Bug 246313

Summary: The second pointerdown/touchstart event is missing on double-tap gesture
Product: WebKit Reporter: weijarz
Component: UI EventsAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: thorton, webkit-bug-importer, wenson_hsieh
Priority: P2 Keywords: InRadar
Version: Safari 16   
Hardware: iPhone / iPad   
OS: iOS 16   

Description weijarz 2022-10-10 19:39:17 PDT 
To reproduce:

https://www.oxyry.com/test/safari-double-tap-bug/safari-double-tap-bug.html

1. Open the url in safari
2. Add this webpage to Home Screen (REQUIRED!!!)
3. Open this webpage from Home Screen icon.
4. Double tap black area, only one pointerdown/touchstart event will be triggered!

Note: Open it in Safari browser is working properly.


Full source:
```
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=0">
    <title>Safari double tap bug</title>

    <link rel="manifest" href="manifest.json">

    <meta name="apple-mobile-web-app-capable" content="yes">
    <meta name="mobile-web-app-capable" content="yes">
    <meta name="apple-mobile-web-app-status-bar-style" content="default">

    <style>
      #rootEl {
        height: 70vh;
        overflow: auto;
        background: #000;
        color: #fff;
        /* touch-action: none; */
        user-select: none;
      }
    </style>
  </head>
  <body>
    <div>
      <div id="rootEl"></div>
      <p id="btns">
        <button id="clearBtn">Clear</button>
        <button id="reloadBtn">Reload</button>
      </p>
    </div>
    <script>
      clearBtn.onclick = () => { rootEl.innerHTML = ''; }
      reloadBtn.onclick =  () => { location.reload(); }

      const log = (msg) => {
        const m = document.createElement('div')
        m.textContent = msg
        rootEl.appendChild(m)
      }

      let i = 0
      rootEl.addEventListener('pointerdown', () => {
        log(`pointerdown #${i++}`)
      })

      let j = 0
      rootEl.addEventListener('touchstart', (ev) => {
        log(`touchstart #${j++}`)
        // ev.preventDefault()
      })
    </script>
  </body>
</html>

```
Comment 1 Radar WebKit Bug Importer 2022-10-17 19:40:18 PDT 
<rdar://problem/101273397>
Comment 2 Richard Robinson 2022-11-03 14:39:46 PDT 
Pull request: https://github.com/WebKit/WebKit/pull/6101
Comment 3 EWS 2022-11-04 20:34:16 PDT 
Committed 256348@main (6115b3860098): <https://commits.webkit.org/256348@main>

Reviewed commits have been landed. Closing PR #6101 and removing active labels.