1686268 - Left table border not consistently drawn i.e. drawn intermittently

Status: NEW

(Core :: Web Painting, defect, P3)

Description

[Schalk Neethling [:espressive]]

Attachment: Firefox 76.0a1

This was originally reported by :peterbe and then discussed in #firefox.

Check this out. It could be a Firefox Nightly bug only. Open https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Cheatsheet
and look at the main big table there. When you scroll down, it changes appearance. Do
you see it?

tl;dr The left border on the table is not consistently drawn. See screenshots.

I went as far back as Firefox 36 and could still see reproduce the problem on both Mac and Windows. One thing to note is that the left side border is conditionally drawn based on a media query so, I wonder whether this may be the source of the problem?

@media #{min-width: 63.9385em} {
  .standard-table {
	  border-left: 6px solid #276738;
  }
}

Comment 1

[Schalk Neethling [:espressive]]

Attachment: Firefox 70.0a1

Comment 2

[Schalk Neethling [:espressive]]

Attachment: Firefox 36 on Windows 8

Comment 3

[Timothy Nikkel (:tnikkel)]

Probably web painting or layout if it's been around that long.

Comment 4

[Timothy Nikkel (:tnikkel)]

It's hard to get a reduced testcase because when I save the page locally the resulting page using some js and it doesn't load properly.

Comment 5

[Timothy Nikkel (:tnikkel)]

Attachment: retestcase.html

This is fairly minimal.

Something with border-collapse probably.

Comment 6

[Timothy Nikkel (:tnikkel)]

There seems to be a bunch of border-collapse bugs, here are two that sounded similar bug 1527538 and bug 1072262.