From 94e981d7c773c21b52afdd1dbf6578f71e603781 Mon Sep 17 00:00:00 2001
From: xlanor <tanjingkai@me.com>
Date: Fri, 2 Oct 2020 01:44:23 +0800
Subject: [PATCH] Changed policiesList and rolesList from declaration to
 definition to fix nil error in encoding/json.
 https://github.com/golang/go/issues/27589#issuecomment-545976192

---
 engine/ladon/handler.go | 5 ++---
 storage/handler.go      | 8 ++++----
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/engine/ladon/handler.go b/engine/ladon/handler.go
index e3e7b3e02..32341d5c2 100644
--- a/engine/ladon/handler.go
+++ b/engine/ladon/handler.go
@@ -290,8 +290,7 @@ func (e *Engine) Register(r *httprouter.Router) {
 }
 
 func (e *Engine) rolesList(ctx context.Context, r *http.Request, ps httprouter.Params) (*kstorage.ListRequest, error) {
-	var p kstorage.Roles
-
+	p := make([]kstorage.Role, 0)
 	f, err := flavor(ps)
 	if err != nil {
 		return nil, err
@@ -428,8 +427,8 @@ func (e *Engine) policiesCreate(ctx context.Context, r *http.Request, ps httprou
 }
 
 func (e *Engine) policiesList(ctx context.Context, r *http.Request, ps httprouter.Params) (*kstorage.ListRequest, error) {
-	var p kstorage.Policies
 
+	p := make([]kstorage.Policy, 0)
 	f, err := flavor(ps)
 	if err != nil {
 		return nil, err
diff --git a/storage/handler.go b/storage/handler.go
index 9949e1dee..e4ed8efee 100644
--- a/storage/handler.go
+++ b/storage/handler.go
@@ -84,8 +84,8 @@ func (l *ListRequest) Filter(m map[string][]string) *ListRequest {
 
 func ListByQuery(l *ListRequest, m map[string][]string) {
 	switch val := l.Value.(type) {
-	case *Roles:
-		var res Roles
+	case *[]Role:
+		res := make([]Role, 0)
 		for _, role := range *val {
 			filteredRole := role.withMembers(m["member"]).withIDs(m["id"])
 			if filteredRole != nil {
@@ -93,8 +93,8 @@ func ListByQuery(l *ListRequest, m map[string][]string) {
 			}
 		}
 		l.Value = &res
-	case *Policies:
-		var res Policies
+	case *[]Policy:
+		res := make([]Policy, 0)
 		for _, policy := range *val {
 			filteredPolicy := policy.withSubjects(m["subject"]).withResources(m["resource"]).withActions(m["action"]).withIDs(m["id"])
 			if filteredPolicy != nil {