327767 - CSS2 background-position:center; not handled properly

Status: RESOLVED INVALID

(Core :: Layout, defect)

Description

[johnboren]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1

Firefox is incorrectly parseing the background-position tag as meaning position with regard to the BOTTOM of the image. According to the W3C's CSS2 specifications, it should be aligned within the padding area (which, for large images, it is not), even though the padding was specifically set to include the entire viewport.

Reproducible: Always

Steps to Reproduce:
1.create a website foo.html
2.add a line in the body tag style="background-image:url("someimage.***"); background-postion:center;"
3.watch the image be incorrectly positioned

Actual Results:  
The image should, according to the W3C, be positioned first off within the padding area, and it just makes sense to align it with regard to the CENTER of the IMAGE. 

Expected Results:  
Probably the best example is to go over to someones computer who has IE and watch it render the same page correctly. 

For the actual CSS2 documentation, see http://www.w3.org/TR/REC-CSS2/colors.html

Comment 1

[crf]

"it just makes sense to align it with regard to the CENTER of
the IMAGE"

I don't know about that, I'm not familar enough with the document in question ...

---
From what I've seen of similar bugs, I think mozilla does things correctly.
You'll want to provide an example page, or a url where you see the problem, to be sure, because the report isn't very complete. And you may also want to read this bug, for it may be catching you --> 
https://bugzilla.mozilla.org/show_bug.cgi?id=243751#c6

background image is, unless otherwise specified, aligned with the body element (rather than the browser window). If the body element is small, it may appear that the background image is strangely positioned. I.E. does things differently, and against careful reading of the specification.

Opera is also a free download now: I sometimes find it interesting to compare renderings of a page between all three browsers.

Comment 2

[dolphinling]

Reporter, are you sure you're not seeing paragraph 4 of http://www.w3.org/TR/CSS21/colors.html#q2 ? If not, please provide a complete testcase or a page it occurs on; this report alone doesn't provide enough information.

Comment 3

[dolphinling]

-> INVALID. If you still believe this is being handled incorrectly, please reopen *and provide an example*.