1875028 - With Fission enabled "onbeforeunload" prompts are automatically accepted for cross-origin navigations

Status: VERIFIED FIXED

(Core :: DOM: Navigation, defect)

Description

[Henrik Skupin [:whimboo][⌚️UTC+2]]

On web pages that have setup a "beforeunload" handler a navigation as initiated by entering the URL into the location bar will automatically accept the prompt and continues with the navigation to the expected target web page.

Steps to reproduce:

1. Start Firefox
2. Open https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event#examples
3. Scroll a bit down and enter some text into the input field of the playground example
4. Focus the location bar and navigate to example.org

As it can be seen the beforeunload prompt is shown for a split of a second. Then it's automatically accepted and the navigation continues not leaving the user the chance to select Stay on page.

Note that when using the back and forward buttons from the toolbar the dialog is correctly shown. Also with Fission turned off this behavior cannot be seen.

Comment 1

[Peter Van der Beken [:peterv]]

I have this in a pernosco recording. Looks weird.

https://pernos.co/debug/8ht0xGyYFr1NeFqTIKvCZQ/index.html#f{m[Ayrd,CHP6_,t[2w,HzRp_,f{e[Ayrd,CHPu_,s{afzx/k5AA,bAZg,uD8ujWw,oD9I42g___/

Comment 2

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Hi Peter. I wanted to ask if you have an update for this bug. Thanks.

Comment 3

[Peter Van der Beken [:peterv]]

Attachment: Bug 1875028 - With Fission enabled "onbeforeunload" prompts are automatically accepted for cross-origin navigations. r=farre!

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/12f463440a22
With Fission enabled "onbeforeunload" prompts are automatically accepted for cross-origin navigations. r=farre

Comment 5

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/12f463440a22

Comment 6

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Thanks! It works fine now.