Fix simultaneous session request bug

Signal.xcodeproj/xcshareddata/xcschemes/Signal.xcscheme

@@ -126,6 +126,9 @@
                <Test
                   Identifier = "OWSSignalAddressTest">
                </Test>
+               <Test
+                  Identifier = "OWSUDManagerTest">
+               </Test>
                <Test
                   Identifier = "PhoneNumberTest">
                </Test>

SignalServiceKit/src/Loki/Database/OWSPrimaryStorage+Loki.swift

@@ -1,6 +1,18 @@
 
 public extension OWSPrimaryStorage {
 
+    // MARK: Session Requests
+    private static let sessionRequestTimestampCollection = "LokiSessionRequestTimestampCollection"
+
+    public func setSessionRequestTimestamp(for publicKey: String, to timestamp: Date, in transaction: YapDatabaseReadWriteTransaction) {
+        transaction.setDate(timestamp, forKey: publicKey, inCollection: OWSPrimaryStorage.sessionRequestTimestampCollection)
+    }
+
+    public func getSessionRequestTimestamp(for publicKey: String, in transaction: YapDatabaseReadTransaction) -> Date? {
+        transaction.date(forKey: publicKey, inCollection: OWSPrimaryStorage.sessionRequestTimestampCollection)
+    }
+
+    // MARK: Multi Device
     private static var deviceLinkCache: Set<DeviceLink> = []
 
     private func getDeviceLinkCollection(for masterHexEncodedPublicKey: String) -> String {
@@ -62,7 +74,8 @@ public extension OWSPrimaryStorage {
     public func getMasterHexEncodedPublicKey(for slaveHexEncodedPublicKey: String, in transaction: YapDatabaseReadTransaction) -> String? {
         return getDeviceLink(for: slaveHexEncodedPublicKey, in: transaction)?.master.hexEncodedPublicKey
     }
-    
+
+    // MARK: Open Groups
     public func getUserCount(for publicChat: LokiPublicChat, in transaction: YapDatabaseReadTransaction) -> Int? {
         return transaction.object(forKey: publicChat.id, inCollection: "LokiPublicChatUserCountCollection") as? Int
     }

SignalServiceKit/src/Loki/Protocol/Closed Groups/ClosedGroupsProtocol.swift

@@ -41,9 +41,10 @@ public final class ClosedGroupsProtocol : NSObject {
             let thread = TSContactThread.getOrCreateThread(withContactId: hexEncodedPublicKey, transaction: transaction)
             thread.save(with: transaction)
             let sessionRequestMessage = SessionRequestMessage(thread: thread)
+            storage.setSessionRequestTimestamp(for: hexEncodedPublicKey, to: Date(), in: transaction)
             let messageSenderJobQueue = SSKEnvironment.shared.messageSenderJobQueue
             // This has to happen sync to ensure that session requests get sent before AFRs do (it's
-            // asssumed that the master device first syncs closed groups first and contacts after that).
+            // asssumed that the master device syncs closed groups first and contacts after that).
             messageSenderJobQueue.add(message: sessionRequestMessage, transaction: transaction)
         }
     }

SignalServiceKit/src/Loki/Protocol/Meta/SessionMetaProtocol.swift

@@ -55,7 +55,6 @@ public final class SessionMetaProtocol : NSObject {
     }
 
     // MARK: Note to Self
-
     @objc(isThreadNoteToSelf:)
     public static func isThreadNoteToSelf(_ thread: TSThread) -> Bool {
         guard let thread = thread as? TSContactThread else { return false }

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

@@ -145,6 +145,7 @@ public final class SessionManagementProtocol : NSObject {
             storage.dbReadWriteConnection.readWrite { transaction in
                 let thread = TSContactThread.getOrCreateThread(withContactId: hexEncodedPublicKey, transaction: transaction)
                 let sessionRequestMessage = SessionRequestMessage(thread: thread)
+                storage.setSessionRequestTimestamp(for: hexEncodedPublicKey, to: Date(), in: transaction)
                 let messageSenderJobQueue = SSKEnvironment.shared.messageSenderJobQueue
                 messageSenderJobQueue.add(message: sessionRequestMessage, transaction: transaction)
             }
@@ -192,6 +193,11 @@ public final class SessionManagementProtocol : NSObject {
     public static func handleSessionRequestMessage(_ dataMessage: SSKProtoDataMessage, wrappedIn envelope: SSKProtoEnvelope, using transaction: YapDatabaseReadWriteTransaction) {
         // The envelope source is set during UD decryption
         let hexEncodedPublicKey = envelope.source!
+        if let sentSessionRequestTimestamp = storage.getSessionRequestTimestamp(for: hexEncodedPublicKey, in: transaction),
+            envelope.timestamp < NSDate.ows_millisecondsSince1970(for: sentSessionRequestTimestamp) {
+            // We sent a session request after this one was sent
+            return
+        }
         var closedGroupMembers: Set<String> = []
         TSGroupThread.enumerateCollectionObjects(with: transaction) { object, _ in
             guard let group = object as? TSGroupThread, group.groupModel.groupType == .closedGroup,