Bug 224910

Summary:

REGRESSION (r276377): [ iOS, EWS ] scrollingcoordinator/ios/fixed-inside-sticky-no-stacking-context-2.html is a constant Image Failure

Product:

WebKit

Reporter:

Robert Jenner <jenner>

Component:

Scrolling

Assignee:

Tim Nguyen (:ntim) <ntim>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

don.olmstead, koivisto, mrobinson, ntim, simon.fraser, webkit-bot-watchers-bugzilla, webkit-bug-importer

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
Expected, Actual, and Diff images for failing test.	none
Patch	none
Patch	none

Robert Jenner

Reported 2021-04-21 19:15:40 PDT

scrollingcoordinator/ios/fixed-inside-sticky-no-stacking-context-2.html is a constant Image failure on iOS, and is slowing down EWS queues. WEBKIT RESULTS HISTORY: https://results.webkit.org/?suite=layout-tests&test=scrollingcoordinator%2Fios%2Ffixed-inside-sticky-no-stacking-context-2.html EWS FAILURE: https://ews-build.s3-us-west-2.amazonaws.com/iOS-14-Simulator-WK2-Tests-EWS/r426730-11881/results.html IMAGE DIFF LINK: https://build.webkit.org/results/Apple-iOS-14-Simulator-Release-WK2-Tests/r276393%20(1090)/scrollingcoordinator/ios/fixed-inside-sticky-no-stacking-context-2-diffs.html Diff images are also attached to this bug below.

Attachments
Expected, Actual, and Diff images for failing test. (5.54 KB, application/zip) 2021-04-21 19:16 PDT, Robert Jenner	no flags	Details
Patch (2.44 KB, patch) 2021-04-28 00:04 PDT, Tim Nguyen (:ntim)	no flags	Details Formatted Diff Diff
Patch (3.28 KB, patch) 2021-04-28 05:47 PDT, Tim Nguyen (:ntim)	no flags	Details Formatted Diff Diff
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.

Robert Jenner

Comment 1 2021-04-21 19:16:53 PDT

Created attachment 426764 [details] Expected, Actual, and Diff images for failing test. Attaching images to this bug.

Robert Jenner

Comment 2 2021-04-21 19:28:23 PDT

Updated test expectations to Failure here to speed up EWS: https://trac.webkit.org/changeset/276416/webkit

Robert Jenner

Comment 3 2021-04-21 19:46:06 PDT

Was able to reproduce the failure on iOS14 Simulator Release ToT using the following test: run-webkit-tests --ios-simulator scrollingcoordinator/ios/fixed-inside-sticky-no-stacking-context-2.html -f There are a lot of revisions that did not get built, so I'm not able to verify a regression point. However, it appears that changes to Scroll Snap at r276382 is the likely cause of the test's failure: https://trac.webkit.org/changeset/276382/webkit

Radar WebKit Bug Importer

Comment 4 2021-04-21 19:51:23 PDT

<rdar://problem/76995693>

Martin Robinson

Comment 5 2021-04-22 08:49:45 PDT

I took a look at this and I think the culprit here might be r276377. The test starts passing after reverting that commit, but not after reverting r276382.

Ryan Haddad

Comment 6 2021-04-22 14:13:42 PDT

(In reply to Martin Robinson from comment #5) > I took a look at this and I think the culprit here might be r276377. The > test starts passing after reverting that commit, but not after reverting > r276382. Thanks for looking! I see the test uses "will-change: transform", so that is likely.

Tim Nguyen (:ntim)

Comment 7 2021-04-28 00:04:47 PDT

Created attachment 427242 [details] Patch

Tim Nguyen (:ntim)

Comment 8 2021-04-28 05:47:02 PDT

Created attachment 427254 [details] Patch

EWS

Comment 9 2021-04-28 08:45:07 PDT

Committed r276716 (237120@main): <https://commits.webkit.org/237120@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 427254 [details].

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