1400083 - @font-face leading to inconsistent height calculation

Status: UNCONFIRMED

(Core :: Layout, defect, P3)

Description

[Florian Rivoal]

Attachment: table-cell-001.html

I've found, while writing test cases for web-platform-tests, two cases of non deterministic layout, when reloading the page (or doing so with the dev tools open vs closed) randomly yields different results.

1) table-cell-001.html (you need the Ahem font to be to be installed for this test to work)

Reloading the page will change the logical height of the second table cell randomly between 0 and the height needed to fit the content.

Note that removinv the

2) line-height-007.html

Reloading the page, or doing so with vs without the dev tools open, will randomly change the line height calculations. See also comments in the source, for seemingly unrelated things that appear to have an effect.

Comment 1

[Florian Rivoal]

Attachment: line-height-007.html

Comment 2

[Florian Rivoal]

Note: reference to other tests in the comments of line-height-007.html refer to tests in this directory: https://github.com/frivoal/web-platform-tests/tree/line-height-experiments/css/css-line-height

Comment 3

[Florian Rivoal]

dbaron made some comments about table-cell-001 in https://github.com/w3c/web-platform-tests/pull/6969#pullrequestreview-62556277

Comment 4

[Emilio Cobos Álvarez [:emilio]]

(In reply to Florian Rivoal from comment #0)
> Reloading the page will change the logical height of the second table cell
> randomly between 0 and the height needed to fit the content.
> 
> Note that removinv the

Missing text here?

Anyway, there's definitely a bug here, thanks a lot for reporting it!

The reason why the @font-face rule may be needed is because finishing loading it may reflow the document, maybe covering the issue?

There's at least another buggy table behavior I'm aware of, which is bug 1388898, though I doubt this one is the same issue... dbaron may of course have more background or ideas about this particular case.

Comment 5

[Florian Rivoal]

> > Note that removinv the

> Missing text here?

Ooos, sorry.

Note that removing the @font-face will stop the non-determinism, even though I can't figure out why it would make any difference.