699987 - Fantom borders on fixed-positioned element adjoining to BODY element edges

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Marat Tanalin]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20100101 Firefox/8.0
Build ID: 20111102223350

Steps to reproduce:

See the testcase:
http://tanalin.com/_experimentz/bugs/fx/2011/fixed-element-fantom-border/

Needed conditions to reproduce the bug:
1. an element (DIV for example) has {position: fixed};
2. BODY (or HTML) element has url() as its background;
3. fixed-positioned element is _adjoining_ to BODY edges.

Fantom border displayed at that edges of element that (edges) are adjoining to BODY edges.


Actual results:

Fantom borders are displayed around fixed-positioned element.
Both firefox 8 (latest b6-RC version — Gecko/20100101 Firefox/8.0 ID:20111102223350) and Firefox 10a1 (latest nightly from today) are affected.

Firefox 7 has NO this bug.


Expected results:

Fixed-positioned element should not have fantom borders.

Comment 1

[Marat Tanalin]

Maybe related to (_not_ a dupe of) bug 685102.
Thanks.

Comment 2

[Marat Tanalin]

It seems the bug is specific to Windows 7 (and probably Vista).
Firefox 8 in Windows XP is not affected.

(Nevertheless, the bug is probably too serious regression to be included in final release of Firefox 8.)

Comment 3

[Mats Palmgren (inactive)]

Possible regression from bug 677095? (which landed 2011-08-12 for mozilla8)

Marat, please try a "mozilla-central" build dated before 2011-08-12 and one
a few days after and see if that's when the bug was introduced.  Thanks.
http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2011/08/

Comment 4

[Marat Tanalin]

(In reply to Mats Palmgren [:mats] from comment #3)

The bug was introduced in "2011-08-13-03-07-46-mozilla-central/firefox-8.0a1.en-US.win32" build (both 32-bit and 64-bit ones). Thanks.

Comment 5

[Marat Tanalin]

It seems the bug is fixed: it's not reproduceable anymore as of "2011-11-15-03-09-57-mozilla-central" build.

This is probably fixed by fixing bug 701528 (http://hg.mozilla.org/releases/mozilla-aurora/rev/77fd55b5d57d).

Comment 6

[Mats Palmgren (inactive)]

Marat, thanks for investigating the problem.