID(ctx, roomID)
+	if err != nil {
+		return
+	}
+	latestEvents, _, err := d.statements.selectLatestEventNIDs(ctx, roomNID)
+	if err != nil {
+		return
+	}
+	if len(latestEvents) == 0 {
+		roomNID = 0
+		return
+	}
+	return
+}
+
 // LatestEventIDs implements query.RoomserverQueryAPIDatabase
 func (d *Database) LatestEventIDs(
 	ctx context.Context, roomNID types.RoomNID,
diff --git a/roomserver/storage/sqlite3/storage.go b/roomserver/storage/sqlite3/storage.go
index 444a8fdd..5df9c4e0 100644
--- a/roomserver/storage/sqlite3/storage.go
+++ b/roomserver/storage/sqlite3/storage.go
@@ -590,6 +590,23 @@ func (d *Database) RoomNID(ctx context.Context, roomID string) (roomNID types.Ro
 	return
 }
 
+// RoomNIDExcludingStubs implements query.RoomserverQueryAPIDB
+func (d *Database) RoomNIDExcludingStubs(ctx context.Context, roomID string) (roomNID types.RoomNID, err error) {
+	roomNID, err = d.RoomNID(ctx, roomID)
+	if err != nil {
+		return
+	}
+	latestEvents, _, err := d.statements.selectLatestEventNIDs(ctx, nil, roomNID)
+	if err != nil {
+		return
+	}
+	if len(latestEvents) == 0 {
+		roomNID = 0
+		return
+	}
+	return
+}
+
 // LatestEventIDs implements query.RoomserverQueryAPIDatabase
 func (d *Database) LatestEventIDs(
 	ctx context.Context, roomNID types.RoomNID,