Automatically load recent messages on reconnect (#3878)

* Add working reconnect recent messages

* Rename method to messagesUpdated

* Use audo declarations

* Add docs to new LimitedQueue methods

* Add more documentation, try atomic loading flag

* Update CHANGELOG.md

* Remove unused include

* Rename 'reconnected' signal to 'connected'

* Reserve before filtering on arbitrary update

* Extract recent messages fetching to own class

* Use std::atomic_flag instead of std::atomic_bool

* Add PostToThread include

* Add chatterino.recentmessages logging

* Remove unneeded parameters, lambda move capture

* Remove TwitchChannel::buildRecentMessages

* Add documentation, use more clear method name

* Reword changelog entry

I think it sounds better like this :)

* Rework how filling in missing messages is handled

This should hopefully prevent issues with filtered channels with old messages
that no longer exist in the underlying channel

* Check existing messages when looking for reply

* Clean up string distribution in file

* Try to improve documentation

* Use std::function for RecentMessagesApi

* Only trigger filledInMessages if we inserted

* Remove old unused lines

* Use make_shared<MessageLayout> instead of new MessageLayout

* Alphabetize QLogging categories

* Reorder CHANGELOG.md

src/providers/twitch/IrcMessageHandler.cpp

@@ -304,6 +304,8 @@ void IrcMessageHandler::populateReply(
             }
         }
 
+        MessagePtr foundMessage;
+
         // Thread does not yet exist, find root reply and create thread.
         // Linear search is justified by the infrequent use of replies
         for (auto &otherMsg : otherLoaded)
@@ -311,15 +313,29 @@ void IrcMessageHandler::populateReply(
             if (otherMsg->id == replyID)
             {
                 // Found root reply message
-                std::shared_ptr<MessageThread> newThread =
-                    std::make_shared<MessageThread>(otherMsg);
-
-                builder.setThread(newThread);
-                // Store weak reference to thread in channel
-                channel->addReplyThread(newThread);
+                foundMessage = otherMsg;
                 break;
             }
         }
+
+        if (!foundMessage)
+        {
+            // We didn't find the reply root message in the otherLoaded messages
+            // which are typically the already-parsed recent messages from the
+            // Recent Messages API. We could have a really old message that
+            // still exists being replied to, so check for that here.
+            foundMessage = channel->findMessage(replyID);
+        }
+
+        if (foundMessage)
+        {
+            std::shared_ptr<MessageThread> newThread =
+                std::make_shared<MessageThread>(foundMessage);
+
+            builder.setThread(newThread);
+            // Store weak reference to thread in channel
+            channel->addReplyThread(newThread);
+        }
     }
 }