Bug 209072

Summary:	[ Mac Debug ] http/tests/css/shared-stylesheet-mutation-preconstruct.html is flaky failing.
Product:	WebKit	Reporter:	Jason Lawrence <Lawrence.j>
Component:	CSS	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	webkit-bot-watchers-bugzilla, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Mac
OS:	macOS 10.14

Description Jason Lawrence 2020-03-13 11:53:31 PDT

http/tests/css/shared-stylesheet-mutation-preconstruct.html

Description:
This test is flaky failing on Mac Debug. It is flaky failing throughout the visible history shown in the link below.

History:
https://results.webkit.org/?suite=layout-tests&test=http%2Ftests%2Fcss%2Fshared-stylesheet-mutation-preconstruct.html&platform=mac&style=debug&flavor=wk2&flavor=wk1&limit=50000

Diff:
--- /Volumes/Data/slave/mojave-debug-tests-wk1/build/layout-test-results/http/tests/css/shared-stylesheet-mutation-preconstruct-expected.txt
+++ /Volumes/Data/slave/mojave-debug-tests-wk1/build/layout-test-results/http/tests/css/shared-stylesheet-mutation-preconstruct-actual.txt
@@ -175,7 +175,7 @@
 
 Test 12
 --------------------------------------
-PASS getComputedStyle(testElement, null).getPropertyValue('background-color') is 'rgb(0, 128, 0)'
+FAIL getComputedStyle(testElement, null).getPropertyValue('background-color') should be rgb(0, 128, 0). Was rgba(0, 0, 0, 0).
 
 @import url("data:text/css;charset=utf-8,%23testdiv%7Bbackground-color%3Agreen%20!important%7D");
 #testdiv { background-color: green; }

Comment 1 Radar WebKit Bug Importer 2020-03-13 11:54:06 PDT

<rdar://problem/60427174>

Comment 2 Jason Lawrence 2020-03-13 11:58:28 PDT

I have marked this test as failing while this issue is investigated.
https://trac.webkit.org/changeset/258417/webkit

Comment 3 Jason Lawrence 2020-03-13 12:57:53 PDT

I am able to reproduce this issue with r258414 using the command below.
run-webkit-tests --iterations 1000 --exit-after-n-failures 3 --force -f --debug http/tests/css/shared-stylesheet-mutation-preconstruct.html

[39/1000] http/tests/css/shared-stylesheet-mutation-preconstruct.html failed unexpectedly (text diff)
[65/1000] http/tests/css/shared-stylesheet-mutation-preconstruct.html failed unexpectedly (text diff)
[238/1000] http/tests/css/shared-stylesheet-mutation-preconstruct.html failed unexpectedly (text diff)
Exiting early after 3 failures. 235 tests run.

232 tests ran as expected, 3 didn't (765 didn't run):

Comment 4 Jason Lawrence 2020-03-23 15:51:54 PDT

*** Bug 209442 has been marked as a duplicate of this bug. ***