424283 - Firefox 3.0b5 renders the Acid1 test completely wrong when zoomed

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[spam_hole]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9b5pre) Gecko/2008032005 Minefield/3.0b5pre
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9b5pre) Gecko/2008032005 Minefield/3.0b5pre

Firefox 3.0b5 (as of today, March 20th) renders the Acid1 test completely wrong at a zoom level different from the default. This should not happen, considering that it would break the mere idea of having page zoom to have pages reflow wrong when zoomed.

Reproducible: Always

Steps to Reproduce:
1. Visit http://www.w3.org/Style/CSS/Test/CSS1/current/test5526c.htm (alias http://acid1.acidtests.org)
2. Zoom in or out any number of levels and observe that the test looks completely different.
Actual Results:  
The red "toggle" is on a line by itself, the bar maids and erbarme dich elements are floating past the edge of the black border container box, etc. In general, the box elements are mispositioned. See attachment.

Expected Results:  
Page is rendered like the reference rendering (http://www.w3.org/Style/CSS/Test/CSS1/current/sec5526c.gif), only smaller/bigger (this is what happens in Opera, Safari, and IE7)

Initially, I was going to report this as an outright failure, when I noticed the text thing. It is still wrong, in my opinion, since pages should not completely break when zoomed (yes, this is an Acid test, but that's not really an excuse).

Comment 1

[spam_hole]

Attachment: Screenshot of Acid1 test at -1 zoom level. Similar results are obtained by using other zoom levels, and/or setting the Zoom Text Only option.

Comment 2

[spam_hole]

Comment on attachment 310917 [details]
Screenshot of Acid1 test at -1 zoom level. Similar results are obtained by using other zoom levels, and/or setting the Zoom Text Only option.

Note that because the page is made much taller by this bug, I had to take the screenshot in full-screen mode.

Comment 3

[Jesse Ruderman]

I see the same thing on Mac.  Is this a rounding issue?

Comment 4

[spam_hole]

Yep, it looks like a rounding issue, since zooming it to various levels causes varying levels of brokenness.

Comment 5

[Jesse Ruderman]

My guess is that this is a dup of bug 417278.

Comment 6

[Jesse Ruderman]

Seems to have been fixed by the patch in bug 417178.