793222 - Odd & Even Width -linear-gradient Firefox Bug

Status: UNCONFIRMED

(Core :: Layout, defect)

Description

[p.h.howells]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:17.0) Gecko/17.0 Firefox/17.0
Build ID: 20120921042009

Steps to reproduce:

Gave Div elements striped background images using -linear-gradient CSS.

I have tested this in Firefox 15 and Aurora 17.0a2 on OS X 10.6.8.  


Actual results:

The stripes had correct expected widths when rendered in a div with an even numbered pixel width.

But the stripes had incorrect widths when rendered in a div with an odd numbered pixel width.


Expected results:

The stripes should have been rendered at their correct expected widths regardless of the width of the Div element they were rendered in.

Comment 1

[p.h.howells]

Attachment: example of odd even width linear gradient bug

Comment 2

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

Attachment: screen shot on Linux

This is what I'm seeing on Linux, which seems like the correct rendering, given that I'd expect to see a 1px horizontal shift because the background-position is horizontally centered (and therefore centering within 501px yields 250.5px which rounds up to 251px.

Is this Mac-only?

Comment 3

[p.h.howells]

Attachment: comparison renders with other browsers on OSX

I agree that the Linux screenshot shows correct expected rendering.  Perhaps this is indeed a Firefox on Mac OSX issue?

The attached .png file shows the correct behaviour also being exhibited by Opera, Safari and Chrome (all on OSX, and when the css is tweaked to use their vendor prefixes) in comparison with Firefox.