Note

• Have valid Office365 credentials

Found in

• Firefox 106.0b2

Affected versions

• Firefox 106.0b2
• Nightly 107.0a1
• Firefox 105.0

Affected platforms

• macOS 13 Ventura
• Windows 10

Steps to reproduce

1. Open a Powerpoint presentation in https://office.live.com/start/PowerPoint.aspx?omkt=en-US&auth=1&nf=1

2. Click on a slide where the title and subtitle were added

3. Select some text from the slide and open the context menu by right-clicking

4. Select Cut or Copy options from the context menu

Expected result

• The selected text should be cut or copied according to the option used from the context menu.

Actual result

• The options Cut/Copy from the context menu are not functional, although they can be selected by clicking, and the page freezes immediately after their selection.

The message "This page is slowing down Firefox. To speed up your browser, stop this page." is displayed at the top of the page and the Powerpoint page is functional again only after refresh.

Regression range

Not a recent regression because this can be reproduced in Nightly 86.0a1 as well.

:epopescu, if you think that's a regression, could you try to find a regression range using for example mozregression?

Hi Ina Popescu,
A performance profile would also be appreciated here!

I can reproduce the browser hang, so I captured the log from the other browser window.
Profiler Log : https://share.firefox.dev/3Sei88j

Please find attached the performance profile from my side. Thanks

From both profiles, content process is busy on executing scripts. I could even reproduce this on 90, so this doesn't look like a regression from our side, maybe Powerpoint has changed something recently and has some issue on Firefox? Ksenia, do you aware there is any existing webcompat issues about this? Thanks!

Ksenia, do you aware there is any existing webcompat issues about this? Thanks!

I didn't come across any similar reports recently. But there seems to be an infinite do/while loop caused by this function:

      if (a.Jlc) {
        do b = new $ha(a.RIa, a.Dj),
        a.Ua.Ha('ORSC', b, null),
        a.Jlc = a.wmc(a, a.EZ),
        b = Wha(a);
        while (a.Jlc && !le(a) && !b);
        a.Jlc ? b || (b = new cia(a.RIa, a.Dj), a.Ua.Ha('OY', b, null), a.Jma()) : Xha(a) || (b = new bia(a.RIa, a.Dj), a.Ua.Ha('OC', b, null), ne(a))
      } else b = new bia(a.RIa, a.Dj),

not sure why this condition a.Jlc && !le(a) && !b doesn't evaluate to false just yet. I'll try to debug it more tomorrow and send an email to our mailing list with Microsoft to see if they can take a look.

Just an update here, I've sent an email to the mailing list with Microsoft and got a response that it'll be routed to the proper team.

The issue is still reproducible.

Tested with:

Browser / Version: Firefox Nightly 111.0a1 (2023-01-18) (64-bit)
Operating System: Windows 10 PRO x64

Notes:

1. Reproducible regardless of the status of ETP.
2. Reproducible on the latest build of Firefox Nightly and Release.
3. Works as expected using Chrome.
4. Performance profile attached: https://share.firefox.dev/3XEdDWV