Bug 198085 – REGRESSION (r244848-244849) [iOS] Several sizing , css and rendering tests are flakily failing in tandem on testers

• Component: Tools / Tests
• Status: RESOLVED DUPLICATE

[Shawn Roberts]

Created attachment 370344 [details]
Test List

The following issue is occurring only on iOS Simulator Release and Debug

Close to 100 tests can fail when run in a particular order. Most tests are css, sizing and rendering tests.

My notes will address the test case I am using to reproduce the failures

Probable cause:

After changes in either:

https://trac.webkit.org/changeset/244848/webkit
or
https://trac.webkit.org/changeset/244849/webkit

When you run the following test list on either iOS Simulator Release or Debug, 44 tests will fail at sizing differences, or image diffs there are what appears to be squares being drawn. The tests will fail/image only failure, then pass on retry.

Reproduced with:

run-webkit-tests --test-list=/tf --child-process 1 --ios-simulator

Link to an example run of this happening to see results.

https://build.webkit.org/results/Apple%20iOS%2012%20Simulator%20Debug%20WK2%20(Tests)/r245469%20(3751)/results.html

The reproduction I linked with the test list will cause all 44 of those tests to fail when they are run after: 
fast/viewport/ios/minimum-scale-after-changing-view-scale.html
ietestcenter/css3/bordersbackgrounds/border-radius-sum-of-radii-002.htm

All of the ietestcenter tests will fail, and create an expected image result for themselves. Then subsequent runs fail, and pass on retry. 

Test case failed in spade of r244850, passed in r244840. There are no revisions to test with in between. 

Flakiness Dashboard:

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fborder-radius-with-three-values-001.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fborder-radius-with-two-values-001.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fborder-top-left-radius-values-001.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fborder-top-left-radius-values-002.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fborder-top-left-radius-values-003.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fborder-top-left-radius-values-004.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fborder-top-right-radius-values-004.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fbox-shadow-001.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fbox-shadow-002.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fbox-shadow-003.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fbox-shadow-004.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fcolor-behind-images.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Fnone-as-image-layer.htm%20ietestcenter%2Fcss3%2Fbordersbackgrounds%2Forder-of-images.htm%20imported%2Fblink%2Fcompositing%2Fwill-change%2Fstacking-context-creation.html%20imported%2Fblink%2Ffast%2Fclip%2Fnested-rounded-rect.html%20imported%2Fblink%2Ffast%2Fmulticol%2Fvertical-lr%2Ffloat-break.html%20imported%2Fblink%2Ffast%2Fmulticol%2Fvertical-lr%2Ffloat-content-break.html%20imported%2Fblink%2Ffast%2Fmulticol%2Fvertical-lr%2Ffloat-edge.html%20imported%2Fblink%2Fsvg%2Fdom%2Fviewspec-aspectparams.html%20imported%2Fblink%2Fsvg%2Fdom%2Fviewspec-transformparams.html%20imported%2Fblink%2Fsvg%2Fdom%2Fviewspec-viewboxparams.html%20imported%2Fblink%2Fsvg%2Fdom%2Fviewspec-viewtargetparams.html%20imported%2Fblink%2Fsvg%2Fdom%2Fviewspec-zoomandpanparams.html%20imported%2Fblink%2Ftransforms%2Finline-transform-and-clipping-roots.html%20imported%2Fmozilla%2Fsvg%2Fsizing%2Finline--display-block--01.xhtml%20imported%2Fmozilla%2Fsvg%2Fsizing%2Finline--display-inline--01.xhtml%20imported%2Fmozilla%2Fsvg%2Fsizing%2Finline--display-inline-block--01.xhtml%20imported%2Fmozilla%2Fsvg%2Fsizing%2Finline--float-left--01.xhtml%20imported%2Fmozilla%2Fsvg%2Fsizing%2Finline--float-right--01.xhtml%20imported%2Fmozilla%2Fsvg%2Fsizing%2Finline--position-absolute--01.xhtml%20imported%2Fmozilla%2Fsvg%2Fsizing%2Finline--position-relative--01.xhtml%20imported%2Fmozilla%2Fsvg%2Fsmil%2Ftransform%2Fset-transform-1.svg%20imported%2Fmozilla%2Fsvg%2Fsmil%2Ftransform%2Ftranslate-clipPath-1.svg%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-host-namespace.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-host-rule.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-host-with-before-after.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-invisible-slot.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-nested-slot-display-override.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-slot-display-override.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-slot-fallback.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-slot-style.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-slot.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fcss-scoping-shadow-slotted-nested.html%20imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scoping%2Fshadow-host-with-before-after.html

[Radar WebKit Bug Importer]

<rdar://problem/51001306>

[Wenson Hsieh]

Sorry, I didn't see what you'd already filed a bugzilla bug :P

This should be fixed after https://trac.webkit.org/changeset/245663.

*** This bug has been marked as a duplicate of bug 198135 ***