Bug 196985

Summary:

REGRESSION: (r244182) Layout Test editing/execCommand/insert-nested-lists.html is flaky

Product:

WebKit

Reporter:

Truitt Savell <tsavell>

Component:

Tools / Tests

Assignee:

Ryosuke Niwa <rniwa>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

ap, lforschler, rniwa, ryanhaddad, sabouhallawa, simon.fraser, sroberts, webkit-bug-importer, wenson_hsieh

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

See Also:

https://bugs.webkit.org/show_bug.cgi?id=197065

Attachments:

Description	Flags
Fixes the test	wenson_hsieh: review+

Truitt Savell

Reported 2019-04-16 14:25:51 PDT

The following layout test is flaky on Mac Release WK2 editing/execCommand/insert-nested-lists.html Probable cause: This test became flakey with https://trac.webkit.org/changeset/244182/webkit I reproduced this issue with command: run-webkit-tests editing/execCommand/insert-nested-lists.html --iterations 500 -f The test fails randomly on 244182 and passes fully on 244181. Flakiness Dashboard: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=editing%2FexecCommand%2Finsert-nested-lists.html Diff: --- /Volumes/Data/slave/mojave-release-tests-wk2/build/layout-test-results/editing/execCommand/insert-nested-lists-expected.txt +++ /Volumes/Data/slave/mojave-release-tests-wk2/build/layout-test-results/editing/execCommand/insert-nested-lists-actual.txt @@ -43,52 +43,39 @@ | | <ol> | <li> -| "bar" -| <ul> -| <li> -| <#selection-caret> +| <#selection-caret> After selecting a range and inserting another unordered list: | <ul> | <li> | "foo" | -| <ol> +| <ul> | <li> -| "bar" -| <ul> +| <#selection-caret> +| <ol> | <li> -| <#selection-caret> -| <ul> -| <li> After outdenting: | <ul> | <li> | "foo" | -| <ol> -| <li> -| "bar" -| <li> -| <#selection-caret> -| -| <ul> -| <ul> -| <li> +| <li> +| <#selection-caret> +| +| <ul> +| <ol> +| <li> After outdenting again: | <ul> | <li> | "foo" | -| <ol> -| <li> -| "bar" -| <li> -| "baz<#selection-caret>" -| -| <ol> -| <ul> -| <ul> -| <li> +| "baz<#selection-caret>" +| +| <ul> +| <ul> +| <ol> +| <li>

Attachments
Fixes the test (1.82 KB, patch) 2019-04-19 12:31 PDT, Ryosuke Niwa	wenson_hsieh: review+	Details Formatted Diff Diff
View All Add attachment proposed patch, testcase, etc.

Radar WebKit Bug Importer

Comment 1 2019-04-16 14:27:22 PDT

<rdar://problem/49954111>

Alexey Proskuryakov

Comment 2 2019-04-18 10:02:55 PDT

This is a bit surprising. This test doesn't use rAF, and generally looks like it should be deterministic. Said, Wenson, any ideas on how the regression could happen here?

Wenson Hsieh

Comment 3 2019-04-18 10:04:47 PDT

(In reply to Alexey Proskuryakov from comment #2) > This is a bit surprising. This test doesn't use rAF, and generally looks > like it should be deterministic. > > Said, Wenson, any ideas on how the regression could happen here? It actually does use requestAnimationFrame: await new Promise(resolve => requestAnimationFrame(resolve));

Shawn Roberts

Comment 4 2019-04-18 11:27:45 PDT

Found another editing test regressed by r244182. Linking to 197065

Ryosuke Niwa

Comment 5 2019-04-19 12:25:33 PDT

There is no reason to believe that waiting for rAF would cause UI process' runloop to run. So we need to be making an explicit round trip to UI process instead.

Ryosuke Niwa

Comment 6 2019-04-19 12:31:12 PDT

Created attachment 367811 [details] Fixes the test

Ryosuke Niwa

Comment 7 2019-04-19 12:33:25 PDT

Committed r244461: <https://trac.webkit.org/changeset/244461>

Ryosuke Niwa

Comment 8 2019-04-22 19:39:26 PDT

Looks like the flakiness is gone!

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