1691904 - Intermittent /css/css-text/hyphens/hyphens-shaping-002.html | Testing http://web-platform.test:8000/css/css-text/hyphens/hyphens-shaping-002.html != http://web-platform.test:8000/css/css-text/hyphens/reference/hyphens-shaping-002-ref.html

Status: RESOLVED DUPLICATE of bug 1392106

(Core :: Layout: Text and Fonts, defect, P5)

Description

Filed by: malexandru [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=329471706&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/FmlNTsnHR1egRh2hjlSzrw/runs/0/artifacts/public/logs/live_backing.log
Reftest URL: https://hg.mozilla.org/mozilla-central/raw-file/tip/layout/tools/reftest/reftest-analyzer.xhtml#logurl=https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/FmlNTsnHR1egRh2hjlSzrw/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

---

[task 2021-02-10T08:24:08.461Z] 08:24:08     INFO - TEST-PASS | /css/css-text/hyphens/hyphens-shaping-001.html | took 166ms
[task 2021-02-10T08:24:08.463Z] 08:24:08     INFO - TEST-START | /css/css-text/hyphens/hyphens-shaping-002.html
[task 2021-02-10T08:24:08.465Z] 08:24:08     INFO - PID 2336 | 1612945448463	Marionette	INFO	Testing http://web-platform.test:8000/css/css-text/hyphens/hyphens-shaping-002.html != http://web-platform.test:8000/css/css-text/hyphens/reference/hyphens-shaping-002-ref.html
[task 2021-02-10T08:24:08.609Z] 08:24:08     INFO - PID 2336 | 1612945448607	Marionette	INFO	No differences allowed
[task 2021-02-10T08:24:08.659Z] 08:24:08     INFO - TEST-UNEXPECTED-FAIL | /css/css-text/hyphens/hyphens-shaping-002.html | Testing http://web-platform.test:8000/css/css-text/hyphens/hyphens-shaping-002.html != http://web-platform.test:8000/css/css-text/hyphens/reference/hyphens-shaping-002-ref.html
[task 2021-02-10T08:24:08.659Z] 08:24:08     INFO - mismatch reftest has no differences
[task 2021-02-10T08:24:08.660Z] 08:24:08     INFO - REFTEST   IMAGE 1 (TEST):
[task 2021-02-10T08:24:08.660Z] 08:24:08     INFO - REFTEST   IMAGE 2 (REFERENCE):
[task 2021-02-10T08:24:08.660Z] 08:24:08     INFO - TEST-INFO took 176ms
[task 2021-02-10T08:24:08.660Z] 08:24:08     INFO - PID 4948 | 1612945448647	Marionette	INFO	No differences allowed
[task 2021-02-10T08:24:08.664Z] 08:24:08     INFO - TEST-FAIL | /css/css-text/line-breaking/line-breaking-021.html | took 218ms
[task 2021-02-10T08:24:08.665Z] 08:24:08     INFO - TEST-START | /css/css-text/line-breaking/line-breaking-atomic-001.html```

Comment 1

[Jonathan Kew [:jfkthame]]

Looks like this test is a bit fragile, because it loads a @font-face resource for the test content, but it's possible we'll capture the screenshot during the "block" period while the resource is still loading and the browser is using a fallback for layout, but rendering the text as invisible.

Using font-display: swap in the @font-face rule ought to help, by reducing the period during which the text may be invisible. A more thorough fix would be to use the CSS Font Loading API to ensure the font is loaded, but that may be overkill if this is already a rare intermittent issue.

Comment 2

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1691904 - Use font-display:swap to reduce the chance we'll capture a reftest screenshot while text is hidden because the font is still loading. r=#layout-reviewers

Comment 3

[Jonathan Kew [:jfkthame]]

Just an example of bug 1392106, really. There was supposed to be a hyphen glyph, and it didn't show up.

Comment 4

[Intermittent Failures Robot]

1 failures in 4322 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform and build breakdown:

• windows7-32: 1
  • opt: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1691904&startday=2021-02-08&endday=2021-02-14&tree=all