Bug 303208 – [GTK][WPE] Layout test imported/blink/fast/pagination/viewport-y-horizontal-bt-rtl.html is flaky

• Status: NEW
• Component: WPE WebKit

[Carlos Alberto Lopez Perez]

The layout test imported/blink/fast/pagination/viewport-y-horizontal-bt-rtl.html is flaky on both WPE and GTK and it has been 


For GTK it has been flaky since a long time ago


$ ./wktesthunter --all --m imported/blink/fast/pagination/viewport-y-horizontal-bt-rtl.html

[...]

The bot gtk-release completed 12683 runs on the interval [250001@main-303567@main]
Frecuency of results for test: imported/blink/fast/pagination/viewport-y-horizontal-bt-rtl.html
  12281 times [96.8%]    ->  NOERROR
  99 times [0.8%]        ->  IMAGE PASS
  303 times [2.4%]       ->  IMAGE

Of those 12683 runs it didn't match the expectation 402 times [3.2%]
Details of the type and frequency of unmatched expectations:
  99 times [0.8%]        ->  IMAGE PASS (Expected: PASS)
  303 times [2.4%]       ->  IMAGE (Expected: PASS)



For WPE it started to have a flaky behavior around 270640@main and since then is as flaky as on GTK


$ ./wktesthunter --bot wpe-release imported/blink/fast/pagination/viewport-y-horizontal-bt-rtl.html

[...]

The bot wpe-release completed 1013 runs on the interval [299574@main-303567@main]
Frecuency of results for test: imported/blink/fast/pagination/viewport-y-horizontal-bt-rtl.html
  994 times [98.1%]      ->  NOERROR
  19 times [1.9%]        ->  IMAGE

Of those 1013 runs it didn't match the expectation 19 times [1.9%]
Details of the type and frequency of unmatched expectations:
  19 times [1.9%]        ->  IMAGE (Expected: PASS)


If you check the diff https://build.webkit.org/results/WPE-Linux-64-bit-Release-Tests/303556@main%20(24039)/imported/blink/fast/pagination/viewport-y-horizontal-bt-rtl-diffs.html

The problem is that sometimes a scrollbar is rendered at the right and sometimes not for the test, but the reftest-expectation doesn't expect this scrollbar at the right to be drawn.

[Carlos Alberto Lopez Perez]

(In reply to Carlos Alberto Lopez Perez from comment #0)

> The problem is that sometimes a scrollbar is rendered at the right and
> sometimes not for the test, but the reftest-expectation doesn't expect this
> scrollbar at the right to be drawn.

Sorry, is the other way around, the scrollbar at the right is expected to be drawn, but sometimes it doesn't drawn it

I market as flaky in https://commits.webkit.org/303613@main

[Carlos Alberto Lopez Perez]

Perhaps this is related with bug 303855