Fix closed group session establishment issue

Signal/src/Loki/View Controllers/DeviceLinkingModal.swift

@@ -190,8 +190,11 @@ final class DeviceLinkingModal : Modal, DeviceLinkingSessionDelegate {
                     let thread = TSContactThread.getOrCreateThread(withContactId: slaveHexEncodedPublicKey, transaction: transaction)
                     thread.save(with: transaction)
                 }
-                let _ = SSKEnvironment.shared.syncManager.syncAllContacts()
-                let _ = SSKEnvironment.shared.syncManager.syncAllGroups()
+                let _ = SSKEnvironment.shared.syncManager.syncAllGroups().ensure {
+                    // Closed groups first because we prefer the session request mechanism
+                    // to the AFR mechanism
+                    let _ = SSKEnvironment.shared.syncManager.syncAllContacts()
+                }
                 let _ = SSKEnvironment.shared.syncManager.syncAllOpenGroups()
                 storage.dbReadWriteConnection.readWrite { transaction in
                     storage.setFriendRequestStatus(.friends, for: slaveHexEncodedPublicKey, transaction: transaction)

SignalMessaging/contacts/OWSSyncManager.m

@@ -270,8 +270,7 @@ NSString *const kSyncManagerLastContactSyncKey = @"kTSStorageManagerOWSSyncManag
 
 - (AnyPromise *)syncContact:(NSString *)hexEncodedPubKey transaction:(YapDatabaseReadTransaction *)transaction
 {
-    [LKSyncMessagesProtocol syncContactWithHexEncodedPublicKey:hexEncodedPubKey in:transaction];
-    return [AnyPromise promiseWithValue:@1];
+    return [LKSyncMessagesProtocol syncContactWithHexEncodedPublicKey:hexEncodedPubKey in:transaction];
 }
 
 - (AnyPromise *)syncAllContacts

SignalServiceKit/src/Contacts/SignalRecipient.h

@@ -42,6 +42,7 @@ NS_ASSUME_NONNULL_BEGIN
 + (void)markRecipientAsRegistered:(NSString *)recipientId
                          deviceId:(UInt32)deviceId
                       transaction:(YapDatabaseReadWriteTransaction *)transaction;
+
 + (void)markRecipientAsUnregistered:(NSString *)recipientId transaction:(YapDatabaseReadWriteTransaction *)transaction;
 
 @end

SignalServiceKit/src/Loki/Protocol/Session Management/SessionManagementProtocol.swift

@@ -180,6 +180,7 @@ public final class SessionManagementProtocol : NSObject {
         storage.setPreKeyBundle(preKeyBundle, forContact: hexEncodedPublicKey, transaction: transaction)
         // If we received a friend request (i.e. also a new pre key bundle), but we were already friends with the other user, reset the session.
         // The envelope type is set during UD decryption.
+        // TODO: Should this ignore session requests?
         if envelope.type == .friendRequest,
             let thread = TSContactThread.getWithContactId(hexEncodedPublicKey, transaction: transaction), // TODO: Should this be getOrCreate?
             thread.isContactFriend {

SignalServiceKit/src/Loki/Protocol/Sync Messages/SyncMessagesProtocol.swift

@@ -37,14 +37,22 @@ public final class SyncMessagesProtocol : NSObject {
     }
 
     public static func syncAllContacts() -> Promise<Void> {
-        var friends: [SignalAccount] = []
+        // Collect all master devices with which a session has been established. Note that
+        // this is not the same as all master devices with which we're friends.
+        var hepks: Set<String> = []
         TSContactThread.enumerateCollectionObjects { object, _ in
             guard let thread = object as? TSContactThread else { return }
             let hexEncodedPublicKey = thread.contactIdentifier()
             guard thread.isContactFriend && thread.shouldThreadBeVisible && !thread.isSlaveThread else { return }
-            friends.append(SignalAccount(recipientId: hexEncodedPublicKey))
+            hepks.insert(hexEncodedPublicKey)
         }
-        friends.append(SignalAccount(recipientId: getUserHexEncodedPublicKey())) // TODO: Are we sure about this?
+        TSGroupThread.enumerateCollectionObjects { object, _ in
+            guard let group = object as? TSGroupThread, group.groupModel.groupType == .closedGroup,
+                group.shouldThreadBeVisible else { return }
+            hepks.formUnion(group.groupModel.groupMemberIds)
+        }
+        hepks.insert(getUserHexEncodedPublicKey()) // TODO: Are we sure about this?
+        let friends = hepks.map { SignalAccount(recipientId: $0) }
         let syncManager = SSKEnvironment.shared.syncManager
         let promises = friends.chunked(by: 3).map { friends -> Promise<Void> in // TODO: Does this always fit?
             return Promise(syncManager.syncContacts(for: friends)).map { _ in }