458789 - Drop-down appears in the wrong place for a menulist above a wrapping description

Status: NEW

(Core :: XUL, defect)

Description

[Igor Tandetnik]

User-Agent:       Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; GoogleT5; .NET CLR 1.1.4322; InfoPath.1; .NET CLR 2.0.50727)
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.3) Gecko/2008092417 Firefox/3.0.3

If a XUL document has a wrapping <description> at the bottom, and a menulist above it, the drop-down menu is not properly attached to this menulist.

Reproducible: Always

Steps to Reproduce:
Load sample XUL file (attached)
Actual Results:  
There's a gap between the menulist and its drop-down (see attached screenshot)

Expected Results:  
The drop-down should be right underneath the menulist.

Comment 1

[Igor Tandetnik]

Attachment: Repro example

Comment 2

[Igor Tandetnik]

Attachment: Screenshot of the problem

Comment 3

[Ria Klaassen (not reading all bugmail)]

This regressed on 4 July 2007 so it is probably a regression from Bug 279703.

Comment 4

[Igor Tandetnik]

It's even worse with the latest FireFox. Not only is there still a gap between the menulist and the drop-down, but there's a gap between where the mouse pointer is, and the item that gets highlighted. I don't know how to capture this in a screenshot, but if you try the live repro, you would need to move the mouse about an inch above the drop-down in order to highlight the items way below. Clicking the mouse at this point just closes the drop-down without selecting the highlighted item (I guess because the click is actually outside the drop-down).

Comment 5

[Timothy Nikkel (:tnikkel)]

There is a decent chance this got fixed by bug 1130400 is anyone wants to test.

Comment 6

[Emil Pasca [:emilpasca]]

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0

I have tested this issue on the latest Firefox release (46.0.1, Build ID: 20160502172042),latest Nightly(49.0a1, Build ID: 20160518030234) and on the latest Developer Edition (48.0a2, Build ID: 20160518004015) with e10s disabled. I've opened the attachment 341962 [details] and I could not reproduce it. I've clicked on the menulist and the dropdown appeared underneath it. 
However, I was able to reproduce it on Nightly and Aurora with e10s enabled, here, when I clicked on the menulist, the dropdown didn't appeared anywhere.
In order to test this bug I have used the Remote XUL Manager 1.3.1 add-on.