1332668 - Header border style in table intermittently copied to table rows

Status: NEW

(Core :: Layout: Tables, defect)

Description

[martinjamesgraham]

Attachment: dodgyBorder.png

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36

Steps to reproduce:

Made a table with the header cells (th) having a set border style - see http://jsfiddle.net/ukxs1aqb/10/

Wiggling the rendered table up and down with the mouse (not the scroll bar) often results in table cells being rendered with the header border - dom inspection shows they aren't actually picking up the style itself, so it must be a rendering bug. Sometimes leaving it alone for a minute means it produces the erroneous borders by itself too.

This is a smaller test case in which it happens intermittently, but it happens without fail on a more complicated table I have (larger and more css rules). The transition rule doesn't seem to affect it on my larger case, but it happens more regularly in the jsfiddle if I included it - maybe indicates a timing issue?


Actual results:

See the attached image (dodgyBorder.png)


Expected results:

The table cells in the table body should have no border, just the cells in the table header row

Comment 1

[martinjamesgraham]

I can also get the effect by wiggling the scroll bar up and down (not just the mouse as I said in the original post)

Comment 2

[martinjamesgraham]

Is very similar to this bug from 9 years ago --> https://bugzilla.mozilla.org/show_bug.cgi?id=902835 difference being my border appears and theirs disappears (and their bug is still there, the test case still shows the failing on firefox 50)

Comment 3

[martinjamesgraham]

9 years, I meant 4. Why don't these comments have an edit facility, at least until someone replies!? Sorry. But anyways, the bug is very similar.

Comment 4

[martinjamesgraham]

Workaround: Place span elements within the th elements, and apply the border to the spans rather than the th's and the problem doesn't occur.

http://jsfiddle.net/ukxs1aqb/16/