620229 - "top" and "left" properties are wrongly computed for fixed positioning element

Status: RESOLVED WORKSFORME

(Core :: CSS Parsing and Computation, defect)

Description

[ithinc]

User-Agent:       Mozilla/5.0 (Windows NT 5.1; rv:2.0b9pre) Gecko/20101218 Firefox/4.0b9pre
Build Identifier: 

Open a Javascript shell, execute the following:

var ind = gBrowser.mTabContainer._tabDropIndicator;
ind.style.position = "fixed";
ind.style.top = "100px";
ind.style.left = "300px";

var style = getComputedStyle(ind);
alert([style.top, style.left]);


Reproducible: Always

Actual Results:  
The computed values are "0px" for "top" and "left".

Expected Results:  
The values should be "100px" and "300px".

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

This is probably about positioning not working in XUL.

Comment 2

[ithinc]

This works well in Firefox 3.6, so it is a regression in Firefox 4.0 betas.

Comment 3

[Ed Morley [:emorley]]

Would you be able to try and find the regression range:
https://wiki.mozilla.org/QA/Triage#How_to_Help_with_Regressions_--_Finding_Regression_Windows

Thanks!

Comment 4

[ithinc]

It happened between nightly 20100309 and 20100310, but I find that the tab drop indicator changed from xul:hbox to xul:image between the two versions.

Comment 5

[Ed Morley [:emorley]]

Thanks for the regression range. Pushlog using revs rather than dates:

http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=dcfcfca09b45&tochange=fd26cf0fd809

In that range is bug 508499 which is presumably the change you mention in comment 4.

Comment 6

[ithinc]

I have tested another xul:image introduced by xbl binding.

[code]
var searchbar = document.getElementById('searchbar');
var ind = document.getAnonymousElementByAttribute(searchbar, "anonid", "search-go-button");
ind.style.position = "fixed";
ind.style.top = "100px";
ind.style.left = "300px";

var style = getComputedStyle(ind, null);
alert([style.top, style.left]);
[/code]

It seems the problem has been existing in Firefox 3.6, so probably not introduced by bug 508499. Sorry for the misleading.

Comment 7

[ithinc]

xul:hbox introduced by xbl binding works well with fixed positioning though.

Comment 8

[BugBot [:suhaib / :marco/ :calixte]]

In the process of migrating remaining bugs to the new severity system, the severity for this bug cannot be automatically determined. Please retriage this bug using the new severity system.

Comment 9

[Daniel Holbert [:dholbert]]

Sounds like this may have been XUL/XBL related, but XUL/XBL have been removed and aren't supported anymore.

In any case: I think this is worksforme. I tried the STR from comment 0 but at example.org with web console and with var ind = $0 after inspecting the div element, and I got the expected results (100px and 300px).