1533044 - CSS border from thead renders unexpectedly when the table values change

Status: NEW

(Core :: Layout: Tables, defect, P3)

Description

[Gustav]

Attachment: mozilla_bug.html

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0

Steps to reproduce:

This rendering 'bug' only happens in Firefox with a specific <table> setup in the document.
(I have recreated one of the tables with minimal setup and attached it.)

1. Create a html document containing a table.
2. The table must contain a thead with colspan='x'
3. Add borderstyle to the thead with colspan.
4. Use Javascript to trigger a change on the first row in the tbody.

Actual results:

The border from the <thead> got rendered into <tbody> and can't be overridden with css. It also doesn't appear in the Page Inspector.

Expected results:

Borderstyle that is applied to the thead should not render into the tbody.

Comment 1

[Alice0775 White]

Last Good: 2007-10-14-05-trunk
First Bad: 2007-10-15-04-trunk

Regressed by: Bug 244135 - table borders disappear occasionally with border-collapse and rowspan

Comment 2

[Daniel Holbert [:dholbert]]

I can still reproduce this in Firefox Nightly 110.

Similar to bug 1710005 comment 3: after I follow the STR here and get unexpected borders, I can make them go away by zooming in & out.