MinerGetBaseInfo: if miner is not found in lookback, check current

If miner is found in current state, just return nil base info as miner
cannot mine if he is not found in the lookback.

Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>

chain/stmgr/utils.go

@@ -461,12 +461,21 @@ func MinerGetBaseInfo(ctx context.Context, sm *StateManager, bcs beacon.Schedule
 		return nil, xerrors.Errorf("getting lookback miner actor state: %w", err)
 	}
 
+	// TODO: load the state instead of computing it?
 	lbst, _, err := sm.TipSetState(ctx, lbts)
 	if err != nil {
 		return nil, err
 	}
 
 	act, err := sm.LoadActorRaw(ctx, maddr, lbst)
+	if xerrors.Is(err, types.ErrActorNotFound) {
+		_, err := sm.LoadActor(ctx, maddr, ts)
+		if err != nil {
+			return nil, xerrors.Errorf("loading miner in current state: %w", err)
+		}
+
+		return nil, nil
+	}
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load miner actor: %w", err)
 	}