Incorrect ChatAdministratorRights behavior in Telegram iOS and Telegram for MacOS

[barsulka]

Checklist

• [ x ] I am reporting an issue in existing functionality that does not work as intended
• [ x ] I've searched for existing GitHub issues

Prerequisites

1. You need to have four different Telegram clients:

   • Telegram Desktop 5.9
   • Telegram for MacOS 11.5.269855 Stable
   • Telegram for Android 11.5.4 (5528)
   • Telegram iOS 11.5.1

2. You need a Telegram bot (either use an existing one or create a new one via BotFather).

3. You need a non-private group to which the Telegram bot has not been added yet.

Steps to Reproduce

1. Obtain the bot token {botId:botToken} from BotFather and the link https://t.me/{SomeBot}.

2. Call the setMyDefaultAdministratorRights method via the Bot API, setting all 15 rights to false:

   curl -X POST 'https://api.telegram.org/bot{botId:botToken}/setMyDefaultAdministratorRights' \
     -H 'Content-Type: application/json' \
     -d '{"rights":{"can_change_info":false,"can_delete_messages":false,"can_delete_stories":false,"can_edit_messages":false,"can_edit_stories":false,"can_invite_users":false,"can_manage_chat":false,"can_manage_topics":false,"can_manage_video_chats":false,"can_pin_messages":false,"can_post_messages":false,"can_post_stories":false,"can_promote_members":false,"can_restrict_members":false,"is_anonymous":false}}'

Expected response: {"ok":true,"result":true}

3. Verify the rights by calling getMyDefaultAdministratorRights:

   curl -X GET 'https://api.telegram.org/bot{botId:botToken}/getMyDefaultAdministratorRights'

   Expected response:

   {
     "ok": true,
     "result": {
       "can_manage_chat": false,
       "can_change_info": false,
       "can_delete_messages": false,
       "can_invite_users": false,
       "can_restrict_members": false,
       "can_pin_messages": false,
       "can_manage_topics": false,
       "can_promote_members": false,
       "can_manage_video_chats": false,
       "can_post_stories": false,
       "can_edit_stories": false,
       "can_delete_stories": false,
       "is_anonymous": false
     }
   }

   Note: You see 13 rights set to false. The can_post_messages and can_edit_messages rights apply only to channels, so their absence here is expected.

4. Open the link to add the bot to the group (as indicated in the official documentation): https://t.me/{SomeBot}?startgroup=1

5. In the window that appears, select the group to which the bot has not been added before.

Expected Behavior

One of two outcomes is expected:

• A confirmation prompt with "ok/cancel" appears before adding the bot, or
• A bot addition settings window opens where all admin rights toggles are off (especially the "Manage Group"
  toggle).

Actual Behavior

Client	Behavior	Screenshot
✅ Telegram for Android 11.5.4	An "Add Bot" window appears with toggles, where the "Manage Group" toggle is off, and at the bottom the button reads "Add bot as Member"
✅ Telegram Desktop 5.9	A confirmation dialog appears: "Add the bot to {groupname}?" with "cancel" and "ok" buttons
❌ Telegram for MacOS 11.5.269855	An "Add Bot" window opens where all rights are turned on, including "Admin Rights", and at the bottom the button reads "Add Bot as Admin"
❌ Telegram iOS 11.5.1	An "Add Bot" window opens where all rights are turned on, including "Admin Rights", and at the bottom the button reads "Add Bot as Admin"

Environment

Device: any

iOS version: any

App version: 11.5.1