If a range-partitioned table has no default partition, reject null keys.

Commit 4e5fe9ad19 introduced this
problem.  Also add a test so it doesn't get broken again.

Report by Rushabh Lathia.  Fix by Amit Langote.  Reviewed by Rushabh
Lathia and Amul Sul.  Tweaked by me.

Discussion: http://postgr.es/m/CAGPqQf0Y1iJyk4QJBdMf=pS9i6Q0JUMM_h5-qkR3OMJ-e04PyA@mail.gmail.com

src/backend/catalog/partition.c

@@ -2553,11 +2553,10 @@ get_partition_for_tuple(Relation relation, Datum *values, bool *isnull)
 				 */
 				for (i = 0; i < key->partnatts; i++)
 				{
-					if (isnull[i] &&
-						partition_bound_has_default(partdesc->boundinfo))
+					if (isnull[i])
 					{
 						range_partkey_has_null = true;
-						part_index = partdesc->boundinfo->default_index;
+						break;
 					}
 				}
 

src/test/regress/expected/insert.out

@@ -659,6 +659,10 @@ create table mcrparted2 partition of mcrparted for values from (10, 6, minvalue)
 create table mcrparted3 partition of mcrparted for values from (11, 1, 1) to (20, 10, 10);
 create table mcrparted4 partition of mcrparted for values from (21, minvalue, minvalue) to (30, 20, maxvalue);
 create table mcrparted5 partition of mcrparted for values from (30, 21, 20) to (maxvalue, maxvalue, maxvalue);
+-- null not allowed in range partition
+insert into mcrparted values (null, null, null);
+ERROR:  no partition of relation "mcrparted" found for row
+DETAIL:  Partition key of the failing row contains (a, abs(b), c) = (null, null, null).
 -- routed to mcrparted0
 insert into mcrparted values (0, 1, 1);
 insert into mcrparted0 values (0, 1, 1);

src/test/regress/sql/insert.sql

@@ -421,6 +421,9 @@ create table mcrparted3 partition of mcrparted for values from (11, 1, 1) to (20
 create table mcrparted4 partition of mcrparted for values from (21, minvalue, minvalue) to (30, 20, maxvalue);
 create table mcrparted5 partition of mcrparted for values from (30, 21, 20) to (maxvalue, maxvalue, maxvalue);
 
+-- null not allowed in range partition
+insert into mcrparted values (null, null, null);
+
 -- routed to mcrparted0
 insert into mcrparted values (0, 1, 1);
 insert into mcrparted0 values (0, 1, 1);