1109036 - Website menus at get-loans.co.za no longer working correctly in Firefox 34 & later (when "opacity: 0.94" is present)

Status: NEW

(Core :: Layout, defect)

Description

[simplafied]

Attachment: getloans.png

User Agent: Mozilla/5.0 (Windows NT 6.2; rv:34.0) Gecko/20100101 Firefox/34.0
Build ID: 20141126041045

Steps to reproduce:

I am a webmaster of http://www.get-loans.co.za/ the site's menu is a drop down that now no longer displays correctly since I updated to Firefox 34.0.5. Was working in all prior releases and still works fine in IE / Chrome.

Not sure of the how to fix it now everything was okay, though will try... a bit confusing. If there is a fix please let me know ASAP. 
Nicholas
[e-mail]


Actual results:

The menu is hidden under the content.


Expected results:

The menu of http://www.get-loans.co.za/ should appear above the content.

Comment 1

[simplafied]

Okay, I have just removed opacity from the menu and it is now working again in FF 34.0.5 though this does remain a bug related to Opacity / Z-Index.

Comment 2

[:Gijs (he/him)]

What was the opacity set on? Can you provide a simpler testcase? I can't reproduce the issue from the screenshot setting opacity to e.g. 0.5 on the .menutop or #menuwrapper elements.

Comment 3

[simplafied]

(In reply to Gijs Kruitbosch from comment #2)
> What was the opacity set on? Can you provide a simpler testcase? I can't
> reproduce the issue from the screenshot setting opacity to e.g. 0.5 on the
> .menutop or #menuwrapper elements.

Hi, I have setup the old opacity as it was with the error at the URL below
http://get-loans.co.za/test/index2.html

The issue is in this part of the CSS and when the opacity is removed it works.

#p7menubar li {
	float: left;
	width: 10em;
	opacity: 0.94;
	filter: alpha(opacity=94); /* For IE8 and earlier */
}

Comment 4

[Daniel Holbert [:dholbert]]

(In reply to simplafied from comment #3)
> Hi, I have setup the old opacity as it was with the error at the URL below
> http://get-loans.co.za/test/index2.html

Thanks for posting that version. I can reproduce the behavior change you describe there, in current nightly builds for Linux -- menu contents not showing up, when hovering the menu items at the top of the page.

Regression range on mozilla-central:
{
Last good revision: 0894d2cdb16d (2014-07-20)
First bad revision: 5b64c42742cd (2014-07-21)
Pushlog:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0894d2cdb16d&tochange=5b64c42742cd
}

Looks like a regression from bug 1022612. Marking as a regression from that bug. (It's already got some dependent bugs that mention opacity -- e.g. bug 1111439 or bug 1115237. This is probably the same underlying issue as those bugs; we can mark as a duplicate as-appropriate, when we've got more info or when one of the bugs is fixed.).

Comment 5

[Daniel Holbert [:dholbert]]

Good news; if this is the same underlying issue as bug 1111439, then it sounds like there's already a patch written that fixes it (per bug 1111439 comment 8).  (The patch itself is in bug 1111753.)