Ensure that references to an outer subquery in the top scope of a subquery are correctly handled.

Author: nicktobey

enginetest/queries/queries.go

@@ -8178,6 +8178,12 @@ ORDER BY 1;`,
 			{3},
 		},
 	},
+	{
+		Query: "SELECT * FROM xy JOIN LATERAL (SELECT * FROM uv WHERE xy.x+1 = uv.u) uv2",
+		Expected: []sql.Row{
+			{0, 2, 1, 1}, {1, 0, 2, 2}, {2, 1, 3, 2},
+		},
+	},
 	{
 		Query: `
 select * from mytable,

sql/planbuilder/scope.go

@@ -147,8 +147,8 @@ func (s *scope) resolveColumn(db, table, col string, checkParent, chooseFirst bo
 		return scopeColumn{}, false
 	}
 
-	if s.parent.activeSubquery != nil {
-		s.parent.activeSubquery.addOutOfScope(c.id)
+	if s.activeSubquery != nil {
+		s.activeSubquery.addOutOfScope(c.id)
 	}
 	return c, true
 }