When a guest detaches from an embedder (e.g. a window's WebContents),…

… stop forwarding events to the embedder

Fix #515

lib/browser/guest-view-manager.js

@@ -45,6 +45,7 @@ let supportedWebViewEvents = [
 ]
 
 let guests = {}
+// ensure webcontent events (from guest) are fired to embedder (window) so they can be forwarded to webview / interested-party
 const registerGuest = function (guest, embedder) {
   const tabId = guest.getId()
 
@@ -61,8 +62,9 @@ const registerGuest = function (guest, embedder) {
   }
 
   // Dispatch events to embedder.
-  const fn = function (event) {
-    guest.on(event, function (_, ...args) {
+  const guestHandlersThisEmbedder = { }
+  for (const event of supportedWebViewEvents) {
+    guestHandlersThisEmbedder[event] = function (_, ...args) {
       const embedder = guests[tabId]
 
       if (!embedder || embedder.isDestroyed())
@@ -73,16 +75,21 @@ const registerGuest = function (guest, embedder) {
         delete guests[tabId]
         forceSend = true
       }
+      if (event === 'did-detach') {
+        for (const event in guestHandlersThisEmbedder) {
+          guest.removeListener(event, guestHandlersThisEmbedder[event])
+        }
+      }
 
       if (guest.isDestroyed() && !forceSend)
         return
 
       embedder.send.apply(embedder, ['ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT', tabId, event].concat(args))
-    })
-  }
-  for (const event of supportedWebViewEvents) {
-    fn(event)
+    }
+    guest.on(event, guestHandlersThisEmbedder[event])
   }
+
+
 
   // Dispatch guest's IPC messages to embedder.
   guest.on('ipc-message-host', function (_, [channel, ...args]) {