837189 - CSS3 background-size: cover not rendering as it should with background-attachment: fixed

Status: RESOLVED DUPLICATE of bug 836844

(Firefox :: Untriaged, defect)

Description

[toastal]

Attachment: background-fixed-cover-bug.PNG

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:21.0) Gecko/20130201 Firefox/21.0
Build ID: 20130201030927

Steps to reproduce:

I was working on styling a file locally. The next day (1/31/13) when Nightly updated, the styling of the background was no longer working as it had the day before.

My CSS rule that started failing:
html {
    background: url("../img/background.jpg") no-repeat fixed center;
    background-size: cover;
}

I found a demo site online that having the same issue: http://solemone.de/demos/fullsize-background-image-with-css3-background-size/

It wasn't working on Nightly on neither Windows 7 nor OSX 10.6.


Actual results:

The background image covers the browser window until you scroll. At that point, the background stops.


Expected results:

The background image should cover the browser window and stay fixed in the center as one scrolls.