230141 2021-09-09 18:02:48 -0700 [Win] ASSERTION FAILED: ::IsWindow(m_viewWindow) in WebView::initWithFrame 2021-09-16 18:03:14 -0700 1 1 1 Unclassified WebKit WebKit Misc. WebKit Nightly Build Unspecified Unspecified NEW InRadar P2 Normal --- 1 fujii webkit-unassigned webkit-bug-importer oldest_to_newest 1792192 0 fujii 2021-09-09 18:02:48 -0700 [Win] ASSERTION FAILED: ::IsWindow(m_viewWindow) in WebView::initWithFrame WinCairo debug is randomly crashing for editing/pasteboard/paste-contents-with-side-effects.html recently. Regressions: Unexpected crashes (2) editing/pasteboard/paste-contents-with-side-effects.html [ Crash ] ASSERTION FAILED: ::IsWindow(m_viewWindow) ..\..\Source\WebKitLegacy\win\WebView.cpp(3076) : WebView::initWithFrame 1 00007FF8F95D1E8A WTFCrash 2 00007FF8C51C4381 WTFCrashWithInfo 3 00007FF8C53445E1 WebView::initWithFrame 4 00007FF8F7C02BCF createWebViewAndOffscreenWindow 5 00007FF8F7C51A6F UIDelegate::createWebViewWithRequest 6 00007FF8C539C64B WebChromeClient::createWindow 7 00007FF8C896F99E WebCore::Chrome::createWindow 8 00007FF8C87F3168 WebCore::createWindow 9 00007FF8C8999478 WebCore::DOMWindow::createWindow 10 00007FF8C898F378 WebCore::DOMWindow::open 11 00007FF8C5D346CF WebCore::jsDOMWindowInstanceFunction_openBody 12 00007FF8C5D5AB39 WebCore::IDLOperation<WebCore::JSDOMWindow>::call<&WebCore::jsDOMWindowInstanceFunction_openBody,0> 13 00007FF8C5CBBC39 WebCore::jsDOMWindowInstanceFunction_open 14 000002012B1911BE 241340@main: First red 241304@main: Last green Buildbot: builder WinCairo-64-bit-WKL-Debug-Tests build 932 https://build.webkit.org/#/builders/32/builds/932 1792211 1 fujii 2021-09-09 19:27:25 -0700 Running the test case can't reproduce this assertion failure on my PC. r282255 marked it in TestExpectations. 1793187 2 fujii 2021-09-13 21:05:27 -0700 r282376 marked it flaky. 1794289 3 webkit-bug-importer 2021-09-16 18:03:14 -0700 <rdar://problem/83221300>