Fix occasional hang on startup

SignalServiceKit/src/Contacts/TSThread.h

@@ -216,6 +216,8 @@ typedef NS_ENUM(NSInteger, LKThreadFriendRequestStatus) {
  */
 - (void)removeOldIncomingFriendRequestMessagesIfNeededWithTransaction:(YapDatabaseReadWriteTransaction *)transaction;
 
+- (TSInteraction *)getLastInteractionWithTransaction:(YapDatabaseReadTransaction *)transaction;
+
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Contacts/TSThread.m

@@ -292,12 +292,17 @@ ConversationColorName const kConversationColorName_Default = ConversationColorNa
 {
     __block TSInteraction *interaction;
     [self.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
-        YapDatabaseViewTransaction *interactions = [transaction ext:TSMessageDatabaseViewExtensionName];
-        interaction = [interactions lastObjectInGroup:self.uniqueId];
+        interaction = [self getLastInteractionWithTransaction:transaction];
     }];
     return interaction;
 }
 
+- (TSInteraction *)getLastInteractionWithTransaction:(YapDatabaseReadTransaction *)transaction
+{
+    YapDatabaseViewTransaction *interactions = [transaction ext:TSMessageDatabaseViewExtensionName];
+    return [interactions lastObjectInGroup:self.uniqueId];
+}
+
 /**
  * Useful for tests and debugging. In production use an enumeration method.
  */

SignalServiceKit/src/Messages/OWSMessageManager.m

@@ -1789,7 +1789,7 @@ NS_ASSUME_NONNULL_BEGIN
     if (thread.friendRequestStatus == LKThreadFriendRequestStatusNone) { return; }
     // Become happy friends and go on great adventures
     [thread saveFriendRequestStatus:LKThreadFriendRequestStatusFriends withTransaction:transaction];
-    TSOutgoingMessage *existingFriendRequestMessage = [thread.lastInteraction as:TSOutgoingMessage.class];
+    TSOutgoingMessage *existingFriendRequestMessage = [[thread getLastInteractionWithTransaction:transaction] as:TSOutgoingMessage.class];
     if (existingFriendRequestMessage != nil && existingFriendRequestMessage.isFriendRequest) {
         [existingFriendRequestMessage saveFriendRequestStatus:LKMessageFriendRequestStatusAccepted withTransaction:transaction];
     }