1802938 - beforeunload popup opens

Status: RESOLVED INCOMPLETE

(Core :: DOM: Events, defect, P3)

Description

[infinita740]

Attachment: Firefox popup.png

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:108.0) Gecko/20100101 Firefox/108.0

Steps to reproduce:

1. open this wikipedia image: https://commons.wikimedia.org/w/index.php?title=File:Firefox_logo,_2019.svg&lang=fr&uselang=fr
2. Interract with the page (click in blank space)
3. Try to close the tab

Actual results:

Firefox show 'beforeunload' popup.

This does not happen with firefox 107.0.

Also happens in nightly 109.0a1 and on other sites than French Wikipedia

Expected results:

Nothing/the tab closes without popup

Comment 1

[Peter Magyari (Desktop QA)]

I was able to reproduce this intermittently (1 time out of 25~) on both Firefox Beta 108 and Nightly 109.0a1 but unfortunately I have not found a sure way to reproduce it consistently.

@infinita740, does it occur consistently on your end? If yes, could you please try to run a mozregression in order to find out what caused this?
Here is where you can find it: https://mozilla.github.io/mozregression/

Thank you for reporting!

Comment 2

[infinita740]

Hi, thank you for looking into it.

I used mozregression but could not find a patch responsible so i checked again my initial assumption.

I was wrong, it happens for me with earlier versions (but seemingly less frequently),
after more testing I foud it (maybe?) dependent on network/full loading of the page (the popup is more frequent if I close the tab quickly).

I still feel there is someting weird as these documentations (https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event , https://developer.mozilla.org/en-US/docs/Web/Security/User_activation) are saying that user input is needed (touch, keydown, mousedown/up) but in my testing simply scrolling the page was sufficient to trigger the popup.

You can close the bug as I am not able to reproduce it 100% of the time (if I let the page fully load).

Comment 3

[Kris Maglione [:kmag]]

I don't understand what the problem is. We show the popup because the website is asking us to. I'm not sure what else we should be doing instead?

(In reply to infinita740 from comment #2)

I still feel there is someting weird as these documentations (https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event , https://developer.mozilla.org/en-US/docs/Web/Security/User_activation) are saying that user input is needed (touch, keydown, mousedown/up) but in my testing simply scrolling the page was sufficient to trigger the popup.

How exactly are you scrolling the page? If you are using the scroll wheel or the keyboard, that will send mouse or key events to the page, which counts as user activation. If you're using the scrollbar, it shouldn't.

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:edgar, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 5

[Kris Maglione [:kmag]]

I think this is working as expected