Assertion failure when ATTACH partition followed by CREATE PARTITION.

Hi,

Assertion added in commits 6b2c4e59d016 is failing with following test:

CREATE TABLE sales
(
  prod_id           int,
  prod_quantity     int,
  sold_month        date
) PARTITION BY RANGE(sold_month);

CREATE TABLE public.sales_p1 PARTITION OF public.sales
FOR VALUES FROM (MINVALUE) TO ('2019-02-15');

CREATE TABLE sales_p2(like sales including all);
ALTER TABLE sales ATTACH PARTITION sales_p2
FOR VALUES FROM ('2019-02-15') TO ('2019-03-15');

CREATE TABLE fail PARTITION OF public.sales
FOR VALUES FROM ('2019-01-15') TO ('2019-02-15');


Here is the backtrace:

(gdb) bt
#0  0x00007fa373333277 in raise () from /lib64/libc.so.6
#1  0x00007fa373334968 in abort () from /lib64/libc.so.6
#2  0x0000000000abecdc in ExceptionalCondition (conditionName=0xc5de6d
"cmpval >= 0", errorType=0xc5cf03 "FailedAssertion", fileName=0xc5d03e
"partbounds.c", lineNumber=3092) at assert.c:69
#3  0x000000000086189c in check_new_partition_bound
(relname=0x7fff225f5ef0 "fail", parent=0x7fa3744868a0, spec=0x2e98888,
pstate=0x2e905e8) at partbounds.c:3092
#4  0x00000000006b44dc in DefineRelation (stmt=0x2e83198, relkind=114
'r', ownerId=10, typaddress=0x0, queryString=0x2dc07c0 "CREATE TABLE
fail PARTITION OF public.sales \nFOR VALUES FROM ('2019-01-15') TO
('2019-02-15');") at tablecmds.c:1011
#5  0x0000000000941430 in ProcessUtilitySlow (pstate=0x2e83080,
pstmt=0x2dc19b8, queryString=0x2dc07c0 "CREATE TABLE fail PARTITION OF
public.sales \nFOR VALUES FROM ('2019-01-15') TO ('2019-02-15');",
context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0,
dest=0x2dc1aa8, qc=0x7fff225f67c0) at utility.c:1163
#6  0x000000000094123e in standard_ProcessUtility (pstmt=0x2dc19b8,
queryString=0x2dc07c0 "CREATE TABLE fail PARTITION OF public.s ales
\nFOR VALUES FROM ('2019-01-15') TO ('2019-02-15');",
context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0,
dest=0x2dc1 aa8, qc=0x7fff225f67c0) at utility.c:1071
#7  0x0000000000940349 in ProcessUtility (pstmt=0x2dc19b8,
queryString=0x2dc07c0 "CREATE TABLE fail PARTITION OF public.sales
\nFO R VALUES FROM ('2019-01-15') TO ('2019-02-15');",
context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0,
dest=0x2dc1aa8, qc=0 x7fff225f67c0) at utility.c:524
#8  0x000000000093f163 in PortalRunUtility (portal=0x2e22ab0,
pstmt=0x2dc19b8, isTopLevel=true, setHoldSnapshot=false, dest=0x2dc1
aa8, qc=0x7fff225f67c0) at pquery.c:1159
#9  0x000000000093f380 in PortalRunMulti (portal=0x2e22ab0,
isTopLevel=true, setHoldSnapshot=false, dest=0x2dc1aa8, altdest=0x2dc1
aa8, qc=0x7fff225f67c0) at pquery.c:1305
#10 0x000000000093e882 in PortalRun (portal=0x2e22ab0,
count=9223372036854775807, isTopLevel=true, run_once=true,
dest=0x2dc1aa8, altdest=0x2dc1aa8, qc=0x7fff225f67c0) at pquery.c:779
#11 0x00000000009389e8 in exec_simple_query (query_string=0x2dc07c0
"CREATE TABLE fail PARTITION OF public.sales \nFOR VALUES FROM
('2019-01-15') TO ('2019-02-15');") at postgres.c:1239

Regards,
Amul Sul