176881 2017-09-13 16:25:12 -0700 REGRESSION (r164015): Layout Test plugins/js-from-destroy.html is flaky 2018-02-05 15:07:12 -0800 1 1 1 Unclassified WebKit Plug-ins WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED https://bugs.webkit.org/show_bug.cgi?id=181889 InRadar, Regression P2 Normal --- 128712 1 jlewis3 webkit-unassigned ap dbates rniwa webkit-bug-importer oldest_to_newest 1348550 0 jlewis3 2017-09-13 16:25:12 -0700 plugins/js-from-destroy.html is a flaky failure on macOS according to the flakiness dashboard: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=plugins%2Fjs-from-destroy.html Results: https://build.webkit.org/results/Apple%20Sierra%20Debug%20WK2%20(Tests)/r221995%20(3021)/results.html https://build.webkit.org/builders/Apple%20Sierra%20Debug%20WK2%20(Tests)/builds/3021 Diff: --- /Volumes/Data/slave/sierra-debug-tests-wk2/build/layout-test-results/plugins/js-from-destroy-expected.txt +++ /Volumes/Data/slave/sierra-debug-tests-wk2/build/layout-test-results/plugins/js-from-destroy-actual.txt @@ -1 +1,2 @@ +CONSOLE MESSAGE: XMLHttpRequest cannot load due to access control checks. PASS if didn't crash. 1348816 1 ap 2017-09-14 10:04:07 -0700 Is this leaking from a preceding test? 1360967 2 jlewis3 2017-10-16 14:53:50 -0700 I was able to reproduce the failure with: run-webkit-tests --no-retry-failure --iterations=50 plugins/js-from-destroy.html 1361241 3 webkit-bug-importer 2017-10-17 08:40:47 -0700 <rdar://problem/35029828> 1362854 4 jlewis3 2017-10-20 13:58:54 -0700 Marked as Flaky in: https://trac.webkit.org/changeset/223793/webkit/ 1391279 5 dbates 2018-01-19 16:29:59 -0800 The cause of the flakiness is <https://trac.webkit.org/changeset/164015> (bug #128712). We have not supported JavaScript evaluation from NPP_Destroy() on macOS for Out-of-Process plugins for many years now. We disallowed such behavior in <https://trac.webkit.org/changeset/42789> and <https://trac.webkit.org/changeset/62279> (bug #41431). We should make WebKit match the behavior the OOP plugins on macOS and then change the test plugins/js-from-destroy.html and others to ensure that we do not allow JavaScript evaluation from NPP_Destroy(). See bug #181889 for more details. Additional remarks: Plugin tests that evaluate JavaScript from NPP_Destroy() have been flaky in WebKit since <https://trac.webkit.org/changeset/164015> (bug #128712). Following r164015 when NPP_Destroy() is called there is a racy between the time the PluginProcess's response reaches the WebProcess and it invalidates the PluginProcess connection and the PluginProcess sends a synchronous message to the WebProcess to evaluate the JavaScript specified in the ondestroy handler of an <embed>. Depending on who wins the race the ondestroy handler may or may not be invoked => a console message may or may not be in the result for the test plugins/js-from-destroy.html. 1396568 6 dbates 2018-02-05 14:58:48 -0800 Following <https://trac.webkit.org/changeset/228100> (bug #181889) test plugins/js-from-destroy.html is marked WontFix for both WebKit2 and Mac WebKit1 as both WebKit and WebKit Legacy on Mac do not allow JavaScript execution from NPP_Destroy(). 1396573 7 dbates 2018-02-05 15:07:12 -0800 (In reply to Daniel Bates from comment #6) > Following <https://trac.webkit.org/changeset/228100> (bug #181889) test > plugins/js-from-destroy.html is marked WontFix for both WebKit2 and Mac > WebKit1 as both WebKit and WebKit Legacy on Mac do not allow JavaScript > execution from NPP_Destroy(). Elaborating further, plugins/js-from-destroy.html is no longer flaky following <https://trac.webkit.org/changeset/228100> when run. It is marked WontFix because it no longer tests anything meaningful in WebKit2 and Mac WebKit1 since the we longer allow JavaScript execution from NPP_Destroy(), which was what this test was testing. There is still some value in keeping plugins/js-from-destroy.html in the tree for WebKit Legacy on Windows.