From 9eb94e5f488f795e74f46ceb3ec62fc355f2e1d4 Mon Sep 17 00:00:00 2001
From: "Alexander \"PapaTutuWawa" <papatutuwawa@polynom.me>
Date: Sat, 19 Oct 2024 21:45:18 +0200
Subject: [PATCH] fix(xep): Fix crash when the device list node is empty

---
 packages/moxxmpp/lib/src/xeps/xep_0384/errors.dart   | 4 ++++
 packages/moxxmpp/lib/src/xeps/xep_0384/xep_0384.dart | 5 ++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/packages/moxxmpp/lib/src/xeps/xep_0384/errors.dart b/packages/moxxmpp/lib/src/xeps/xep_0384/errors.dart
index 9a54334..7c5ae75 100644
--- a/packages/moxxmpp/lib/src/xeps/xep_0384/errors.dart
+++ b/packages/moxxmpp/lib/src/xeps/xep_0384/errors.dart
@@ -4,6 +4,10 @@ class UnknownOmemoError extends OmemoError {}
 
 class InvalidAffixElementsException implements Exception {}
 
+/// Internal exception that is returned when the device list cannot be
+/// fetched because the returned list is empty.
+class EmptyDeviceListException implements OmemoError {}
+
 class OmemoNotSupportedForContactException extends OmemoError {}
 
 class EncryptionFailedException implements Exception {}
diff --git a/packages/moxxmpp/lib/src/xeps/xep_0384/xep_0384.dart b/packages/moxxmpp/lib/src/xeps/xep_0384/xep_0384.dart
index 2edbb54..5d24875 100644
--- a/packages/moxxmpp/lib/src/xeps/xep_0384/xep_0384.dart
+++ b/packages/moxxmpp/lib/src/xeps/xep_0384/xep_0384.dart
@@ -535,7 +535,10 @@ class OmemoManager extends XmppManagerBase {
     final pm = getAttributes().getManagerById<PubSubManager>(pubsubManager)!;
     final result = await pm.getItems(jid.toBare(), omemoDevicesXmlns);
     if (result.isType<PubSubError>()) return Result(UnknownOmemoError());
-    return Result(result.get<List<PubSubItem>>().first.payload);
+
+    final itemList = result.get<List<PubSubItem>>();
+    if (itemList.isEmpty) return Result(EmptyDeviceListException());
+    return Result(itemList.first.payload);
   }
 
   /// Retrieves the OMEMO device list from [jid].