[Webkit-unassigned] [Bug 184251] New: touchmove bound to the document during a touchstart listener is not cancelable (default cannot be prevented)

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=184251

            Bug ID: 184251
           Summary: touchmove bound to the document during a touchstart
                    listener is not cancelable (default cannot be
                    prevented)
           Product: WebKit
           Version: Safari 11
          Hardware: iPhone / iPad
                OS: iOS 11
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: HTML Events
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: anand.thakker at mapbox.com

Tested on: iOS 11.2.6, 11.3

Steps to reproduce:
1. Create a script that:
 - Adds a `touchstart` listener, `onStart`, to some div `myDiv`.
 - In `onStart`, add a `touchmove` listener, `onMove`, (with `{passive: false}`) to `document`.
 - In `onMove(e)`, call `e.preventDefault()`.
2. Load the page in iOS 11.2.6 or 11.3 and attempt a scroll from within `myDiv`.

Expected result: the page does not scroll.
Actual result: the page scrolls.

Self-contained example: https://gist.github.com/anandthakker/2d0e71924285a845f0c4e6c5fd966234

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20180403/0227a786/attachment-0002.html>