Correctly dereference stored images when leaving channels

Fixes #1404

src/client.js

@@ -488,6 +488,8 @@ Client.prototype.quit = function() {
 		if (network.irc) {
 			network.irc.quit("Page closed");
 		}
+
+		network.destroy();
 	});
 };
 

src/models/chan.js

@@ -30,6 +30,10 @@ function Chan(attr) {
 	});
 }
 
+Chan.prototype.destroy = function() {
+	this.dereferencePreviews(this.messages);
+};
+
 Chan.prototype.pushMessage = function(client, msg, increasesUnread) {
 	var obj = {
 		chan: this.id,
@@ -56,12 +60,10 @@ Chan.prototype.pushMessage = function(client, msg, increasesUnread) {
 	if (Helper.config.maxHistory >= 0 && this.messages.length > Helper.config.maxHistory) {
 		const deleted = this.messages.splice(0, this.messages.length - Helper.config.maxHistory);
 
-		if (Helper.config.prefetch && Helper.config.prefetchStorage) {
-			deleted.forEach((deletedMessage) => {
-				if (deletedMessage.preview && deletedMessage.preview.thumb) {
-					storage.dereference(deletedMessage.preview.thumb);
-				}
-			});
+		// If maxHistory is 0, image would be dereferenced before client had a chance to retrieve it,
+		// so for now, just don't implement dereferencing for this edge case.
+		if (Helper.config.prefetch && Helper.config.prefetchStorage && Helper.config.maxHistory > 0) {
+			this.dereferencePreviews(deleted);
 		}
 	}
 
@@ -76,6 +78,15 @@ Chan.prototype.pushMessage = function(client, msg, increasesUnread) {
 	}
 };
 
+Chan.prototype.dereferencePreviews = function(messages) {
+	messages.forEach((message) => {
+		if (message.preview && message.preview.thumb) {
+			storage.dereference(message.preview.thumb);
+			message.preview.thumb = null;
+		}
+	});
+};
+
 Chan.prototype.sortUsers = function(irc) {
 	var userModeSortPriority = {};
 	irc.network.options.PREFIX.forEach((prefix, index) => {

src/models/network.js

@@ -42,6 +42,10 @@ function Network(attr) {
 	);
 }
 
+Network.prototype.destroy = function() {
+	this.channels.forEach((channel) => channel.destroy());
+};
+
 Network.prototype.setNick = function(nick) {
 	this.nick = nick;
 	this.highlightRegex = new RegExp(

src/plugins/inputs/part.js

@@ -17,6 +17,7 @@ exports.input = function(network, chan, cmd, args) {
 	}
 
 	network.channels = _.without(network.channels, chan);
+	chan.destroy();
 	this.emit("part", {
 		chan: chan.id
 	});

src/plugins/inputs/quit.js

@@ -11,6 +11,7 @@ exports.input = function(network, chan, cmd, args) {
 	var quitMessage = args[0] ? args.join(" ") : "";
 
 	client.networks = _.without(client.networks, network);
+	network.destroy();
 	client.save();
 	client.emit("quit", {
 		network: network.id

src/plugins/irc-events/part.js

@@ -13,6 +13,7 @@ module.exports = function(irc, network) {
 		var from = data.nick;
 		if (from === irc.user.nick) {
 			network.channels = _.without(network.channels, chan);
+			chan.destroy();
 			client.save();
 			client.emit("part", {
 				chan: chan.id

src/plugins/storage.js

@@ -17,12 +17,6 @@ class Storage {
 	}
 
 	dereference(url) {
-		// If maxHistory is 0, image would be dereferenced before client had a chance to retrieve it,
-		// so for now, just don't implement dereferencing for this edge case.
-		if (helper.maxHistory === 0) {
-			return;
-		}
-
 		const references = (this.references.get(url) || 0) - 1;
 
 		if (references < 0) {