Use a real RT index when setting up partition tuple routing.

Before, we always used a dummy value of 1, but that's not right when
the partitioned table being modified is inside of a WITH clause
rather than part of the main query.

Amit Langote, reported and reviewd by Etsuro Fujita, with a comment
change by me.

Discussion: http://postgr.es/m/ee12f648-8907-77b5-afc0-2980bcb0aa37@lab.ntt.co.jp

src/backend/commands/copy.c

@@ -1433,6 +1433,7 @@ BeginCopy(ParseState *pstate,
 						num_partitions;
 
 			ExecSetupPartitionTupleRouting(rel,
+										   1,
 										   &partition_dispatch_info,
 										   &partitions,
 										   &partition_tupconv_maps,

src/backend/executor/execMain.c

@@ -3213,6 +3213,7 @@ EvalPlanQualEnd(EPQState *epqstate)
  */
 void
 ExecSetupPartitionTupleRouting(Relation rel,
+							   Index resultRTindex,
 							   PartitionDispatch **pd,
 							   ResultRelInfo **partitions,
 							   TupleConversionMap ***tup_conv_maps,
@@ -3271,7 +3272,7 @@ ExecSetupPartitionTupleRouting(Relation rel,
 
 		InitResultRelInfo(leaf_part_rri,
 						  partrel,
-						  1,	/* dummy */
+						  resultRTindex,
 						  rel,
 						  0);
 

src/backend/executor/nodeModifyTable.c

@@ -1914,6 +1914,7 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
 					num_partitions;
 
 		ExecSetupPartitionTupleRouting(rel,
+									   node->nominalRelation,
 									   &partition_dispatch_info,
 									   &partitions,
 									   &partition_tupconv_maps,

src/include/executor/executor.h

@@ -207,6 +207,7 @@ extern void EvalPlanQualSetTuple(EPQState *epqstate, Index rti,
 					 HeapTuple tuple);
 extern HeapTuple EvalPlanQualGetTuple(EPQState *epqstate, Index rti);
 extern void ExecSetupPartitionTupleRouting(Relation rel,
+							   Index resultRTindex,
 							   PartitionDispatch **pd,
 							   ResultRelInfo **partitions,
 							   TupleConversionMap ***tup_conv_maps,

src/test/regress/expected/insert.out

@@ -506,5 +506,23 @@ DETAIL:  Failing row contains (2, hi there).
 insert into brtrigpartcon1 values (1, 'hi there');
 ERROR:  new row for relation "brtrigpartcon1" violates partition constraint
 DETAIL:  Failing row contains (2, hi there).
+-- check that the message shows the appropriate column description in a
+-- situation where the partitioned table is not the primary ModifyTable node
+create table inserttest3 (f1 text default 'foo', f2 text default 'bar', f3 int);
+create role regress_coldesc_role;
+grant insert on inserttest3 to regress_coldesc_role;
+grant insert on brtrigpartcon to regress_coldesc_role;
+revoke select on brtrigpartcon from regress_coldesc_role;
+set role regress_coldesc_role;
+with result as (insert into brtrigpartcon values (1, 'hi there') returning 1)
+  insert into inserttest3 (f3) select * from result;
+ERROR:  new row for relation "brtrigpartcon1" violates partition constraint
+DETAIL:  Failing row contains (a, b) = (2, hi there).
+reset role;
+-- cleanup
+revoke all on inserttest3 from regress_coldesc_role;
+revoke all on brtrigpartcon from regress_coldesc_role;
+drop role regress_coldesc_role;
+drop table inserttest3;
 drop table brtrigpartcon;
 drop function brtrigpartcon1trigf();

src/test/regress/sql/insert.sql

@@ -340,5 +340,23 @@ create or replace function brtrigpartcon1trigf() returns trigger as $$begin new.
 create trigger brtrigpartcon1trig before insert on brtrigpartcon1 for each row execute procedure brtrigpartcon1trigf();
 insert into brtrigpartcon values (1, 'hi there');
 insert into brtrigpartcon1 values (1, 'hi there');
+
+-- check that the message shows the appropriate column description in a
+-- situation where the partitioned table is not the primary ModifyTable node
+create table inserttest3 (f1 text default 'foo', f2 text default 'bar', f3 int);
+create role regress_coldesc_role;
+grant insert on inserttest3 to regress_coldesc_role;
+grant insert on brtrigpartcon to regress_coldesc_role;
+revoke select on brtrigpartcon from regress_coldesc_role;
+set role regress_coldesc_role;
+with result as (insert into brtrigpartcon values (1, 'hi there') returning 1)
+  insert into inserttest3 (f3) select * from result;
+reset role;
+
+-- cleanup
+revoke all on inserttest3 from regress_coldesc_role;
+revoke all on brtrigpartcon from regress_coldesc_role;
+drop role regress_coldesc_role;
+drop table inserttest3;
 drop table brtrigpartcon;
 drop function brtrigpartcon1trigf();