1850661 - Export layout/reftests/radicalbar*.html to WPT

Status: RESOLVED WONTFIX

(Core :: MathML, task)

Description

[Frédéric Wang (:fredw)]

Extracted from bug 1847280.

I tried converting layout/reftests/radicalbar*.html to WPT, replacing
reftest-zoom with SpecialPowers.setFullZoom. However, that didn't work
because we cannot reset the zoom level after the screenshot and that
affects subsequent tests.

I also noticed that reftest-zoom=".2" is actually clamped to
zoom.minPercent so the radicalbar-*d.html are the same as
radicalbar-*c.html. That's not the case with
SpecialPowers.setFullZoom, and I realized that with the patch
bug 1011020 is actually still present for a 20% zoom level.
I also did verify that reverting the changes to
nsDisplayMathMLBar::Paint make radicalbar-*c.html fail. Maybe
it makes sense to restrict to values not less than zoom.minPercent
instead.

I also considered converting to a
testharness instead relying on SpecialPowers.snapshotWindowWithOptions
to check if the bar is visible. That would have made the test more
readable but the buffer returned does not seem to be affected by zoom level so that does not allow to reproduce bug 1011020.

See my attempts in attachment 9347517 [details] [diff] [review].

I guess the solution would be to support reftest-zoom in WPT tests or some version of the CSS zoom property.

Comment 1

[Frédéric Wang (:fredw)]

Attachment: WIP: Bug 1850661 - Export layout/reftests/radicalbar*.html to WPT. r=emilio

Comment 2

[Frédéric Wang (:fredw)]

Attached is a patch based on the CSS zoom property. Our current implementation does not seem to scale down the MathML radicals much (and does not allow to reproduce bug 1011020 when reverting the fix) so let's come back to this later.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

CSS zoom is not equivalent to browser zoom, so it's not an option unfortunately.

Comment 4

[Frédéric Wang (:fredw)]

Attachment: Bug 1850661 - Update comment regarding radicalbar*.html reftests. r=emilio

Comment 5

[Frédéric Wang (:fredw)]

OK, I uploaded a patch to update the comment. Let's land it and close as WONTFIX.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b54168d5d86c
Update comment regarding radicalbar*.html reftests. r=emilio

Comment 7

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/b54168d5d86c