From 480500a95494df8323e81f2ddc702336bf7631fa Mon Sep 17 00:00:00 2001
From: Robert Virkus <robert.virkus@enough.de>
Date: Tue, 8 Jun 2021 11:31:34 +0200
Subject: [PATCH] fix login on servers without capabilities reponse

resolves #159
---
 lib/imap/imap_client.dart           |  5 +++++
 lib/src/imap/capability_parser.dart | 15 ++++++++-----
 test/imap/imap_client_test.dart     | 34 +++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/lib/imap/imap_client.dart b/lib/imap/imap_client.dart
index def1081c..793b24e7 100644
--- a/lib/imap/imap_client.dart
+++ b/lib/imap/imap_client.dart
@@ -217,6 +217,11 @@ class ImapClient extends ClientBase {
   void onConnectionEstablished(
       ConnectionInfo connectionInfo, String serverGreeting) {
     _serverInfo = ImapServerInfo(connectionInfo);
+    final startIndex = serverGreeting.indexOf('[CAPABILITY ');
+    if (startIndex != -1) {
+      CapabilityParser.parseCapabilities(
+          serverGreeting, startIndex + '[CAPABILITY '.length, _serverInfo);
+    }
     if (_queue.isNotEmpty) {
       // this can happen when a connection was re-established, e.g. when trying to complete an IDLE connection
       for (final task in _queue) {
diff --git a/lib/src/imap/capability_parser.dart b/lib/src/imap/capability_parser.dart
index 66d1cfed..d043b94b 100644
--- a/lib/src/imap/capability_parser.dart
+++ b/lib/src/imap/capability_parser.dart
@@ -6,6 +6,7 @@ import 'imap_response.dart';
 
 class CapabilityParser extends ResponseParser<List<Capability>> {
   final ImapServerInfo info;
+  List<Capability>? _capabilities;
   CapabilityParser(this.info);
 
   @override
@@ -13,9 +14,10 @@ class CapabilityParser extends ResponseParser<List<Capability>> {
       ImapResponse details, Response<List<Capability>> response) {
     if (response.isOkStatus) {
       if (details.parseText.startsWith('OK [CAPABILITY ')) {
-        parseCapabilities(details.first.line!, 'OK [CAPABILITY '.length);
+        parseCapabilities(details.first.line!, 'OK [CAPABILITY '.length, info);
+        _capabilities = info.capabilities;
       }
-      return info.capabilities;
+      return _capabilities ?? [];
     }
     return null;
   }
@@ -25,16 +27,19 @@ class CapabilityParser extends ResponseParser<List<Capability>> {
       ImapResponse details, Response<List<Capability>>? response) {
     var line = details.parseText;
     if (line.startsWith('OK [CAPABILITY ')) {
-      parseCapabilities(line, 'OK [CAPABILITY '.length);
+      parseCapabilities(line, 'OK [CAPABILITY '.length, info);
+      _capabilities = info.capabilities;
       return true;
     } else if (line.startsWith('CAPABILITY ')) {
-      parseCapabilities(line, 'CAPABILITY '.length);
+      parseCapabilities(line, 'CAPABILITY '.length, info);
+      _capabilities = info.capabilities;
       return true;
     }
     return super.parseUntagged(details, response);
   }
 
-  void parseCapabilities(String details, int startIndex) {
+  static void parseCapabilities(
+      String details, int startIndex, ImapServerInfo info) {
     var closeIndex = details.lastIndexOf(']');
     var capText;
     if (closeIndex == -1) {
diff --git a/test/imap/imap_client_test.dart b/test/imap/imap_client_test.dart
index 36e209c5..74027953 100644
--- a/test/imap/imap_client_test.dart
+++ b/test/imap/imap_client_test.dart
@@ -54,6 +54,40 @@ void main() {
     expect(capResponse[2].name, 'ENABLE');
   });
 
+  test('ImapClient login without capability', () async {
+    // setup own initial response for test:
+    client = ImapClient(bus: EventBus(sync: true), isLogEnabled: false);
+
+    client.eventBus
+        .on<ImapExpungeEvent>()
+        .listen((e) => expungedMessages.add(e.messageSequenceId));
+    client.eventBus
+        .on<ImapVanishedEvent>()
+        .listen((e) => vanishedMessages = e.vanishedMessages);
+    client.eventBus.on<ImapFetchEvent>().listen((e) => fetchEvents.add(e));
+
+    final connection = MockConnection();
+    client.connect(connection.socketClient,
+        connectionInformation: ConnectionInfo('imap.qq.com', 993, true));
+    mockServer = MockImapServer.connect(connection.socketServer);
+    connection.socketServer.write(
+        '* OK [CAPABILITY IMAP4 IMAP4rev1 ID AUTH=PLAIN AUTH=LOGIN AUTH=XOAUTH2 NAMESPACE] QQMail XMIMAP4Server ready\r\n');
+    // allow processing of server greeting:
+    await Future.delayed(const Duration(milliseconds: 15));
+
+    mockServer.response = '<tag> OK LOGIN completed';
+    final capResponse = await client.login('testuser', 'testpassword');
+    expect(capResponse, isNotNull,
+        reason: 'login response does not contain a result');
+    expect(capResponse.isEmpty, true,
+        reason: 'login response should not contain a single capability');
+    expect(capResponse.length, 0);
+    expect(client.serverInfo.capabilities, isNotNull);
+    expect(client.serverInfo.capabilities!.length, 7);
+    expect(client.serverInfo.capabilities![2].name, 'ID');
+    expect(client.serverInfo.capabilities![6].name, 'NAMESPACE');
+  });
+
   test('ImapClient authenticateWithOAuth2', () async {
     mockServer.response = '<tag> OK AUTH completed';
     final authResponse =