Recover room state for portals saved without it

Shared group portals were rejected unless their saved state said
private_group, so a group created through CreateGroup or a portal left
behind by a failed resync stopped sync permanently. Shared portals are
only ever created for groups, so return them as-is.

Portals with no saved state still fail on an incremental sync, which
omits the chat type. Move GetChatInfo's snapshot fallback into
resolveRoomState and use it for sync updates, chat deletion and
membership changes too.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: Fizzadar

pkg/connector/chatinfo.go

@@ -9,28 +9,12 @@ import (
 	"maunium.net/go/mautrix"
 	"maunium.net/go/mautrix/bridgev2"
 	"maunium.net/go/mautrix/bridgev2/networkid"
-	"maunium.net/go/mautrix/id"
 )
 
 // GetChatInfo uses saved native state, or fetches it when provisioning gets a
 // new room before the polling loop does. This read never advances the cursor.
 func (r *RedditClient) GetChatInfo(ctx context.Context, portal *bridgev2.Portal) (*bridgev2.ChatInfo, error) {
-	roomID := portalIDToRoomID(portal.ID)
-	state, key, err := r.roomState(ctx, roomID, &mautrix.SyncJoinedRoom{})
-	if errors.Is(err, errMissingChatType) {
-		full, fetchErr := r.fetchRoomSnapshots(ctx, []id.RoomID{roomID})
-		if fetchErr != nil {
-			return nil, fetchErr
-		}
-		joined := full.Rooms.Join[roomID]
-		if joined == nil {
-			joined, err = r.inviteSnapshot(full.Rooms.Invite[roomID])
-			if err != nil {
-				return nil, err
-			}
-		}
-		state, key, err = r.roomState(ctx, roomID, joined)
-	}
+	state, key, err := r.resolveRoomState(ctx, portalIDToRoomID(portal.ID), &mautrix.SyncJoinedRoom{})
 	if err != nil {
 		return nil, err
 	}

pkg/connector/chatsync.go

@@ -215,7 +215,7 @@ func (r *RedditClient) applyHiddenChatData(ctx context.Context, resp *redditchat
 }
 
 func (r *RedditClient) handleRoomUpdate(ctx context.Context, roomID id.RoomID, joined *mautrix.SyncJoinedRoom) error {
-	state, portalKey, err := r.roomState(ctx, roomID, joined)
+	state, portalKey, err := r.resolveRoomState(ctx, roomID, joined)
 	if err != nil {
 		return err
 	}

pkg/connector/membership.go

@@ -41,7 +41,7 @@ func (r *RedditClient) HandleMatrixMembership(ctx context.Context, msg *bridgev2
 		return nil, bridgev2.ErrMembershipNotSupported
 	}
 	roomID := portalIDToRoomID(msg.Portal.ID)
-	state, key, err := r.roomState(ctx, roomID, &mautrix.SyncJoinedRoom{})
+	state, key, err := r.resolveRoomState(ctx, roomID, &mautrix.SyncJoinedRoom{})
 	if err != nil {
 		return nil, err
 	}

pkg/connector/requests.go

@@ -58,7 +58,7 @@ func (r *RedditClient) HandleMatrixDeleteChat(ctx context.Context, msg *bridgev2
 		return errors.New("reddit chats cannot be deleted for everyone")
 	}
 	roomID := portalIDToRoomID(msg.Portal.ID)
-	state, key, err := r.roomState(ctx, roomID, &mautrix.SyncJoinedRoom{})
+	state, key, err := r.resolveRoomState(ctx, roomID, &mautrix.SyncJoinedRoom{})
 	if err != nil {
 		return err
 	}

pkg/connector/roomstate.go

@@ -165,15 +165,27 @@ func (r *RedditClient) savedRoomPortal(ctx context.Context, roomID id.RoomID) (*
 		return portal, err
 	}
 	key.Receiver = ""
-	portal, err = r.main.Bridge.DB.Portal.GetByKey(ctx, key)
-	if err != nil || portal == nil {
-		return portal, err
+	return r.main.Bridge.DB.Portal.GetByKey(ctx, key)
+}
+
+// A portal row can exist without saved state, e.g. after a failed resync, and
+// incremental syncs omit the chat type. Fetch the snapshot outside roomMu.
+func (r *RedditClient) resolveRoomState(ctx context.Context, roomID id.RoomID, joined *mautrix.SyncJoinedRoom) (*RoomState, networkid.PortalKey, error) {
+	state, key, err := r.roomState(ctx, roomID, joined)
+	if !errors.Is(err, errMissingChatType) {
+		return state, key, err
 	}
-	meta, ok := portal.Metadata.(*PortalMetadata)
-	if !ok || meta == nil || meta.State == nil || meta.State.Type != "private_group" {
-		return nil, errors.New("shared Reddit portal is not a known group")
+	full, err := r.fetchRoomSnapshots(ctx, []id.RoomID{roomID})
+	if err != nil {
+		return nil, networkid.PortalKey{}, err
+	}
+	snapshot := full.Rooms.Join[roomID]
+	if snapshot == nil {
+		if snapshot, err = r.inviteSnapshot(full.Rooms.Invite[roomID]); err != nil {
+			return nil, networkid.PortalKey{}, err
+		}
 	}
-	return portal, nil
+	return r.roomState(ctx, roomID, snapshot)
 }
 
 func (r *RedditClient) chatInfoFromState(state *RoomState) *bridgev2.ChatInfo {