Fix improper NULL handling in list partitioning code.

The previous logic was wrong when the value was NULL but there was
no partition for NULL.

Amit Langote, reviewed by Jeevan Ladhe

Discussion: http://postgr.es/m/d64f8498-70eb-3c88-b56d-c54fd3b0500f@lab.ntt.co.jp

3 files changed, 20 insertions, 3 deletions

diff --git a/src/backend/catalog/partition.c b/src/backend/catalog/partition.c
index b434c384c97..f9fd1366e26 100644
--- a/src/backend/catalog/partition.c
+++ b/src/backend/catalog/partition.c
@@ -1729,10 +1729,14 @@ get_partition_for_tuple(PartitionDispatch *pd,
 						errmsg("range partition key of row contains null")));
 		}
 
-		if (partdesc->boundinfo->has_null && isnull[0])
-			/* Tuple maps to the null-accepting list partition */
+		/*
+		 * A null partition key is only acceptable if null-accepting list
+		 * partition exists.
+		 */
+		cur_index = -1;
+		if (isnull[0] && partdesc->boundinfo->has_null)
 			cur_index = partdesc->boundinfo->null_index;
-		else
+		else if (!isnull[0])
 		{
 			/* Else bsearch in partdesc->boundinfo */
 			bool		equal = false;
diff --git a/src/test/regress/expected/insert.out b/src/test/regress/expected/insert.out
index 116854e1420..7fafa982126 100644
--- a/src/test/regress/expected/insert.out
+++ b/src/test/regress/expected/insert.out
@@ -365,6 +365,13 @@ DETAIL:  Failing row contains (1, 2).
 insert into mlparted1 (a, b) values (2, 3);
 ERROR:  new row for relation "mlparted11" violates partition constraint
 DETAIL:  Failing row contains (3, 2).
+-- check routing error through a list partitioned table when the key is null
+create table lparted_nonullpart (a int, b char) partition by list (b);
+create table lparted_nonullpart_a partition of lparted_nonullpart for values in ('a');
+insert into lparted_nonullpart values (1);
+ERROR:  no partition of relation "lparted_nonullpart" found for row
+DETAIL:  Partition key of the failing row contains (b) = (null).
+drop table lparted_nonullpart;
 -- check that RETURNING works correctly with tuple-routing
 alter table mlparted drop constraint check_b;
 create table mlparted12 partition of mlparted1 for values from (5) to (10);
diff --git a/src/test/regress/sql/insert.sql b/src/test/regress/sql/insert.sql
index c56c3c22f8e..f9c00705a22 100644
--- a/src/test/regress/sql/insert.sql
+++ b/src/test/regress/sql/insert.sql
@@ -226,6 +226,12 @@ insert into mlparted values (1, 2);
 -- selected by tuple-routing
 insert into mlparted1 (a, b) values (2, 3);
 
+-- check routing error through a list partitioned table when the key is null
+create table lparted_nonullpart (a int, b char) partition by list (b);
+create table lparted_nonullpart_a partition of lparted_nonullpart for values in ('a');
+insert into lparted_nonullpart values (1);
+drop table lparted_nonullpart;
+
 -- check that RETURNING works correctly with tuple-routing
 alter table mlparted drop constraint check_b;
 create table mlparted12 partition of mlparted1 for values from (5) to (10);