From 25dd858c18a4c9251c2948f8c18ac074854c13f5 Mon Sep 17 00:00:00 2001
From: Gani Georgiev <gani.georgiev@gmail.com>
Date: Fri, 17 Jan 2025 15:59:39 +0200
Subject: [PATCH] execute the delete realtime access checks against the
 non-transactional app instance

---
 apis/realtime.go | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/apis/realtime.go b/apis/realtime.go
index 4f2402a0..7d201ced 100644
--- a/apis/realtime.go
+++ b/apis/realtime.go
@@ -353,7 +353,10 @@ func bindRealtimeEvents(app core.App) {
 		Func: func(e *core.ModelEvent) error {
 			record := realtimeResolveRecord(e.App, e.Model, "")
 			if record != nil {
-				err := realtimeBroadcastRecord(e.App, "delete", record, true)
+				// note: use the outside scoped app instance for the access checks so that the API ruless
+				// are performed out of the delete transaction ensuring that they would still work even if
+				// a cascade-deleted record's API rule relies on an already deleted parent record
+				err := realtimeBroadcastRecord(e.App, "delete", record, true, app)
 				if err != nil {
 					app.Logger().Debug(
 						"Failed to dry cache record delete",
@@ -460,7 +463,11 @@ type recordData struct {
 	Action string `json:"action"`
 }
 
-func realtimeBroadcastRecord(app core.App, action string, record *core.Record, dryCache bool) error {
+// Note: the optAccessCheckApp is there in case you want the access check
+// to be performed against different db app context (e.g. out of a transaction).
+// If set, it is expected that optAccessCheckApp instance is used for read-only operations to avoid deadlocks.
+// If not set, it fallbacks to app.
+func realtimeBroadcastRecord(app core.App, action string, record *core.Record, dryCache bool, optAccessCheckApp ...core.App) error {
 	collection := record.Collection()
 	if collection == nil {
 		return errors.New("[broadcastRecord] Record collection not set")
@@ -486,6 +493,11 @@ func realtimeBroadcastRecord(app core.App, action string, record *core.Record, d
 
 	group := new(errgroup.Group)
 
+	accessCheckApp := app
+	if len(optAccessCheckApp) > 0 {
+		accessCheckApp = optAccessCheckApp[0]
+	}
+
 	for _, chunk := range chunks {
 		group.Go(func() error {
 			var clientAuth *core.Record
@@ -502,10 +514,6 @@ func realtimeBroadcastRecord(app core.App, action string, record *core.Record, d
 					clientAuth, _ = client.Get(RealtimeClientAuthKey).(*core.Record)
 
 					for sub, options := range subs {
-						// create a clean record copy without expand and unknown fields
-						// because we don't know yet which exact fields the client subscription has permissions to access
-						cleanRecord := record.Fresh()
-
 						// mock request data
 						requestInfo := &core.RequestInfo{
 							Context: core.RequestInfoContextRealtime,
@@ -515,10 +523,14 @@ func realtimeBroadcastRecord(app core.App, action string, record *core.Record, d
 							Auth:    clientAuth,
 						}
 
-						if !realtimeCanAccessRecord(app, cleanRecord, requestInfo, rule) {
+						if !realtimeCanAccessRecord(accessCheckApp, record, requestInfo, rule) {
 							continue
 						}
 
+						// create a clean record copy without expand and unknown fields because we don't know yet
+						// which exact fields the client subscription requested or has permissions to access
+						cleanRecord := record.Fresh()
+
 						// trigger the enrich hooks
 						enrichErr := triggerRecordEnrichHooks(app, requestInfo, []*core.Record{cleanRecord}, func() error {
 							// apply expand
@@ -541,7 +553,7 @@ func realtimeBroadcastRecord(app core.App, action string, record *core.Record, d
 							// for auth owner, superuser or manager
 							if collection.IsAuth() {
 								if isSameAuth(clientAuth, cleanRecord) ||
-									realtimeCanAccessRecord(app, cleanRecord, requestInfo, collection.ManageRule) {
+									realtimeCanAccessRecord(accessCheckApp, cleanRecord, requestInfo, collection.ManageRule) {
 									cleanRecord.IgnoreEmailVisibility(true)
 								}
 							}