[Bug]: Firefox delivers other pages' mouse events to a page that captured the pointer #43631

import { chromium, firefox, webkit } from 'playwright';

const logEvents = `
  window.events = [];
  for (const type of ['pointerdown', 'pointerup', 'click']) {
    document.addEventListener(type, () => window.events.push(type));
  }
`;

for (const browserType of [chromium, firefox, webkit]) {
  const browser = await browserType.launch();
  const capturing = await browser.newPage();
  const clicked = await browser.newPage();

  await capturing.setContent(`
    <div id="handle" style="width: 200px; height: 200px; background: red"></div>
    <script>
      ${logEvents}
      handle.addEventListener('pointerdown', (event) => handle.setPointerCapture(event.pointerId));
    </script>
  `);
  await clicked.setContent(`
    <button style="width: 200px; height: 200px">click me</button>
    <script>${logEvents}</script>
  `);

  // press the mouse on the handle of the first page, which captures the pointer
  await capturing.mouse.move(100, 100);
  await capturing.mouse.down();

  // click the second page, in another context, 3 times
  for (let i = 0; i < 3; i++) {
    await clicked.mouse.click(100, 100);
  }

  await capturing.mouse.up();

  console.log(`${browserType.name()}:`);
  console.log(`  first page:  ${(await capturing.evaluate(() => window.events)).join(', ')}`);
  console.log(`  second page: ${(await clicked.evaluate(() => window.events)).join(', ')}`);

  await browser.close();
}