315076 - z-index for absolutely positioned element inside of element with {overflow: hidden} is ignored instead of applied

Status: RESOLVED FIXED

(Core :: Web Painting, defect)

Description

[Marat Tanalin]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8) Gecko/20051025 Firefox/1.5
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8) Gecko/20051025 Firefox/1.5

Absolutely positioned element nested into container that has {overflow: hidden} is shown BELOW next (after container) element that has {position: absolute} or {position: relative}. It takes place _independently_ of (positive) {z-index} value of first absolutely positioned element. Removal of {overflow: hidden} from container OR {position} from last ("next") element gets nested (positioned absolutely) element entirely visible.

Reproducible: Always

Steps to Reproduce:
1. make element with overflow: hidden;
2. make element nested into element created at step 1;
3. make element that has {position: absolute} (or {position: relative}) and follows after element created at step 1.

OR see the testcase
Actual Results:  
The element nested into container is BELOW the next-after-container element independently of (positive) {z-index} for nested element.

Expected Results:  
The element nested into container should be ABOVE the next-after-container element if nested element has positive z-index value (100 for example).

The problem takes place in both Forefox 1.07 and Firefox 1.5 RC 1 as well as in early branch builds of Firefox 1.5. Opera 8.5 (build 7700) and IE6 (6.0.2900.2180) renders the testcase CORRECTLY -- as expected results are.

Comment 1

[Martijn Wargers (dead)]

I seems to be fixed in my debug build that has the "frame display lists" patch in it (bug 317375).

Comment 2

[Steve England [:stevee]]

Testcase doesn't work with
Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a1) Gecko/20060124 Firefox/1.6a1 ID:2006012405
(black box next to grey box, different from IE)

Testcase does work with
Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a1) Gecko/20060126 Firefox/1.6a1 ID:2006012613
(black box above grey box, same as IE)

--> RESOLVED FIXED (by bug 317375)