Partial fix for copied-plan bugs reported by Hiroshi Inoue:

_copyResult didn't copy subPlan structure completely.  _copyAgg is still
busted, apparently because of changes from EXCEPT/INTERSECT patch
(get_agg_tlist_references is no longer sufficient to find all aggregates).
No time to look at that tonight, however.

src/backend/nodes/copyfuncs.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.75 1999/03/01 00:10:30 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.76 1999/03/03 00:02:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,6 +30,7 @@
 #include "catalog/pg_type.h"
 #include "storage/lmgr.h"
 #include "optimizer/planmain.h"
+#include "optimizer/subselect.h"
 
 /*
  * listCopy
@@ -78,8 +79,6 @@ listCopy(List *list)
 static void
 CopyPlanFields(Plan *from, Plan *newnode)
 {
-	extern List *SS_pull_subplan(void *expr);
-
 	newnode->cost = from->cost;
 	newnode->plan_size = from->plan_size;
 	newnode->plan_width = from->plan_width;
@@ -93,7 +92,7 @@ CopyPlanFields(Plan *from, Plan *newnode)
 	newnode->chgParam = listCopy(from->chgParam);
 	Node_Copy(from, newnode, initPlan);
 	if (from->subPlan != NULL)
-		newnode->subPlan = SS_pull_subplan(newnode->qual);
+		newnode->subPlan = SS_pull_subplan((Node*) newnode->qual);
 	else
 		newnode->subPlan = NULL;
 	newnode->nParamExec = from->nParamExec;
@@ -139,6 +138,11 @@ _copyResult(Result *from)
 	 */
 	Node_Copy(from, newnode, resconstantqual);
 
+	/* We must add subplans in resconstantqual to the new plan's subPlan list
+	 */
+	newnode->plan.subPlan = nconc(newnode->plan.subPlan,
+								  SS_pull_subplan(newnode->resconstantqual));
+
 	return newnode;
 }
 

src/backend/optimizer/plan/subselect.c

@@ -426,6 +426,7 @@ SS_finalize_plan(Plan *plan)
 		case T_Result:
 			param_list = set_unioni(param_list,
 									_finalize_primnode(((Result *) plan)->resconstantqual, &subPlan));
+			/* subPlan is NOT necessarily NULL here ... */
 			break;
 
 		case T_Append:
@@ -503,10 +504,10 @@ SS_finalize_plan(Plan *plan)
 
 }
 
-List	   *SS_pull_subplan(void *expr);
+/* Construct a list of all subplans found within the given node tree */
 
 List *
-SS_pull_subplan(void *expr)
+SS_pull_subplan(Node *expr)
 {
 	List	   *result = NULL;
 
@@ -524,18 +525,18 @@ SS_pull_subplan(void *expr)
 		return SS_pull_subplan(((Iter *) expr)->iterexpr);
 	else if (or_clause(expr) || and_clause(expr) || is_opclause(expr) ||
 			 not_clause(expr) || is_funcclause(expr))
-		return SS_pull_subplan(((Expr *) expr)->args);
+		return SS_pull_subplan((Node *) ((Expr *) expr)->args);
 	else if (IsA(expr, Aggref))
 		return SS_pull_subplan(((Aggref *) expr)->target);
 	else if (IsA(expr, ArrayRef))
 	{
-		result = SS_pull_subplan(((ArrayRef *) expr)->refupperindexpr);
+		result = SS_pull_subplan((Node *)((ArrayRef *) expr)->refupperindexpr);
 		result = nconc(result,
-				  SS_pull_subplan(((ArrayRef *) expr)->reflowerindexpr));
+				SS_pull_subplan((Node*) ((ArrayRef *) expr)->reflowerindexpr));
 		result = nconc(result,
 					   SS_pull_subplan(((ArrayRef *) expr)->refexpr));
 		result = nconc(result,
-					 SS_pull_subplan(((ArrayRef *) expr)->refassgnexpr));
+					   SS_pull_subplan(((ArrayRef *) expr)->refassgnexpr));
 	}
 	else if (IsA(expr, TargetEntry))
 		return SS_pull_subplan(((TargetEntry *) expr)->expr);

src/include/optimizer/subselect.h

@@ -16,5 +16,6 @@ extern int	PlannerPlanId;		/* to assigne unique ID to subquery plans */
 extern List *SS_finalize_plan(Plan *plan);
 extern Node *SS_replace_correlation_vars(Node *expr);
 extern Node *SS_process_sublinks(Node *expr);
+extern List *SS_pull_subplan(Node *expr);
 
 #endif	 /* SUBSELECT_H */