From ccc57e56c3c6f2fb253ea5d8beb0ca995165b5c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jes=C3=BAs=20Espino?= <jespinog@gmail.com>
Date: Tue, 3 Mar 2020 17:52:59 +0100
Subject: [PATCH] MM-22235: Fixing stop/start behavior on Elasticsearch engine
 (#13887)

Co-authored-by: mattermod <mattermod@users.noreply.github.com>
---
 app/app_iface.go           |  2 +-
 app/license.go             | 15 ++++++++++-----
 app/server.go              | 10 +++++-----
 app/server_app_adapters.go |  2 +-
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/app/app_iface.go b/app/app_iface.go
index 41f6f902a4..466a697003 100644
--- a/app/app_iface.go
+++ b/app/app_iface.go
@@ -43,7 +43,7 @@ type AppIface interface {
 	AddConfigListener(listener func(*model.Config, *model.Config)) string
 	AddCursorIdsForPostList(originalList *model.PostList, afterPost, beforePost string, since int64, page, perPage int)
 	AddDirectChannels(teamId string, user *model.User) *model.AppError
-	AddLicenseListener(listener func()) string
+	AddLicenseListener(listener func(oldLicense, newLicense *model.License)) string
 	AddNotificationEmailToBatch(user *model.User, post *model.Post, team *model.Team) *model.AppError
 	AddPublicKey(name string, key io.Reader) *model.AppError
 	AddSamlIdpCertificate(fileData *multipart.FileHeader) *model.AppError
diff --git a/app/license.go b/app/license.go
index 2d0b1c38aa..023bba8f35 100644
--- a/app/license.go
+++ b/app/license.go
@@ -13,8 +13,6 @@ import (
 )
 
 func (a *App) LoadLicense() {
-	a.SetLicense(nil)
-
 	licenseId := ""
 	props, err := a.Srv().Store.System().Get()
 	if err == nil {
@@ -37,6 +35,7 @@ func (a *App) LoadLicense() {
 	record, err := a.Srv().Store.License().Get(licenseId)
 	if err != nil {
 		mlog.Info("License key from https://mattermost.com required to unlock enterprise features.")
+		a.SetLicense(nil)
 		return
 	}
 
@@ -108,9 +107,15 @@ func (a *App) License() *model.License {
 }
 
 func (a *App) SetLicense(license *model.License) bool {
+	oldLicense := a.Srv().licenseValue.Load()
+
 	defer func() {
 		for _, listener := range a.Srv().licenseListeners {
-			listener()
+			if oldLicense == nil {
+				listener(nil, license)
+			} else {
+				listener(oldLicense.(*model.License), license)
+			}
 		}
 	}()
 
@@ -169,13 +174,13 @@ func (a *App) RemoveLicense() *model.AppError {
 	return nil
 }
 
-func (s *Server) AddLicenseListener(listener func()) string {
+func (s *Server) AddLicenseListener(listener func(oldLicense, newLicense *model.License)) string {
 	id := model.NewId()
 	s.licenseListeners[id] = listener
 	return id
 }
 
-func (a *App) AddLicenseListener(listener func()) string {
+func (a *App) AddLicenseListener(listener func(oldLicense, newLicense *model.License)) string {
 	id := model.NewId()
 	a.Srv().licenseListeners[id] = listener
 	return id
diff --git a/app/server.go b/app/server.go
index 31c7d612e5..4f1acdc8a7 100644
--- a/app/server.go
+++ b/app/server.go
@@ -82,7 +82,7 @@ type Server struct {
 
 	licenseValue       atomic.Value
 	clientLicenseValue atomic.Value
-	licenseListeners   map[string]func()
+	licenseListeners   map[string]func(*model.License, *model.License)
 
 	timezones *timezones.Timezones
 
@@ -143,7 +143,7 @@ func NewServer(options ...Option) (*Server, error) {
 	s := &Server{
 		goroutineExitSignal: make(chan struct{}, 1),
 		RootRouter:          rootRouter,
-		licenseListeners:    map[string]func(){},
+		licenseListeners:    map[string]func(*model.License, *model.License){},
 		clientConfig:        make(map[string]string),
 	}
 
@@ -776,14 +776,14 @@ func (s *Server) StartElasticsearch() {
 		}
 	})
 
-	s.AddLicenseListener(func() {
-		if s.License() != nil {
+	s.AddLicenseListener(func(oldLicense, newLicense *model.License) {
+		if oldLicense == nil && newLicense != nil {
 			s.Go(func() {
 				if err := s.Elasticsearch.Start(); err != nil {
 					mlog.Error(err.Error())
 				}
 			})
-		} else {
+		} else if oldLicense != nil && newLicense == nil {
 			s.Go(func() {
 				if err := s.Elasticsearch.Stop(); err != nil {
 					mlog.Error(err.Error())
diff --git a/app/server_app_adapters.go b/app/server_app_adapters.go
index 470f56b6e2..2f13776cb6 100644
--- a/app/server_app_adapters.go
+++ b/app/server_app_adapters.go
@@ -39,7 +39,7 @@ func (s *Server) RunOldAppInitialization() error {
 			s.FakeApp().Publish(message)
 		})
 	})
-	s.FakeApp().Srv().licenseListenerId = s.FakeApp().AddLicenseListener(func() {
+	s.FakeApp().Srv().licenseListenerId = s.FakeApp().AddLicenseListener(func(oldLicense, newLicense *model.License) {
 		s.FakeApp().configOrLicenseListener()
 
 		message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_LICENSE_CHANGED, "", "", "", nil)