Affected versions

• 69.0, 69.0b16, 70.0a1 (2019-08-25)

Affected platforms

• Windows 10, macOS 10.13, Ubuntu 18.04;

Steps to reproduce

1. Launch Firefox;
2. access and login with a valid account: https://outlook.live.com/mail/inbox
3. Click on the skype widtget to expand the chat pane;

Expected result

• Chat pane is displayed "properly";

Actual result

• padding (to right) is missing for the dropdown;
• the time is right on the edge of the dropdown, scroll bar overlaps it;

Regression range

• First bad: changeset: 9ed4cd3adbbb5eea2033abc78b583c6c12d3a28a build_date: 2018-09-26 04:21:16.514000
• Last good: build_date: 2018-09-26 01:54:15.718000 changeset: 5d624ee1b23d29116055ca149d24e8b95b086d91
• Pushlog: URL
• Potential regressor: 1492012

Additional notes

• attached screenshot with the issue;
• in the right side - after the add there is the layout with other browsers / unaffected builds;

Adding Xidorn in the loop for confirmation.

My first guess would be maybe webcompat addon incorrectly hide the scrollbar. The second guess is that the website does something wrong.

I don't have time to check until maybe this weekend, so if you can have a look at the style panel and see where the scrollbar-width use comes from, that would probably be very helpful. Otherwise I will check later. Keep ni? for now.

I might be wrong, but starting with the div bellow the conntent starts to get truncated so it might be around there?
Not sure if it helps with that much.
"swc-scroll-viewport swc-scroll-hide" data-test-id="swc-recentlist-scrollable" style="--ah-list:no-current; --ah-focus-deloser:inactive,snapshot-0;"

So, I think this is a problem of the website.

This happens when scrollbar-width is enabled (i.e. unrelated to scrollbar-color).

Basically, there is a rule .swc-scroll-viewport.swc-scroll-hide which sets margin-right: -17px to try hiding the scrollbar via counter its width, however, in another rule .swc-scroll-viewport it also sets scrollbar-width: none which hides the scrollbar. When scrollbar-width is enabled, the scrollbar is hidden via scrollbar-width, and the extra margin-right eats up the padding.

I don't think there is anything we can do from the engine side.

Mike, can we reach out to Microsoft on this?

Yep, I sent an email on our partner list.

I recommend we don't track this as a regression, since Microsoft should be able to fix this via a site update.

Still an issue on 80.0, 81.0a1 (2020-08-17).

I guess I should send a follow-up email.

Re-pinged our contacts on our partner list.

Reproduced on Firefox 78.11.0 esr on Win 10x64.

Currently clicking the Skype widget no longer opens a chat pane while in Outlook, it opens Skype in a new tab.
https://prnt.sc/irILZ47ZbXP0

Tested with:
Browser / Version: Firefox Nightly 103.0a1 (2022-06-22)
Operating System: Windows 10 Pro

Cristian are you getting the same behavior as you described in the report?

It appears that outlook.office365.com no longer supports Skype, but has Teams instead. This issue is no longer reproducible.