Bug 307607 – REGRESSION(305691@main): [Tahoe] TestWebKitAPI.UnifiedPDF.SnapshotsPaintPageContent is flaky failure

• Status: RESOLVED
• Resolution: FIXED
• Component: New Bugs

[Marta Darbinyan]

The following test is flaky test on Tahoe configuration within the range of change 305692@main This is flaky on EWS bots and false-positive across different PRs.

TestWebKitAPI.UnifiedPDF.SnapshotsPaintPageContent


02:15:26.240 30896     TestWebKitAPI.UnifiedPDF.SnapshotsPaintPageContent
02:15:26.240 30896         2026-02-10 01:47:42.739 TestWebKitAPI[46433:16983303] NSEventConcurrentProcessingEnabled=NO
02:15:26.240 30896         CoreGraphics PDF has logged an error. Set environment variable "CG_PDF_VERBOSE" to learn more.
02:15:26.240 30896         
02:15:26.240 30896         /Volumes/Data/worker/macOS-Tahoe-Debug-Build-EWS/build/Tools/TestWebKitAPI/Tests/WebKitCocoa/UnifiedPDFTests.mm:663
02:15:26.240 30896         Value of: foundNonWhitePixel
02:15:26.240 30896           Actual: false
02:15:26.240 30896         Expected: true


Tets result:
https://ews-build.webkit.org/#/builders/165/builds/10055

Test history:
https://results.webkit.org/?suite=api-tests&test=TestWebKitAPI.UnifiedPDF.SnapshotsPaintPageContent&version_name=Tahoe

[Radar WebKit Bug Importer]

<rdar://problem/170186477>

[Marta Darbinyan]

Pull request: https://github.com/WebKit/WebKit/pull/58809

[EWS]

Test gardening commit 307674@main (66d6a97b9521): <https://commits.webkit.org/307674@main>

Reviewed commits have been landed. Closing PR #58809 and removing active labels.

[Abrar Rahman Protyasha]

Okay, this is a test problem, and it got exposed starting 305691@main.

The test asserted that a web view snapshot contained non-white pixels, but this assertion would also be successful if no content showed up (and the underlying page background layer was gray, i.e. pre-305691@main behavior).

Now, when we see the same issue where no content shows up, since the underlying page background layer is white, we fail the assertion.

We should have been flakily failing this assertion in the past, too, it’s just that our non-white page background layer produced misleading results.

[Abrar Rahman Protyasha]

Pull request: https://github.com/WebKit/WebKit/pull/58881

[EWS]

Committed 307748@main (3b69954dcfea): <https://commits.webkit.org/307748@main>

Reviewed commits have been landed. Closing PR #58881 and removing active labels.