From 1ca16816c2cceaccc89d165d866473f5b358f97c Mon Sep 17 00:00:00 2001
From: Pavel Djundik <xPaw@users.noreply.github.com>
Date: Thu, 17 Oct 2019 13:53:29 +0300
Subject: [PATCH] Synchronize open channel on client on reconnection

---
 client/js/socket-events/auth.js | 12 ++++++++----
 src/server.js                   | 20 ++++++++++++++++----
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/client/js/socket-events/auth.js b/client/js/socket-events/auth.js
index 6ce7e47c..3fd5e66d 100644
--- a/client/js/socket-events/auth.js
+++ b/client/js/socket-events/auth.js
@@ -79,15 +79,19 @@ socket.on("auth", function(data) {
 
 			for (const network of vueApp.networks) {
 				for (const chan of network.channels) {
-					for (const msg of chan.messages) {
-						if (msg.id > lastMessage) {
-							lastMessage = msg.id;
+					if (chan.messages.length > 0) {
+						const id = chan.messages[chan.messages.length - 1].id;
+
+						if (lastMessage < id) {
+							lastMessage = id;
 						}
 					}
 				}
 			}
 
-			socket.emit("auth", {user, token, lastMessage});
+			const openChannel = (vueApp.activeChannel && vueApp.activeChannel.channel.id) || null;
+
+			socket.emit("auth", {user, token, lastMessage, openChannel});
 		}
 	}
 
diff --git a/src/server.js b/src/server.js
index 38f2e05b..51ea8d87 100644
--- a/src/server.js
+++ b/src/server.js
@@ -331,11 +331,23 @@ function indexRequest(req, res) {
 	);
 }
 
-function initializeClient(socket, client, token, lastMessage) {
+function initializeClient(socket, client, token, lastMessage, openChannel) {
 	socket.emit("authorized");
 
 	client.clientAttach(socket.id, token);
 
+	// Client sends currently active channel on reconnect,
+	// pass it into `open` directly so it is verified and updated if necessary
+	if (openChannel) {
+		client.open(socket.id, openChannel);
+
+		// If client provided channel passes checks, use it. if client has invalid
+		// channel open (or windows like settings) then use last known server active channel
+		openChannel = client.attachedClients[socket.id].openChannel || client.lastActiveChannel;
+	} else {
+		openChannel = client.lastActiveChannel;
+	}
+
 	if (Helper.config.fileUpload.enable) {
 		new Uploader(socket);
 	}
@@ -624,9 +636,9 @@ function initializeClient(socket, client, token, lastMessage) {
 		socket.emit("init", {
 			applicationServerKey: manager.webPush.vapidKeys.publicKey,
 			pushSubscription: client.config.sessions[token],
-			active: client.lastActiveChannel,
+			active: openChannel,
 			networks: client.networks.map((network) =>
-				network.getFilteredClone(client.lastActiveChannel, lastMessage)
+				network.getFilteredClone(openChannel, lastMessage)
 			),
 			token: tokenToSend,
 		});
@@ -705,7 +717,7 @@ function performAuthentication(data) {
 	let token = null;
 
 	const finalInit = () => {
-		initializeClient(socket, client, token, data.lastMessage || -1);
+		initializeClient(socket, client, token, data.lastMessage || -1, data.openChannel);
 
 		if (!Helper.config.public) {
 			client.manager.updateUser(client.name, {