Fix jitsi widget popout (#30908)

* Fix jitsi widget popout

Unfortunately I don't think playwright or jest can write a test for
something successfully opening a new tab.

Fixes https://github.com/element-hq/element-desktop/issues/2527

* On second thoughts, this is probably overkill

* Clarify

* Add test

* Unused import

playwright/e2e/widgets/jitsi.spec.ts

@@ -0,0 +1,51 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { test as base, expect } from "../../element-web-test";
+import { Bot } from "../../pages/bot";
+
+const ROOM_NAME = "Jitsi Room";
+
+const test = base.extend<{
+    bot1: Bot;
+    bot2: Bot;
+}>({
+    bot2: async ({ page, homeserver }, use, testInfo) => {
+        const bot = new Bot(page, homeserver, { displayName: `ByteBot_${testInfo.testId}` });
+        await bot.prepareClient(); // eagerly register the bot
+        await use(bot);
+    },
+});
+
+test.describe("Jitsi Calls", () => {
+    test.use({
+        displayName: "Jimmy",
+        botCreateOpts: { displayName: "Bot", autoAcceptInvites: false },
+    });
+
+    test("should be able to pop out a jitsi widget", async ({ page, app, bot, bot2, context }) => {
+        const roomId = await app.client.createRoom({
+            name: ROOM_NAME,
+            invite: [bot.credentials.userId, bot2.credentials.userId],
+        });
+
+        await bot.joinRoom(roomId);
+        await bot2.joinRoom(roomId);
+
+        // open the room
+        await app.viewRoomByName(ROOM_NAME);
+
+        await page.getByRole("button", { name: "Video call" }).click();
+
+        const pagePromise = context.waitForEvent("page");
+
+        await page.getByRole("button", { name: "Popout widget" }).click();
+
+        const newPage = await pagePromise;
+        await expect(newPage.getByRole("button", { name: "Join Conference" })).toBeVisible();
+    });
+});

src/components/views/elements/AppTile.tsx

@@ -476,6 +476,8 @@ export default class AppTile extends React.Component<IProps, IState> {
         }
 
         // Delete the widget from the persisted store for good measure.
+        // XXX: This removes persistent elements from the DOM entirely, which feels like
+        // a lot more than this function claims to be doing.
         PersistedElement.destroyElement(this.persistKey);
         ActiveWidgetStore.instance.destroyPersistentWidget(
             this.props.app.id,
@@ -586,7 +588,7 @@ export default class AppTile extends React.Component<IProps, IState> {
         // reset messaging
         this.resetWidget(this.props);
         this.iframeParent?.querySelector("iframe")?.remove();
-        this.startMessaging();
+        // iframeParent will now be re-mounted, at which point startMessaging will be called
     }
 
     // TODO replace with full screen interactions