Bug 281175 – Using Cross-Origin-Opener-Policy HTTP header may corrupt the back/forward list

• Component: WebKit2
• Status: RESOLVED FIXED

[Chris Dumez]

Using Cross-Origin-Opener-Policy HTTP header may corrupt the back/forward list:
```
Got a better repro (thanks to a colleague, David Taylor). 

https://d5.musaraj.com and https://d6.musaraj.com are identical, but d5 has the COOP header, d6 doesn't. The HTML for both is: 

```
<ol>
<li><button onclick="window.history.pushState({}, null, '/foo')">Click me</button></li>
<li>Use browser to go 'back' one step</li>
<li><a href="https://d4.musaraj.com">Then click me</a></li>
</ol>
```

https://d4.musaraj.com has this HTML: 

```
<script>document.write(`window.location is ${window.location}`)</script>
```

Can see that window history gets corrupted with steps followed in d5 but not with d6.
```

[Radar WebKit Bug Importer]

<rdar://problem/137635838>

[Chris Dumez]

This is a follow-up to Bug 274310 as it still appears to be broken.

[Chris Dumez]

I have a fix (actually 2 ways one more complete but a bit more risky and another very limited but safe). I'm working on a test now.

[Chris Dumez]

Pull request: https://github.com/WebKit/WebKit/pull/35657

[EWS]

Committed 285729@main (2b008f6776a2): <https://commits.webkit.org/285729@main>

Reviewed commits have been landed. Closing PR #35657 and removing active labels.

[EWS]

Committed 283286.449@safari-7620-branch (1b35def6ef77): <https://commits.webkit.org/283286.449@safari-7620-branch>

Reviewed commits have been landed. Closing PR #2240 and removing active labels.

[Penar Musaraj]

I can still repro this issue on latest Safari TP, release 207. 

I cannot reproduce it on an early archive build, 285848@main from October 29.