1 files changed, 33 insertions, 13 deletions

diff --git a/src/backend/optimizer/util/var.c b/src/backend/optimizer/util/var.c
index a544041122b..af58b2556d6 100644
--- a/src/backend/optimizer/util/var.c
+++ b/src/backend/optimizer/util/var.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.23 1999/08/22 20:14:54 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.24 1999/08/26 05:09:06 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,16 +19,23 @@
 #include "optimizer/var.h"
 
 
+typedef struct {
+	List	   *varlist;
+	bool		includeUpperVars;
+} pull_var_clause_context;
+
 static bool pull_varnos_walker(Node *node, List **listptr);
 static bool contain_var_clause_walker(Node *node, void *context);
-static bool pull_var_clause_walker(Node *node, List **listptr);
+static bool pull_var_clause_walker(Node *node,
+								   pull_var_clause_context *context);
 
 
 /*
  *		pull_varnos
  *
  *		Create a list of all the distinct varnos present in a parsetree
- *		(tlist or qual).
+ *		(tlist or qual).  Note that only varnos attached to level-zero
+ *		Vars are considered --- upper Vars refer to some other rtable!
  */
 List *
 pull_varnos(Node *node)
@@ -47,7 +54,7 @@ pull_varnos_walker(Node *node, List **listptr)
 	if (IsA(node, Var))
 	{
 		Var	   *var = (Var *) node;
-		if (!intMember(var->varno, *listptr))
+		if (var->varlevelsup == 0 && !intMember(var->varno, *listptr))
 			*listptr = lconsi(var->varno, *listptr);
 		return false;
 	}
@@ -56,7 +63,8 @@ pull_varnos_walker(Node *node, List **listptr)
 
 /*
  * contain_var_clause
- *	  Recursively scan a clause to discover whether it contains any Var nodes.
+ *	  Recursively scan a clause to discover whether it contains any Var nodes
+ *	  (of the current query level).
  *
  *	  Returns true if any varnode found.
  */
@@ -72,7 +80,11 @@ contain_var_clause_walker(Node *node, void *context)
 	if (node == NULL)
 		return false;
 	if (IsA(node, Var))
-		return true;			/* abort the tree traversal and return true */
+	{
+		if (((Var *) node)->varlevelsup == 0)
+			return true;		/* abort the tree traversal and return true */
+		return false;
+	}
 	return expression_tree_walker(node, contain_var_clause_walker, context);
 }
 
@@ -80,28 +92,36 @@ contain_var_clause_walker(Node *node, void *context)
  * pull_var_clause
  *	  Recursively pulls all var nodes from an expression clause.
  *
+ *	  Upper-level vars (with varlevelsup > 0) are included only
+ *	  if includeUpperVars is true.  Most callers probably want
+ *	  to ignore upper-level vars.
+ *
  *	  Returns list of varnodes found.  Note the varnodes themselves are not
  *	  copied, only referenced.
  */
 List *
-pull_var_clause(Node *clause)
+pull_var_clause(Node *clause, bool includeUpperVars)
 {
-	List	   *result = NIL;
+	pull_var_clause_context		context;
 
-	pull_var_clause_walker(clause, &result);
-	return result;
+	context.varlist = NIL;
+	context.includeUpperVars = includeUpperVars;
+
+	pull_var_clause_walker(clause, &context);
+	return context.varlist;
 }
 
 static bool
-pull_var_clause_walker(Node *node, List **listptr)
+pull_var_clause_walker(Node *node, pull_var_clause_context *context)
 {
 	if (node == NULL)
 		return false;
 	if (IsA(node, Var))
 	{
-		*listptr = lappend(*listptr, node);
+		if (((Var *) node)->varlevelsup == 0 || context->includeUpperVars)
+			context->varlist = lappend(context->varlist, node);
 		return false;
 	}
 	return expression_tree_walker(node, pull_var_clause_walker,
-								  (void *) listptr);
+								  (void *) context);
 }