Update friend request auto-acceptance for multi device

SignalServiceKit/src/Messages/OWSMessageManager.m

@@ -1534,13 +1534,8 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
-- (void)handleFriendRequestMessageIfNeededWithEnvelope:(SSKProtoEnvelope *)envelope data:(SSKProtoDataMessage *)data message:(TSIncomingMessage *)message thread:(TSThread *)thread transaction:(YapDatabaseReadWriteTransaction *)transaction {
+- (BOOL)canFriendRequestBeAutoAcceptedForThread:(TSContactThread *)thread transaction:(YapDatabaseReadWriteTransaction *)transaction
-    if (envelope.isGroupChatMessage) {
+{
-        return NSLog(@"[Loki] Ignoring friend request in group chat.", @"");
-    }
-    if (envelope.type != SSKProtoEnvelopeTypeFriendRequest) {
-        return NSLog(@"[Loki] handleFriendRequestMessageIfNeededWithEnvelope:data:message:thread:transaction was called with an envelope that isn't of type SSKProtoEnvelopeTypeFriendRequest.");
-    }
     if (thread.hasCurrentUserSentFriendRequest) {
         // This can happen if Alice sent Bob a friend request, Bob declined, but then Bob changed his
         // mind and sent a friend request to Alice. In this case we want Alice to auto-accept the request
@@ -1552,16 +1547,60 @@ NS_ASSUME_NONNULL_BEGIN
         // before updating Alice's thread's friend request status to LKThreadFriendRequestStatusFriends,
         // we can end up in a deadlock where both users' threads' friend request statuses are
         // LKThreadFriendRequestStatusRequestSent.
+        return YES;
+    }
+    NSString *senderHexEncodedPublicKey = thread.contactIdentifier;
+    NSString *userHexEncodedPublicKey = OWSIdentityManager.sharedManager.identityKeyPair.hexEncodedPublicKey;
+    NSString *userMasterHexEncodedPublicKey = [LKDatabaseUtilities getMasterHexEncodedPublicKeyFor:userHexEncodedPublicKey in:transaction];
+    NSMutableSet<NSString *> *userLinkedDeviceHexEncodedPublicKeys = [NSMutableSet new];
+    NSSet<LKDeviceLink *> *userDeviceLinks = [LKDatabaseUtilities getDeviceLinksFor:userMasterHexEncodedPublicKey in:transaction];
+    for (LKDeviceLink *deviceLink in userDeviceLinks) {
+        [userLinkedDeviceHexEncodedPublicKeys addObject:deviceLink.master.hexEncodedPublicKey];
+        [userLinkedDeviceHexEncodedPublicKeys addObject:deviceLink.slave.hexEncodedPublicKey];
+    }
+    if ([userLinkedDeviceHexEncodedPublicKeys containsObject:senderHexEncodedPublicKey]) {
+        // Auto-accept any friend requests from the user's own linked devices
+        return YES;
+    }
+    NSString *senderMasterHexEncodedPublicKey = [LKDatabaseUtilities getMasterHexEncodedPublicKeyFor:senderHexEncodedPublicKey in:transaction];
+    NSMutableSet<TSContactThread *> *senderLinkedDeviceThreads = [NSMutableSet new];
+    NSSet<LKDeviceLink *> *senderDeviceLinks = [LKDatabaseUtilities getDeviceLinksFor:senderMasterHexEncodedPublicKey in:transaction];
+    for (LKDeviceLink *deviceLink in senderDeviceLinks) {
+        [senderLinkedDeviceThreads addObject:[TSContactThread getThreadWithContactId:deviceLink.master.hexEncodedPublicKey transaction:transaction]];
+        [senderLinkedDeviceThreads addObject:[TSContactThread getThreadWithContactId:deviceLink.slave.hexEncodedPublicKey transaction:transaction]];
+    }
+    if ([senderLinkedDeviceThreads contains:^BOOL(NSObject *object) {
+        TSContactThread *thread = (TSContactThread *)object;
+        return thread.isContactFriend;
+    }]) {
+        // Auto-accept if the user is friends with any of the sender's linked devices.
+        return YES;
+    }
+    return NO;
+}
+
+- (void)handleFriendRequestMessageIfNeededWithEnvelope:(SSKProtoEnvelope *)envelope data:(SSKProtoDataMessage *)data message:(TSIncomingMessage *)message thread:(TSContactThread *)thread transaction:(YapDatabaseReadWriteTransaction *)transaction {
+    if (envelope.isGroupChatMessage) {
+        return NSLog(@"[Loki] Ignoring friend request in group chat.", @"");
+    }
+    if (envelope.type != SSKProtoEnvelopeTypeFriendRequest) {
+        return NSLog(@"[Loki] handleFriendRequestMessageIfNeededWithEnvelope:data:message:thread:transaction was called with an envelope that isn't of type SSKProtoEnvelopeTypeFriendRequest.");
+    }
+    if ([self canFriendRequestBeAutoAcceptedForThread:thread transaction:transaction]) {
         [thread saveFriendRequestStatus:LKThreadFriendRequestStatusFriends withTransaction:transaction];
-        TSOutgoingMessage *existingFriendRequestMessage = (TSOutgoingMessage *)[thread.lastInteraction as:TSOutgoingMessage.class];
+        __block TSOutgoingMessage *existingFriendRequestMessage;
-        if (existingFriendRequestMessage != nil && existingFriendRequestMessage.isFriendRequest) {
+        [thread enumerateInteractionsWithTransaction:transaction usingBlock:^(TSInteraction *interaction, YapDatabaseReadTransaction *transaction) {
+            if ([interaction isKindOfClass:TSOutgoingMessage.class] && ((TSOutgoingMessage *)interaction).isFriendRequest) {
+                existingFriendRequestMessage = (TSOutgoingMessage *)interaction;
+            }
+        }];
+        if (existingFriendRequestMessage != nil) {
             [existingFriendRequestMessage saveFriendRequestStatus:LKMessageFriendRequestStatusAccepted withTransaction:transaction];
         }
         // The two lines below are equivalent to calling [ThreadUtil enqueueFriendRequestAcceptanceMessageInThread:thread]
         LKEphemeralMessage *backgroundMessage = [[LKEphemeralMessage alloc] initInThread:thread];
         [self.messageSenderJobQueue addMessage:backgroundMessage transaction:transaction];
-    } else {
+    } else if (!thread.isContactFriend) {
-        if (!thread.isContactFriend) {
         // Checking that the sender of the message isn't already a friend is necessary because otherwise
         // the following situation can occur: Alice and Bob are friends. Bob loses his database and his
         // friend request status is reset to LKThreadFriendRequestStatusNone. Bob now sends Alice a friend
@@ -1597,7 +1636,6 @@ NS_ASSUME_NONNULL_BEGIN
 //        [self handleEndSessionMessageWithEnvelope:envelope dataMessage:data transaction:transaction];
     }
 }
-}
 
 - (void)handleFriendRequestAcceptanceIfNeededWithEnvelope:(SSKProtoEnvelope *)envelope transaction:(YapDatabaseReadWriteTransaction *)transaction {
     // If we get an envelope that isn't a friend request, then we can infer that we had to use