Fix WITH attached to a nested set operation (UNION/INTERSECT/EXCEPT).

Parse analysis neglected to cover the case of a WITH clause attached to an
intermediate-level set operation; it only handled WITH at the top level
or WITH attached to a leaf-level SELECT.  Per report from Adam Mackler.

In HEAD, I rearranged the order of SelectStmt's fields to put withClause
with the other fields that can appear on non-leaf SelectStmts.  In back
branches, leave it alone to avoid a possible ABI break for third-party
code.

Back-patch to 8.4 where WITH support was added.

1 files changed, 16 insertions, 13 deletions

diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index bfd3ab941a7..263edb5a7a6 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -1322,6 +1322,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 	Node	   *limitOffset;
 	Node	   *limitCount;
 	List	   *lockingClause;
+	WithClause *withClause;
 	Node	   *node;
 	ListCell   *left_tlist,
 			   *lct,
@@ -1338,14 +1339,6 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 
 	qry->commandType = CMD_SELECT;
 
-	/* process the WITH clause independently of all else */
-	if (stmt->withClause)
-	{
-		qry->hasRecursive = stmt->withClause->recursive;
-		qry->cteList = transformWithClause(pstate, stmt->withClause);
-		qry->hasModifyingCTE = pstate->p_hasModifyingCTE;
-	}
-
 	/*
 	 * Find leftmost leaf SelectStmt.  We currently only need to do this in
 	 * order to deliver a suitable error message if there's an INTO clause
@@ -1375,11 +1368,13 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 	limitOffset = stmt->limitOffset;
 	limitCount = stmt->limitCount;
 	lockingClause = stmt->lockingClause;
+	withClause = stmt->withClause;
 
 	stmt->sortClause = NIL;
 	stmt->limitOffset = NULL;
 	stmt->limitCount = NULL;
 	stmt->lockingClause = NIL;
+	stmt->withClause = NULL;
 
 	/* We don't support FOR UPDATE/SHARE with set ops at the moment. */
 	if (lockingClause)
@@ -1387,6 +1382,14 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("SELECT FOR UPDATE/SHARE is not allowed with UNION/INTERSECT/EXCEPT")));
 
+	/* Process the WITH clause independently of all else */
+	if (withClause)
+	{
+		qry->hasRecursive = withClause->recursive;
+		qry->cteList = transformWithClause(pstate, withClause);
+		qry->hasModifyingCTE = pstate->p_hasModifyingCTE;
+	}
+
 	/*
 	 * Recursively transform the components of the tree.
 	 */
@@ -1572,10 +1575,10 @@ transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
 				 errmsg("SELECT FOR UPDATE/SHARE is not allowed with UNION/INTERSECT/EXCEPT")));
 
 	/*
-	 * If an internal node of a set-op tree has ORDER BY, LIMIT, or FOR UPDATE
-	 * clauses attached, we need to treat it like a leaf node to generate an
-	 * independent sub-Query tree.	Otherwise, it can be represented by a
-	 * SetOperationStmt node underneath the parent Query.
+	 * If an internal node of a set-op tree has ORDER BY, LIMIT, FOR UPDATE,
+	 * or WITH clauses attached, we need to treat it like a leaf node to
+	 * generate an independent sub-Query tree.  Otherwise, it can be
+	 * represented by a SetOperationStmt node underneath the parent Query.
 	 */
 	if (stmt->op == SETOP_NONE)
 	{
@@ -1586,7 +1589,7 @@ transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
 	{
 		Assert(stmt->larg != NULL && stmt->rarg != NULL);
 		if (stmt->sortClause || stmt->limitOffset || stmt->limitCount ||
-			stmt->lockingClause)
+			stmt->lockingClause || stmt->withClause)
 			isLeaf = true;
 		else
 			isLeaf = false;