warning dialog when closing multiple private tabs can become unresponsive

[hbchoong]

Affecting Firefox 60 with Ubuntu 18.04.1: (Private Browsing)

When closing down Private Browsing with 2 tabs or more, the 'warning' dialog box appears but if no selection is made after a while, the 'Gnome' dialog box appears behind it incorrectly indicating Firefox is 'unresponsive'. This causes the application to freeze as no selection can then be made as the 'Gnome' dialog box's selection is hidden (inactive window) behind Firefox's 'warning' dialog box (active window) which has now frozen (...awaiting the 'Gnome' dialog box's selection which cannot be made!)

Thank you for passing this on to the appropriate teams for action.

[hbchoong (hbchoong)]

Issue is still evident and remains the same with the latest Firefox 62...

[Olivier Tilloy (osomon)]

Please file separate bugs for separate issues, this will greatly help triaging and tracking their resolution. To include useful information, use "ubuntu-bug firefox" to file the bugs.

I cannot observe the first issue. The tracking protection selector in the hamburger menu is always responsive when I open a first private window. Please provide detailed steps to reproduce the issue.

As for the second issue, I'm never getting a warning dialog box when closing a private window with more than one tab, despite the "browser.tabs.warnOnClose" setting being true (the default value). Not sure whether that's a bug or the expected behaviour.

[hbchoong (hbchoong)]

Thanks for taking the time to address this.

Noted and sorry - will ensure this is done in the future.

On the first issue, the computer needs to be started from a powered off state and subsequently firefox private browsing is opened for the very first time. This is how the issue is reproduced and the same is still being observed affecting the latest Firefox 62. Closing firefox and restarting the first private windows thereafter will not reproduce the issue.

With the second issue, yes I've noted these comments since 12.04 LTS or where this inconsistency continue to be prevalent. With mine it does provide the warning dialog box on default so I'm not able to add further unfortunately.

Again, your help looking into this is always much appreciated.

[Olivier Tilloy (osomon)]

I believe the first issue is not relevant anymore, as mozilla revamped the tracking protection feature in firefox 63 (which is now available in all supported series): https://blog.mozilla.org/blog/2018/10/23/latest-firefox-rolls-out-enhanced-tracking-protection/

I am therefore going to reword the bug description to include only the second issue. In the future please file separate bugs to track separate issues, this will ease a lot bug management. And do not confirm your own bugs, that should be done by someone else. Thanks!

[hbchoong (hbchoong)]

Understood, sorry.
May I ask what actually happens next in this process?

[Olivier Tilloy (osomon)]

Someone else should confirm your bug (I'll try to do that) and provide steps that make it 100% reproducible (if you can test on other machines and find out what setting trigger that warning dialog box that would be helpful).

Once confirmed, we should notify the upstream developers (mozilla) and investigate how to fix the issue. Firefox and Ubuntu are Free Software, so everyone is welcome to chime in and contribute to the resolution.

[Olivier Tilloy (osomon)]

I am unable to observe the issue.

I never get a warning when closing a private browsing window, even if it has several tabs open, and there doesn't seem to be any relevant option in about:config to control that.

I do get a warning when closing a normal window with several tabs open, but gnome shell never considers the window to become unresponsive. I have disabled screen blanking and locking and waited for 10 minutes, and the firefox window remains responsive and the warning dialog can be dismissed.

In your report you mention "after a while", how long would that be?
Are you seeing the problem with private browsing windows only, or also with normal windows?
Finally, with the latest update (63.0+build2-0ubuntu0.18.04.2), does the problem still exist?

[hbchoong (hbchoong)]

Very much appreciate your taking the time to follow up on this. After quite some struggles and hesitation I've gone ahead to re-install Firefox.

Having done so, I'm am now no longer able to observe or reproduce the issue reported.

In answer to your comments:

- I never get a warning when closing normal window with several tabs open, only when closing private windows with multiple tabs. (which appears to be the opposite of what you are seeing) Noted that this has been an on-going inconsistency in implementation requirements/intentions from Mozilla.

- 10 minutes is more than enough to have observed the issue.

I believe this issue should therefore now be closed here. If it does re-surface in the future, I will re-open it.
Thanks.

[Olivier Tilloy (osomon)]

Thanks for following up. I'm closing the report, feel free to re-open it in the future should the problem arise again.