feat!: Withdraw broadcast invites. Add Qr::WithdrawJoinBroadcast and Qr::ReviveJoinBroadcast QR code types. (#7439)

Add the ability to withdraw broadcast invite codes

After merging:
- [x] Create issues in iOS, Desktop and UT repositories

src/qr.rs

@@ -233,6 +233,31 @@ pub enum Qr {
         authcode: String,
     },
 
+    /// Ask the user if they want to withdraw their own broadcast channel invite QR code.
+    WithdrawJoinBroadcast {
+        /// The user-visible name of this broadcast channel
+        name: String,
+
+        /// A string of random characters,
+        /// uniquely identifying this broadcast channel across all databases/clients.
+        /// Called `grpid` for historic reasons:
+        /// The id of multi-user chats is always called `grpid` in the database
+        /// because groups were once the only multi-user chats.
+        grpid: String,
+
+        /// Contact ID. Always `ContactId::SELF`.
+        contact_id: ContactId,
+
+        /// Fingerprint of the contact's key as scanned from the QR code.
+        fingerprint: Fingerprint,
+
+        /// Invite number.
+        invitenumber: String,
+
+        /// Authentication code.
+        authcode: String,
+    },
+
     /// Ask the user if they want to revive their own QR code.
     ReviveVerifyContact {
         /// Contact ID.
@@ -269,6 +294,31 @@ pub enum Qr {
         authcode: String,
     },
 
+    /// Ask the user if they want to revive their own broadcast channel invite QR code.
+    ReviveJoinBroadcast {
+        /// The user-visible name of this broadcast channel
+        name: String,
+
+        /// A string of random characters,
+        /// uniquely identifying this broadcast channel across all databases/clients.
+        /// Called `grpid` for historic reasons:
+        /// The id of multi-user chats is always called `grpid` in the database
+        /// because groups were once the only multi-user chats.
+        grpid: String,
+
+        /// Contact ID. Always `ContactId::SELF`.
+        contact_id: ContactId,
+
+        /// Fingerprint of the contact's key as scanned from the QR code.
+        fingerprint: Fingerprint,
+
+        /// Invite number.
+        invitenumber: String,
+
+        /// Authentication code.
+        authcode: String,
+    },
+
     /// `dclogin:` scheme parameters.
     ///
     /// Ask the user if they want to login with the email address.
@@ -500,14 +550,40 @@ async fn decode_openpgp(context: &Context, qr: &str) -> Result<Qr> {
                 })
             }
         } else if let (Some(grpid), Some(name)) = (grpid, broadcast_name) {
-            Ok(Qr::AskJoinBroadcast {
-                name,
-                grpid,
-                contact_id,
-                fingerprint,
-                invitenumber,
-                authcode,
-            })
+            if context
+                .is_self_addr(&addr)
+                .await
+                .with_context(|| format!("Can't check if {addr:?} is our address"))?
+            {
+                if token::exists(context, token::Namespace::InviteNumber, &invitenumber).await? {
+                    Ok(Qr::WithdrawJoinBroadcast {
+                        name,
+                        grpid,
+                        contact_id,
+                        fingerprint,
+                        invitenumber,
+                        authcode,
+                    })
+                } else {
+                    Ok(Qr::ReviveJoinBroadcast {
+                        name,
+                        grpid,
+                        contact_id,
+                        fingerprint,
+                        invitenumber,
+                        authcode,
+                    })
+                }
+            } else {
+                Ok(Qr::AskJoinBroadcast {
+                    name,
+                    grpid,
+                    contact_id,
+                    fingerprint,
+                    invitenumber,
+                    authcode,
+                })
+            }
         } else if context.is_self_addr(&addr).await? {
             if token::exists(context, token::Namespace::InviteNumber, &invitenumber).await? {
                 Ok(Qr::WithdrawVerifyContact {
@@ -800,6 +876,12 @@ pub async fn set_config_from_qr(context: &Context, qr: &str) -> Result<()> {
             invitenumber,
             authcode,
             ..
+        }
+        | Qr::WithdrawJoinBroadcast {
+            grpid,
+            invitenumber,
+            authcode,
+            ..
         } => {
             token::delete(context, &grpid).await?;
             context
@@ -829,6 +911,12 @@ pub async fn set_config_from_qr(context: &Context, qr: &str) -> Result<()> {
             authcode,
             grpid,
             ..
+        }
+        | Qr::ReviveJoinBroadcast {
+            invitenumber,
+            authcode,
+            grpid,
+            ..
         } => {
             let timestamp = time();
             token::save(

src/qr/qr_tests.rs

@@ -1,5 +1,5 @@
 use super::*;
-use crate::chat::create_group;
+use crate::chat::{Chat, create_broadcast, create_group, get_chat_contacts};
 use crate::config::Config;
 use crate::login_param::EnteredCertificateChecks;
 use crate::provider::Socket;
@@ -511,6 +511,56 @@ async fn test_withdraw_verifygroup() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_withdraw_joinbroadcast() -> Result<()> {
+    let mut tcm = TestContextManager::new();
+    let alice = &tcm.alice().await;
+    let bob = &tcm.bob().await;
+    let chat_id = create_broadcast(alice, "foo".to_string()).await?;
+    let qr = get_securejoin_qr(alice, Some(chat_id)).await?;
+
+    // scanning own verify-group code offers withdrawing
+    if let Qr::WithdrawJoinBroadcast { name, .. } = check_qr(alice, &qr).await? {
+        assert_eq!(name, "foo");
+    } else {
+        bail!("Wrong QR type, expected WithdrawJoinBroadcast");
+    }
+    set_config_from_qr(alice, &qr).await?;
+
+    // scanning withdrawn verify-group code offers reviving
+    if let Qr::ReviveJoinBroadcast { name, .. } = check_qr(alice, &qr).await? {
+        assert_eq!(name, "foo");
+    } else {
+        bail!("Wrong QR type, expected ReviveJoinBroadcast");
+    }
+
+    // someone else always scans as ask-verify-group
+    if let Qr::AskJoinBroadcast { name, .. } = check_qr(bob, &qr).await? {
+        assert_eq!(name, "foo");
+    } else {
+        bail!("Wrong QR type, expected AskJoinBroadcast");
+    }
+    assert!(set_config_from_qr(bob, &qr).await.is_err());
+
+    // Bob can't join using this QR code, since it's still withdrawn
+    let bob_chat_id = tcm.exec_securejoin_qr(bob, alice, &qr).await;
+    let bob_chat = Chat::load_from_db(bob, bob_chat_id).await?;
+    assert_eq!(bob_chat.is_self_in_chat(bob).await?, false);
+    assert_eq!(get_chat_contacts(alice, chat_id).await?.len(), 0);
+
+    // Revive
+    set_config_from_qr(alice, &qr).await?;
+
+    // Now Bob can join
+    let bob_chat_id2 = tcm.exec_securejoin_qr(bob, alice, &qr).await;
+    assert_eq!(bob_chat_id, bob_chat_id2);
+    let bob_chat = Chat::load_from_db(bob, bob_chat_id).await?;
+    assert_eq!(bob_chat.is_self_in_chat(bob).await?, true);
+    assert_eq!(get_chat_contacts(alice, chat_id).await?.len(), 1);
+
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn test_withdraw_multidevice() -> Result<()> {
     let mut tcm = TestContextManager::new();