From b51d935cd17144ace940ecd2a64809e0dd9c1362 Mon Sep 17 00:00:00 2001
From: Lorenzo Miniero <lminiero@gmail.com>
Date: Fri, 10 Jan 2020 11:38:57 +0100
Subject: [PATCH] Use sendBeacon instead of sync XHR in onbeforeunload (fixes
 #1902) (#1918)

---
 html/janus.js | 42 +++++++++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/html/janus.js b/html/janus.js
index bf58e89512..67d5e6f101 100644
--- a/html/janus.js
+++ b/html/janus.js
@@ -327,7 +327,7 @@ Janus.init = function(options) {
 			for(var s in Janus.sessions) {
 				if(Janus.sessions[s] && Janus.sessions[s].destroyOnUnload) {
 					Janus.log("Destroying session " + s);
-					Janus.sessions[s].destroy({asyncRequest: false, notifyDestroyed: false});
+					Janus.sessions[s].destroy({unload: true, notifyDestroyed: false});
 				}
 			}
 			if(oldOBF && typeof oldOBF == "function")
@@ -949,16 +949,12 @@ function Janus(gatewayCallbacks) {
 		callbacks = callbacks || {};
 		// FIXME This method triggers a success even when we fail
 		callbacks.success = (typeof callbacks.success == "function") ? callbacks.success : Janus.noop;
-		var asyncRequest = true;
-		if(callbacks.asyncRequest !== undefined && callbacks.asyncRequest !== null)
-			asyncRequest = (callbacks.asyncRequest === true);
+		var unload = (callbacks.unload === true);
 		var notifyDestroyed = true;
 		if(callbacks.notifyDestroyed !== undefined && callbacks.notifyDestroyed !== null)
 			notifyDestroyed = (callbacks.notifyDestroyed === true);
-		var cleanupHandles = false;
-		if(callbacks.cleanupHandles !== undefined && callbacks.cleanupHandles !== null)
-			cleanupHandles = (callbacks.cleanupHandles === true);
-		Janus.log("Destroying session " + sessionId + " (async=" + asyncRequest + ")");
+		var cleanupHandles = (callbacks.cleanupHandles === true);
+		Janus.log("Destroying session " + sessionId + " (unload=" + unload + ")");
 		if(!sessionId) {
 			Janus.warn("No session to destroy");
 			callbacks.success();
@@ -972,6 +968,7 @@ function Janus(gatewayCallbacks) {
 		}
 		if(!connected) {
 			Janus.warn("Is the server down? (connected=false)");
+			sessionId = null;
 			callbacks.success();
 			return;
 		}
@@ -981,6 +978,24 @@ function Janus(gatewayCallbacks) {
 			request["token"] = token;
 		if(apisecret)
 			request["apisecret"] = apisecret;
+		if(unload) {
+			// We're unloading the page: use sendBeacon for HTTP instead,
+			// or just close the WebSocket connection if we're using that
+			if(websockets) {
+				ws.onclose = null;
+				ws.close();
+				ws = null;
+			} else {
+				navigator.sendBeacon(server + "/" + sessionId, JSON.stringify(request));
+			}
+			Janus.log("Destroyed session:");
+			sessionId = null;
+			connected = false;
+			callbacks.success();
+			if(notifyDestroyed)
+				gatewayCallbacks.destroyed();
+			return;
+		}
 		if(websockets) {
 			request["session_id"] = sessionId;
 
@@ -1020,7 +1035,6 @@ function Janus(gatewayCallbacks) {
 		}
 		Janus.httpAPICall(server + "/" + sessionId, {
 			verb: 'POST',
-			async: asyncRequest,	// Sometimes we need false here, or destroying in onbeforeunload won't work
 			withCredentials: withCredentials,
 			body: request,
 			success: function(json) {
@@ -1548,13 +1562,8 @@ function Janus(gatewayCallbacks) {
 		callbacks = callbacks || {};
 		callbacks.success = (typeof callbacks.success == "function") ? callbacks.success : Janus.noop;
 		callbacks.error = (typeof callbacks.error == "function") ? callbacks.error : Janus.noop;
-		var asyncRequest = true;
-		if(callbacks.asyncRequest !== undefined && callbacks.asyncRequest !== null)
-			asyncRequest = (callbacks.asyncRequest === true);
-		var noRequest = true;
-		if(callbacks.noRequest !== undefined && callbacks.noRequest !== null)
-			noRequest = (callbacks.noRequest === true);
-		Janus.log("Destroying handle " + handleId + " (async=" + asyncRequest + ")");
+		var noRequest = (callbacks.noRequest === true);
+		Janus.log("Destroying handle " + handleId + " (only-locally=" + noRequest + ")");
 		cleanupWebrtc(handleId);
 		var pluginHandle = pluginHandles[handleId];
 		if(!pluginHandle || pluginHandle.detached) {
@@ -1589,7 +1598,6 @@ function Janus(gatewayCallbacks) {
 		}
 		Janus.httpAPICall(server + "/" + sessionId + "/" + handleId, {
 			verb: 'POST',
-			async: asyncRequest,	// Sometimes we need false here, or destroying in onbeforeunload won't work
 			withCredentials: withCredentials,
 			body: request,
 			success: function(json) {