In case of tables created with round robin distribution the function get_plan_nodes_insert was trying to use an un-initialized local variable named constant.

Added a test case and changed the expected output too

3 files changed, 23 insertions, 4 deletions

diff --git a/src/backend/pgxc/plan/planner.c b/src/backend/pgxc/plan/planner.c
index 12a993cb72..2515e3fd77 100644
--- a/src/backend/pgxc/plan/planner.c
+++ b/src/backend/pgxc/plan/planner.c
@@ -531,7 +531,7 @@ get_plan_nodes_insert(PlannerInfo *root, RemoteQuery *step)
 	Query	   	*query = root->parse;
 	RangeTblEntry	*rte;
 	RelationLocInfo	*rel_loc_info;
-	Const	   	*constant;
+	Const	   	*constant = NULL;
 	ListCell	*lc;
 	Expr		*eval_expr = NULL;
 
@@ -707,8 +707,10 @@ get_plan_nodes_insert(PlannerInfo *root, RemoteQuery *step)
 		}
 	}
 
-	/* single call handles both replicated and partitioned types */
-	step->exec_nodes = GetRelationNodes(rel_loc_info, constant->constvalue, constant->consttype, RELATION_ACCESS_INSERT);
+	if (constant == NULL)
+		step->exec_nodes = GetRelationNodes(rel_loc_info, 0, InvalidOid, RELATION_ACCESS_INSERT);
+	else
+		step->exec_nodes = GetRelationNodes(rel_loc_info, constant->constvalue, constant->consttype, RELATION_ACCESS_INSERT);
 
 	if (eval_expr)
 		pfree(eval_expr);
diff --git a/src/test/regress/expected/xc_distkey.out b/src/test/regress/expected/xc_distkey.out
index e05fe7eb89..461f779e2b 100644
--- a/src/test/regress/expected/xc_distkey.out
+++ b/src/test/regress/expected/xc_distkey.out
@@ -103,8 +103,8 @@ insert into vc_tab values(NULL);
 select * from vc_tab order by a;
              a              
 ----------------------------
- A quick brown fox
  abcdefghijklmnopqrstuvwxyz
+ A quick brown fox
  
 (3 rows)
 
@@ -616,3 +616,13 @@ select * from tstz_tab_h where a = 'Jun 23, 2001 23:59:59.99 PST';
  Sun Jun 24 00:59:59.99 2001 PDT
 (1 row)
 
+create table my_rr_tab(a integer, b varchar(100)) distribute by round robin;
+insert into my_rr_tab values(1 , 'One');
+insert into my_rr_tab values(2, 'Two');
+select * from my_rr_tab order by a;
+ a |  b  
+---+-----
+ 1 | One
+ 2 | Two
+(2 rows)
+
diff --git a/src/test/regress/sql/xc_distkey.sql b/src/test/regress/sql/xc_distkey.sql
index 8650718d32..b57502d26f 100644
--- a/src/test/regress/sql/xc_distkey.sql
+++ b/src/test/regress/sql/xc_distkey.sql
@@ -243,3 +243,10 @@ select * from tstz_tab_h order by a;
 select * from tstz_tab_h where a = 'May 10, 2011 00:01:02.03 PST';
 select * from tstz_tab_h where a = 'Jun 23, 2001 23:59:59.99 PST';
 
+
+create table my_rr_tab(a integer, b varchar(100)) distribute by round robin;
+insert into my_rr_tab values(1 , 'One');
+insert into my_rr_tab values(2, 'Two');
+
+select * from my_rr_tab order by a;
+