Bug 153038

Modern IDB: A few cursor tests are flaky because JS wrappers are GC'ed storage/indexeddb/cursor-update.html storage/indexeddb/mutating-cursor.html https://build.webkit.org/results/Apple%20Yosemite%20Release%20WK1%20(Tests)/r194903%20(11144)/results.html https://build.webkit.org/results/Apple%20Yosemite%20Release%20WK1%20(Tests)/r194901%20(11142)/results.html You can see on the flakiness dashboard that on debug bots they are crashes: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#tests=storage%2Findexeddb%2Fmutating-cursor.html But really ASSERTs. I verified running these tests repeatedly with some logging that the IDBRequest answered "false" to hasPendingActivity(), leading to its JS wrapper to get GC'ed, but then an event was delivered. The ASSERTs in debug builds are just that: inline JSC::JSObject* JSEventListener::jsFunction(ScriptExecutionContext* scriptExecutionContext) const ... ASSERT(!m_isolatedWorld->isNormal() || m_wrapper || !m_jsFunction); IDBRequests for cursors operations can be reused and must maintain a "true" answer to this question while a cursor operation is outstanding.