Crash at cleanup_allocation_algorithm() when enable '--enable-cassert' option

when add option '--enable-cassert' in hawq configure, hawq will crash when run a test case of gpload. In the case, the default bucket num is 12 and the expected virtual segment number is 24 when external table exists.

reproduce steps :

1. hawq config -c default_hash_table_bucket_number -v 12 --skipvalidation
2. restart hawq
3. create table lineitem with the create.sql
4. update config_file, replace all $VAR with the correct value on your environment.
5. gpload -f config_file

THE LOG .
2016-11-15 06:43:45.635469 PST,,,p177585,th0,,,2016-11-15 06:43:38 PST,0,con5182,cmd6,seg-10000,,,,,"PANIC","XX000","Unexpected internal error: Master process received signal SIGSEGV",,,,,,,0,,,,"1 0x9ce6f2 postgres <symbol not found> (elog.c:4510)
2 0x9ce969 postgres StandardHandlerForSigillSigsegvSigbus_OnMainThread (elog.c:4597)
3 0x8e1c36 postgres CdbProgramErrorHandler (postgres.c:3513)
4 0x3e4380f7e0 libpthread.so.0 <symbol not found> (??:0)
5 0xb66a11 postgres calculate_planner_segment_num (cdbdatalocality.c:4431)
6 0x836555 postgres <symbol not found> (planner.c:667)
7 0x835d5e postgres planner (planner.c:475)
8 0x8dd67b postgres pg_plan_query (postgres.c:908)
9 0x8dd786 postgres pg_plan_queries (postgres.c:982)
10 0x8ded29 postgres <symbol not found> (postgres.c:1742)
"
2016-11-15 06:44:26.162520 PST,,,p78695,th-1193023200,,,,0,,,seg-10000,,,,,"LOG","00000","server process (PID 177585) was terminated by signal 11: Segmentation fault",,,,,,,0,,"postmaster.c",4748,
2016-11-15 06:44:26.162587 PST,,,p78695,th-1193023200,,,,0,,,seg-10000,,,,,"LOG","00000","terminating any other active server processes",,,,,,,0,,"postmaster.c",4486,

CORE DUMPED
(gdb) bt
#0 0x0000003e4380f6ab in raise () from /lib64/libpthread.so.0
#1 0x00000000009ce73f in SafeHandlerForSegvBusIll (processName=0xd27713 "Master process", postgres_signal_arg=11) at elog.c:4519
#2 0x00000000009ce969 in StandardHandlerForSigillSigsegvSigbus_OnMainThread (processName=0xd27713 "Master process", postgres_signal_arg=11) at elog.c:4597
#3 0x00000000008e1c36 in CdbProgramErrorHandler (postgres_signal_arg=11) at postgres.c:3512
#4 <signal handler called>
#5 0x0000000000b65a16 in cleanup_allocation_algorithm (context=0x7fffbd549cd0) at cdbdatalocality.c:3980
#6 0x0000000000b66a11 in calculate_planner_segment_num (query=0x307d5d0, resourceLife=QRL_ONCE, fullRangeTable=0x2ff2480, intoPolicy=0x0, sliceNum=2,
fixedVsegNum=-1) at cdbdatalocality.c:4430
#7 0x0000000000836555 in resource_negotiator (parse=0x307d708, cursorOptions=0, boundParams=0x0, resourceLife=QRL_ONCE, result=0x7fffbd54a018)
at planner.c:667
#8 0x0000000000835d5e in planner (parse=0x307d708, cursorOptions=0, boundParams=0x0, resourceLife=QRL_ONCE) at planner.c:473
#9 0x00000000008dd67b in pg_plan_query (querytree=0x307d708, boundParams=0x0, resource_life=QRL_ONCE) at postgres.c:908
#10 0x00000000008dd786 in pg_plan_queries (querytrees=0x2ed7960, boundParams=0x0, needSnapshot=0 '\000', resource_life=QRL_ONCE) at postgres.c:982
#11 0x00000000008ded29 in exec_simple_query (
query_string=0x2ed0898 "INSERT INTO public.\"lineitem\" (\"l_orderkey\",\"l_partkey\",\"l_suppkey\",\"l_linenumber\",\"l_quantity\",\"l_extendedprice\",\"l_discount\",\"l_tax\",\"l_returnflag\",\"l_linestatus\",\"l_shipdate\",\"l_commitdate\",\"l_rece"..., seqServerHost=0x0, seqServerPort=-1) at postgres.c:1742
#12 0x00000000008e3b44 in PostgresMain (argc=4, argv=0x2d38e60, username=0x2d38de0 "gpadmin") at postgres.c:4840
#13 0x000000000088d9eb in BackendRun (port=0x2d0a5f0) at postmaster.c:5915
#14 0x000000000088ce0a in BackendStartup (port=0x2d0a5f0) at postmaster.c:5484
#15 0x0000000000886e86 in ServerLoop () at postmaster.c:2163
#16 0x0000000000885e93 in PostmasterMain (argc=9, argv=0x2d13010) at postmaster.c:1454
#17 0x00000000007a3097 in main (argc=9, argv=0x2d13010) at main.c:226
(gdb)