From 00340faa3be64541f6fac2bca55880f621f940d0 Mon Sep 17 00:00:00 2001
From: satyanarayana narlapuram <satyanarlapuram@gmail.com>
Date: Tue, 21 Apr 2026 14:33:33 +0000
Subject: [PATCH] Add Graph* node support to expression_tree_mutator

expression_tree_mutator_impl() was missing case handlers for
T_GraphPattern, T_GraphElementPattern, and T_GraphPropertyRef.
The corresponding expression_tree_walker_impl() already handled
all three node types, but the mutator did not, causing an
"unrecognized node type: 106" error whenever a GRAPH_TABLE
subquery appeared in a HAVING clause.

The fix adds three case handlers mirroring the walker:
- T_GraphPropertyRef: leaf node, FLATCOPY only
- T_GraphElementPattern: FLATCOPY + MUTATE subexpr, whereClause
- T_GraphPattern: FLATCOPY + MUTATE path_pattern_list, whereClause
---
 src/backend/nodes/nodeFuncs.c             | 31 +++++++++++++++++++++++
 src/test/regress/expected/graph_table.out | 15 +++++++++++
 src/test/regress/sql/graph_table.sql      |  9 +++++++
 3 files changed, 55 insertions(+)

diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index c0b880ec..c18f2b0e 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -3810,6 +3810,37 @@ expression_tree_mutator_impl(Node *node,
 				return (Node *) newnode;
 			}
 			break;
+		case T_GraphPropertyRef:
+			{
+				GraphPropertyRef *newnode;
+
+				FLATCOPY(newnode, node, GraphPropertyRef);
+				/* leaf node, no expression subnodes */
+				return (Node *) newnode;
+			}
+			break;
+		case T_GraphElementPattern:
+			{
+				GraphElementPattern *gep = (GraphElementPattern *) node;
+				GraphElementPattern *newnode;
+
+				FLATCOPY(newnode, gep, GraphElementPattern);
+				MUTATE(newnode->subexpr, gep->subexpr, List *);
+				MUTATE(newnode->whereClause, gep->whereClause, Node *);
+				return (Node *) newnode;
+			}
+			break;
+		case T_GraphPattern:
+			{
+				GraphPattern *gp = (GraphPattern *) node;
+				GraphPattern *newnode;
+
+				FLATCOPY(newnode, gp, GraphPattern);
+				MUTATE(newnode->path_pattern_list, gp->path_pattern_list, List *);
+				MUTATE(newnode->whereClause, gp->whereClause, Node *);
+				return (Node *) newnode;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
diff --git a/src/test/regress/expected/graph_table.out b/src/test/regress/expected/graph_table.out
index b579e3df..5e57d248 100644
--- a/src/test/regress/expected/graph_table.out
+++ b/src/test/regress/expected/graph_table.out
@@ -1022,4 +1022,19 @@ SELECT sname, dname FROM GRAPH_TABLE (g1 MATCH (src)->(dest) WHERE src.vprop1 >
 ERROR:  subqueries within GRAPH_TABLE reference are not supported
 SELECT sname, dname FROM GRAPH_TABLE (g1 MATCH (src)->(dest) WHERE out_degree(src.vname) > (SELECT max(out_degree(nname)) FROM GRAPH_TABLE (g1 MATCH (node) COLUMNS (node.vname AS nname))) COLUMNS(src.vname AS sname, dest.vname AS dname));
 ERROR:  subqueries within GRAPH_TABLE reference are not supported
+-- GRAPH_TABLE subquery in HAVING clause
+SELECT src.vname, count(*)
+  FROM v1 AS src
+  GROUP BY src.vname
+  HAVING count(*) >= (SELECT count(*)
+                        FROM GRAPH_TABLE (g1 MATCH (a IS vl1)
+                                          COLUMNS (a.vname AS n))
+                       WHERE n = src.vname);
+ vname | count 
+-------+-------
+ v13   |     1
+ v12   |     1
+ v11   |     1
+(3 rows)
+
 -- leave the objects behind for pg_upgrade/pg_dump tests
diff --git a/src/test/regress/sql/graph_table.sql b/src/test/regress/sql/graph_table.sql
index 4ff98817..3d5224d3 100644
--- a/src/test/regress/sql/graph_table.sql
+++ b/src/test/regress/sql/graph_table.sql
@@ -582,4 +582,13 @@ SELECT * FROM customers co WHERE co.customer_id = (SELECT customer_id FROM GRAPH
 SELECT sname, dname FROM GRAPH_TABLE (g1 MATCH (src)->(dest) WHERE src.vprop1 > (SELECT max(v1.vprop1) FROM v1) COLUMNS(src.vname AS sname, dest.vname AS dname));
 SELECT sname, dname FROM GRAPH_TABLE (g1 MATCH (src)->(dest) WHERE out_degree(src.vname) > (SELECT max(out_degree(nname)) FROM GRAPH_TABLE (g1 MATCH (node) COLUMNS (node.vname AS nname))) COLUMNS(src.vname AS sname, dest.vname AS dname));
 
+-- GRAPH_TABLE subquery in HAVING clause
+SELECT src.vname, count(*)
+  FROM v1 AS src
+  GROUP BY src.vname
+  HAVING count(*) >= (SELECT count(*)
+                        FROM GRAPH_TABLE (g1 MATCH (a IS vl1)
+                                          COLUMNS (a.vname AS n))
+                       WHERE n = src.vname);
+
 -- leave the objects behind for pg_upgrade/pg_dump tests
-- 
2.43.0