1819455 - transform-input-013.html is failing just because it's fuzzy

Status: RESOLVED FIXED

(Core :: Web Painting, task)

Description

[Daniel Holbert [:dholbert]]

interop2023-relevant WPT transform-input-013.html is shown as failing on wpt.fyi, but it seems to just be a fuzzy failure, from slightly different antialiasing between testcase and reference case.

(Interestingly, it's not failing for us on our own TreeHerder CI -- we don't have any .ini file to note any failure or additional-fuzziness-needed. I wonder if the wpt.fyi test infrastructure is substantially different from ours for some reason?)

wpt.fyi: https://wpt.fyi/results/css/css-transforms/transform-input-013.html

"show details" indicates:

Found 2506 pixels different, maximum difference per channel 129

The test has

    <meta name="fuzzy" content="maxDifference=0-128;totalPixels=0-2254">

So we are overshooting maxDifference by 1 and totalPixels by 252.

We should just update the fuzzy metrics; this is a marginal increase and the failure is clearly a fuzzy-failure.

(Note, bug 1733673 seems to be where the current fuzz factor was added. It's possible that it was sufficient to allow us to pass at the time, but then something changed about the test environment -- e.g. fonts, resolution, OS version -- such that our fuzzy metrics changed a bit.)

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: Bug 1819455: Loosen fuzzy threshold on WPT test transform-input-013.html to match observed values on wpt.fyi harness. r?#layout-reviewers

This test compares transformed input elements against untransformed ones. This
can end up producing slight subpixel positioning differences at paint time,
which results in a fuzzy reftest failure. The test already has a fairly
liberal fuzzy allowance, and this patch just relaxes that a bit more to account
for the fuzzy differences that we're currently seeing on the wpt.fyi harness.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/575b23bd8069
Loosen fuzzy threshold on WPT test transform-input-013.html to match observed values on wpt.fyi harness. r=layout-reviewers,emilio

Comment 3

[Web Platform Test Sync Bot (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/38797 for changes under testing/web-platform/tests

Comment 4

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/575b23bd8069

Comment 5

[Web Platform Test Sync Bot (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot