UDAF incorrect error on some joins

The following query should return a valid value. It creates an error:

MariaDB [ssb]> select
-> ssq(lo_linenumber)
-> from (select lo_linenumber, lo_custkey
-> from lineorder where lo_custkey in (29998,29999,30000)) a,
-> customer where c_custkey = lo_custkey;
ERROR 1815 (HY000): Internal error: An unexpected condition within the query caused an internal processing error within InfiniDB. Please check the log files for more details. Additional Information: error in TupleAggregateStep.
MariaDB [ssb]>

The problem appears to be that when processing a large dataset in this particular case, one rowgroup is left on a queue and is processed without the user data. I have checked and it appears all the PM processing is correct.