Bug 195341

Summary:	[ iOS Simulator ] REGRESSION (r237087) Layout Test fast/viewport/ios/*-width-viewport-after-changing-view-scale.html is a flaky failure
Product:	WebKit	Reporter:	Shawn Roberts <sroberts>
Component:	Tools / Tests	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	lforschler, ryanhaddad, thorton, webkit-bot-watchers-bugzilla, webkit-bug-importer, wenson_hsieh
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified

Description Shawn Roberts 2019-03-05 14:45:47 PST

The following layout tests are flaky on iOS Simulator

fast/viewport/ios/constant-width-viewport-after-changing-view-scale.html
fast/viewport/ios/device-width-viewport-after-changing-view-scale.html

Probable cause:

Test has been a flaky failure since it was created in r237087

Around revision 240714 I had to add --child-processes 4 to get it to fail, but it produced the same diffs

Reproduced with :

run-webkit-tests fast/viewport/ios/constant-width-viewport-after-changing-view-scale.html fast/viewport/ios/device-width-viewport-after-changing-view-scale.html --iterations 50 -f --ios-simulator --child-processes 4

Flakiness Dashboard:

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=%20fast%2Fviewport%2Fios%2Fconstant-width-viewport-after-changing-view-scale.html%20fast%2Fviewport%2Fios%2Fdevice-width-viewport-after-changing-view-scale.html

Diffs

--- /Volumes/Data/slave/ios-simulator-12-release-tests-wk2/build/layout-test-results/fast/viewport/ios/constant-width-viewport-after-changing-view-scale-expected.txt
+++ /Volumes/Data/slave/ios-simulator-12-release-tests-wk2/build/layout-test-results/fast/viewport/ios/constant-width-viewport-after-changing-view-scale-actual.txt
@@ -1,7 +1,7 @@
 setViewScale(0.50)
-window size: [1280, 2192]
+window size: [640, 1096]
 square size: [128, 219]
-zoom scale: 0.25
+zoom scale: 0.50
 
 setViewScale(0.75)
 window size: [853, 1461]

--- /Volumes/Data/slave/ios-simulator-12-release-tests-wk2/build/layout-test-results/fast/viewport/ios/device-width-viewport-after-changing-view-scale-expected.txt
+++ /Volumes/Data/slave/ios-simulator-12-release-tests-wk2/build/layout-test-results/fast/viewport/ios/device-width-viewport-after-changing-view-scale-actual.txt
@@ -29,9 +29,9 @@
 zoom scale: 1.25
 
 setViewScale(1.00)
-window size: [320, 548]
+window size: [256, 438]
 square size: [32, 55]
-zoom scale: 1.00
+zoom scale: 1.25
 
 setViewScale(0.75)
 window size: [427, 731]

Comment 1 Radar WebKit Bug Importer 2019-03-05 15:00:50 PST

<rdar://problem/48616298>

Comment 2 Ryan Haddad 2019-03-06 15:46:53 PST

fast/viewport/ios/device-width-viewport-after-changing-view-scale.html  is causing false positives on EWS, so we should do something about this soon.

Comment 3 Wenson Hsieh 2019-03-06 15:48:12 PST

(In reply to Ryan Haddad from comment #2)
> fast/viewport/ios/device-width-viewport-after-changing-view-scale.html  is
> causing false positives on EWS, so we should do something about this soon.

Understood — I'll prioritize these tests.

Comment 4 Ryan Haddad 2019-03-08 16:54:14 PST

(In reply to Ryan Haddad from comment #2)
> fast/viewport/ios/device-width-viewport-after-changing-view-scale.html  is
> causing false positives on EWS, so we should do something about this soon.
Marked test as flaky to help out EWS in http://trac.webkit.org/projects/webkit/changeset/242665

Comment 5 Shawn Roberts 2019-04-02 08:58:25 PDT

Marked fast/viewport/ios/constant-width-viewport-after-changing-view-scale.html flaky in https://trac.webkit.org/changeset/243743/webkit while waiting for a fix.