Bug 217741 – REGRESSION (r268178): [iOS] imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-multiple-times.html is a flaky failure

• Status: NEW
• Component: Images

[Ryan Haddad]

imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-multiple-times.html is a flaky failure on iOS bots after https://trac.webkit.org/changeset/268178 landed

--- /Volumes/Data/slave/ios-simulator-14-release-tests-wk2/build/layout-test-results/imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-multiple-times-expected.txt
+++ /Volumes/Data/slave/ios-simulator-14-release-tests-wk2/build/layout-test-results/imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-multiple-times-actual.txt
@@ -1,4 +1,4 @@
 
 
-PASS Images with loading='lazy' can be lazy loaded multiple times
+FAIL Images with loading='lazy' can be lazy loaded multiple times assert_unreached: The loading=lazy below-viewport image should lazily load its second image, and not load it eagerly when the `src` attribute is changed Reached unreachable code
 
https://results.webkit.org/?suite=layout-tests&test=imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-multiple-times.html

[Radar WebKit Bug Importer]

<rdar://problem/70313927>

[Karl Rackler]

REPRODUCTION STEPS
I can reproduce this on 268217, but unable to reproduce on 268154.
Commit r268178 has to do with changing the test expectation, which could have introduced the flakiness.  The change was introduced here https://trac.webkit.org/changeset/268178/webkit.


Command: 
run-webkit-tests --ios-simulator --iterations 50 --exit-after-n-failures 1 --exit-after-n-crashes-or-timeouts 1 imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-multiple-times.html

Result: 
Regressions: Unexpected text-only failures (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-multiple-times.html [ Failure ]

[Rob Buis]

This is not unexpected, as the logic is tricky, but I wonder if the same problem also happens on OS X. I will have a look tomorrow.

[Aakash Jain]

Interesting that https://ews-build.webkit.org/#/builders/24/builds/27659 also says: Found flaky test: imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-multiple-times.html

[Karl Rackler]

I have marked this test as failing while this issue is investigated.
https://trac.webkit.org/changeset/268524/webkit

[Karl Rackler]

This reverts commit r268178 because it caused a test failure.
https://trac.webkit.org/changeset/268619/webkit

https://trac.webkit.org/changeset/269217/webkit
Remove test expectation after revert of r268178.