[Affected versions]:
-64.0, 65.0b8, 66.0a1 (2019-01-07)

[Affected platforms]:

• Windows 10, Ubuntu 18.04, macOS 10.13;

[Steps to reproduce]:

1. Launch Firefox, enable content blocking - set it to Strict(so it prompts content blocking);
2. Open a new tab or access about:newtab
3. Access any webpage with trackers, ex: https://www.reddit.com/
4. Right click on the Go back one page button;
5. Hover over the New Tab entry;

[Expected result]:

• hover effect is properly displayed;

[Actual result]:

• as mouse is moved around the entry, it flickers;

[Regression range]:

• Not a regression since its also reproducible on the build where this was introduced, Nightly 2018-06-01;

[Additional notes]:

• attached recording with the issue;
• issue does not reproduce without the Content blocking pop-up menu;
• browser should not be maximized, so that the menus would overlap;
• the issue is not limited to the new tab entry alone, it affects all the other as well(if navigated on multiple websites before);

Updated summary, since the issues reproduces on both the menus.

This is a known issue when multiple popups are open.

Why don't we close the content blocking doorhanger?

That's not the identity popup, that's the UI tour for content blocking. Which is also why we don't close it, we don't want the user to be able to dismiss it as easily.

This seems like a pretty minor issue to me.

(In reply to :Gijs (he/him) from comment #2)

This is a known issue when multiple popups are open.

Do you have a bug for that so we can dupe to it?

(In reply to Matthew N. [:MattN] (PM me if requests are blocking you) from comment #4)

(In reply to :Gijs (he/him) from comment #2)

This is a known issue when multiple popups are open.

Do you have a bug for that so we can dupe to it?

I don't; we previously fixed this for some other context menus by moving the context menu in question into the relevant panel. That's clearly not really an option here. See bug 1378427 . I'm not sure if there's a platform bug on file for the issue or not. See also comments 3-5 in that bug. There's also https://bugzilla.mozilla.org/show_bug.cgi?id=492960#c20 .

OK, I'll move this to XUL widgets for triage then as we aren't going to fix this in the front-end.

This is caused by 1047530.

Bug 1047530 was resolved, so this should be fixed now?

The UI Tour for content blocking stuff has changed so I don't think we can verify that this is fixed, so resolving wfm.