Bug 196990 – Parent window's `history.state` is set to `null` when `history.pushState` is called by a child iframe

• Status: NEW
• Component: History

[Atticus White]

Created attachment 367579 [details]
Reproducible script that can be ran on bugs.webkit.org

What happened:
When an `iframe` calls `window.history.pushState`, the parent window's `window.history.state` becomes replaced with a `null` value.


Expected behavior:
The top page's `history.state` should remain untouched.


Steps to reproduce:
1. Give the top page a `history.state` value (eg, call `window.history.pushState({something}, 'something')`)
2. In an iframe, perform `window.history.pushState(...)`
3. In the top page, observe that `history.state` has become set to `null`

Attached is a minimal working example of the problem that can be ran in the JS console on `bugs.webkit.org`

[Atticus White]

Created attachment 367580 [details]
Sample output of reproducible steps

Attached example output of the reproducible script being ran on Safari (undesired result) and Chrome (desired result)

[Atticus White]

*** Bug 196989 has been marked as a duplicate of this bug. ***

[Justas Brazauskas]

Additionally, a test case was submitted to https://github.com/web-platform-tests/wpt/pull/16381, which can also be used to reproduce this case.

Additionally, it appears that this is also the behavior in Safari TP release 79.

[Radar WebKit Bug Importer]

<rdar://problem/50019069>