SegFault on 9.6.14

Greetings Hackers.

We have a reproduceable case of $subject that issues a backtrace such as
seen below.

The query that I'd prefer to sanitize before sending is <30 lines of at
a glance, not terribly complex logic.

It nonetheless dies hard after a few seconds of running and as expected,
results in an automatic all-backend restart.

Please advise on how to proceed. Thanks!

bt
#0 initscan (scan=scan(at)entry=0x55d7a7daa0b0, key=0x0, keep_startblock=keep_startblock(at)entry=1 '\001')
at /build/postgresql-9.6-5O8OLM/postgresql-9.6-9.6.14/build/../src/backend/access/heap/heapam.c:233
#1 0x000055d7a72fa8d0 in heap_rescan (scan=0x55d7a7daa0b0, key=key(at)entry=0x0) at /build/postgresql-9.6-5O8OLM/postgresql-9.6-9.6.14/build/../src/backend/access/heap/heapam.c:1529
#2 0x000055d7a7451fef in ExecReScanSeqScan (node=node(at)entry=0x55d7a7d85100) at /build/postgresql-9.6-5O8OLM/postgresql-9.6-9.6.14/build/../src/backend/executor/nodeSeqscan.c:280
#3 0x000055d7a742d36e in ExecReScan (node=0x55d7a7d85100) at /build/postgresql-9.6-5O8OLM/postgresql-9.6-9.6.14/build/../src/backend/executor/execAmi.c:158
#4 0x000055d7a7445d38 in ExecReScanGather (node=node(at)entry=0x55d7a7d84d30) at /build/postgresql-9.6-5O8OLM/postgresql-9.6-9.6.14/build/../src/backend/executor/nodeGather.c:475
#5 0x000055d7a742d255 in ExecReScan (node=0x55d7a7d84d30) at /build/postgresql-9.6-5O8OLM/postgresql-9.6-9.6.14/build/../src/backend/executor/execAmi.c:166
#6 0x000055d7a7448673 in ExecReScanHashJoin (node=node(at)entry=0x55d7a7d84110) at /build/postgresql-9.6-5O8OLM/postgresql-9.6-9.6.14/build/../src/backend/executor/nodeHashjoin.c:1019
#7 0x000055d7a742d29e in ExecReScan (node=node(at)entry=0x55d7a7d84110) at /build/postgresql-9.6-5O8OLM/postgresql-9.6-9.6.14/build/../src/backend/executor/execAmi.c:226
<about 30 lines omitted>

--
Jerry Sievers
Postgres DBA/Development Consulting
e: postgres(dot)consulting(at)comcast(dot)net