BUG #15668: Server crash in transformPartitionRangeBounds

The following bug has been logged on the website:

Bug reference: 15668
Logged by: Alexander Lakhin
Email address: exclusion(at)gmail(dot)com
PostgreSQL version: Unsupported/Unknown
Operating system: Ubuntu 18.04
Description:

The following query:
CREATE TABLE range_parted (a int) PARTITION BY RANGE (a);
CREATE TABLE rp_part PARTITION OF range_parted FOR VALUES FROM
(unknown.unknown) TO (1);

crashes server (on the master branch) with the stack trace:
Core was generated by `postgres: law regression [local] CREATE TABLE
'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x0000560ab19ea0bc in transformPartitionRangeBounds
(pstate=pstate(at)entry=0x560ab3290da8, blist=<optimized out>,
parent=parent(at)entry=0x7f7846a6bea8) at parse_utilcmd.c:3754
3754 if (strcmp("minvalue", cname) == 0)
(gdb) bt
#0 0x0000560ab19ea0bc in transformPartitionRangeBounds
(pstate=pstate(at)entry=0x560ab3290da8, blist=<optimized out>,
parent=parent(at)entry=0x7f7846a6bea8) at parse_utilcmd.c:3754
#1 0x0000560ab19eea30 in transformPartitionBound
(pstate=pstate(at)entry=0x560ab3290da8,
parent=parent(at)entry=0x7f7846a6bea8, spec=0x560ab31fd448) at
parse_utilcmd.c:3706
#2 0x0000560ab1a4436f in DefineRelation (stmt=stmt(at)entry=0x560ab3295b30,
relkind=relkind(at)entry=114 'r', ownerId=10,
ownerId(at)entry=0, typaddress=typaddress(at)entry=0x0,
queryString=queryString(at)entry=0x560ab31da3b0 "CREATE TABLE rp_part
PARTITION OF range_parted FOR VALUES FROM (unknown.unknown) TO (1);") at
tablecmds.c:881
#3 0x0000560ab1bba086 in ProcessUtilitySlow
(pstate=pstate(at)entry=0x560ab3295a20, pstmt=pstmt(at)entry=0x560ab31db4b0,
queryString=queryString(at)entry=0x560ab31da3b0 "CREATE TABLE rp_part
PARTITION OF range_parted FOR VALUES FROM (unknown.unknown) TO (1);",
context=context(at)entry=PROCESS_UTILITY_TOPLEVEL, params=params(at)entry=0x0,
queryEnv=queryEnv(at)entry=0x0, completionTag=0x7ffcc3c17120 "",
dest=0x560ab31db590) at utility.c:1003
#4 0x0000560ab1bb8b60 in standard_ProcessUtility (pstmt=0x560ab31db4b0,
queryString=0x560ab31da3b0 "CREATE TABLE rp_part PARTITION OF
range_parted FOR VALUES FROM (unknown.unknown) TO (1);",
context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0,
dest=0x560ab31db590, completionTag=0x7ffcc3c17120 "")
at utility.c:923
#5 0x0000560ab1bb6022 in PortalRunUtility (portal=0x560ab32415e0,
pstmt=0x560ab31db4b0, isTopLevel=<optimized out>,
setHoldSnapshot=<optimized out>, dest=<optimized out>,
completionTag=0x7ffcc3c17120 "") at pquery.c:1175
#6 0x0000560ab1bb6ae0 in PortalRunMulti
(portal=portal(at)entry=0x560ab32415e0, isTopLevel=isTopLevel(at)entry=true,
setHoldSnapshot=setHoldSnapshot(at)entry=false,
dest=dest(at)entry=0x560ab31db590, altdest=altdest(at)entry=0x560ab31db590,
completionTag=completionTag(at)entry=0x7ffcc3c17120 "") at pquery.c:1328
#7 0x0000560ab1bb76da in PortalRun (portal=portal(at)entry=0x560ab32415e0,
count=count(at)entry=9223372036854775807,
isTopLevel=isTopLevel(at)entry=true, run_once=run_once(at)entry=true,
dest=dest(at)entry=0x560ab31db590,
altdest=altdest(at)entry=0x560ab31db590, completionTag=0x7ffcc3c17120 "")
at pquery.c:796
#8 0x0000560ab1bb3582 in exec_simple_query (
query_string=0x560ab31da3b0 "CREATE TABLE rp_part PARTITION OF
range_parted FOR VALUES FROM (unknown.unknown) TO (1);") at
postgres.c:1215
#9 0x0000560ab1bb54ee in PostgresMain (argc=<optimized out>,
argv=argv(at)entry=0x560ab32056a0, dbname=<optimized out>,
username=<optimized out>) at postgres.c:4256
#10 0x0000560ab1b42e00 in BackendRun (port=0x560ab31fdde0,
port=0x560ab31fdde0) at postmaster.c:4382
#11 BackendStartup (port=0x560ab31fdde0) at postmaster.c:4073
#12 ServerLoop () at postmaster.c:1703
#13 0x0000560ab1b43eb9 in PostmasterMain (argc=3, argv=0x560ab31d4a10) at
postmaster.c:1376
#14 0x0000560ab18e33a1 in main (argc=3, argv=0x560ab31d4a10) at main.c:228