410621 - [BC] borders touching edge of overflow area are cut when overflow isn't visible

Status: RESOLVED FIXED

(Core :: Layout: Tables, defect)

Description

[Hayo]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11

After constructing a scrolling table which is placed within a <div style="overflow:auto;...", the most left border of the td tags does not show up. The complete left border of the scrolling area is overdrawn by line of 1px (in background color).
The effect does not appear, if no DOCTYPE is given. The effect also does not appear for HTML 4.01, when no attribute for dtd is given. 
IE 6 and Opera 9 do not show this problem.

Reproducible: Always

Steps to Reproduce:
1. download html attachment
2 [review]. open attachment in Firefox
3. change DOCTYPE of html according to the included comments
4. Change border-left to 3px in order to see the overdrawing line on left border
Actual Results:  
There is no visible left border in the table.

Expected Results:  
There should be a 1 px line in color magenta on the left.

See sample code in attachment Left-TR-border-bug.html.

Comment 1

[Hayo]

Attachment: Sample html page code

Comment 2

[Daniel.S]

I'll add a reduced testcase shortly.

All right. An element which has its overflow property set to anything but 'visible' that contains a table which has border-collapse set to 'collapse' cuts parts of the top and left border (of the table) when these are touching the edge of the overflow area.

It is visible on branch and on trunk, but never in Quirks Mode.

It's only the left and top borders that may get cut, even in RTL mode.

Comment 3

[Daniel.S]

Attachment: reduced testcase

Comment 6

[Boris Zbarsky [:bzbarsky]]

Sounds like the table doesn't include its borders in its overflow area.  It probably should.

Comment 7

[Hayo]

Daniel's reduced test case also shows an additional horizontal scrollbar (on my linux system), that should not be there. Probably there is a problem with computing the width of the GUI's scrollbar that gives the table also an offset to the left. Part of the line seems to be hidden under the div.
The reduced test case also shows a strange behaviour, if you zoom in with Ctrl-Mousewheel. The most left line sometime gets thinner while everything else is getting larger.

Mozilla/5.0 (X11; U; Linux i686; de; rv:1.9.0.1) Gecko/2008070400 SUSE/3.0.1-1.1 Firefox/3.0.1
Running on SuSE 10.3/KDE 3.5

Comment 8

[Bernd]

thats the border area that triggers an overflow area outside of the table

Comment 9

[Daniel.S]

This has been fixed by Bug 155955.

Comment 10

[Boris Zbarsky [:bzbarsky]]

Can we add a reftest?

Comment 11

[Daniel.S]

Attachment: reftest

This is almost the same as the testcase. Fails in builds before Bug 155955 was fixed and passes after (trunk).

Comment 12

[Boris Zbarsky [:bzbarsky]]

Pushed test as http://hg.mozilla.org/mozilla-central/rev/3d0096fb2c41 and http://hg.mozilla.org/mozilla-central/rev/cf1bbf012e85

Thank you for doing that, Daniel!