https://trac.webkit.org/changeset/178029 made compositing tests crash on EFL which made the EFL bot early exit and unable to catch any new regression. Unfortunately the EFL bot was out of order r178020-r178142, but I bisected manually and confirm that r178029 caused this serious regression. Crash logs can be found here: (at least for a month, will be deleted automatically) https://build.webkit.org/builders/EFL%20Linux%2064-bit%20Release%20WK2/builds/18835
I have found the call stack of crash from your link <https://build.webkit.org/builders/EFL%20Linux%2064-bit%20Release%20WK2/builds/18835 >. 18:59:49.163 21071 worker/3 compositing/backing/no-backing-for-clip-overlap.html crashed, (stderr lines): 18:59:49.163 21071 1 0x7ffb1cebf8c0 18:59:49.163 21071 2 0x7ffb1d080c30 18:59:49.163 21071 3 0x7ffb1ed33c85 WebCore::CoordinatedGraphicsLayer::notifyFlushRequired() 18:59:49.163 21071 4 0x7ffb1ed37b45 WebCore::CoordinatedGraphicsLayer::removeFromParent() 18:59:49.164 21071 5 0x7ffb1ed361b2 WebCore::CoordinatedGraphicsLayer::~CoordinatedGraphicsLayer() 18:59:49.164 21071 6 0x7ffb1ed36791 WebCore::CoordinatedGraphicsLayer::~CoordinatedGraphicsLayer() 18:59:49.164 21071 7 0x7ffb1ead6ecc WebCore::RenderLayerBacking::updateChildClippingStrategy(bool) 18:59:49.164 21071 8 0x7ffb1ead7131 WebCore::RenderLayerBacking::~RenderLayerBacking() 18:59:49.164 21071 9 0x7ffb1ead72a1 WebCore::RenderLayerBacking::~RenderLayerBacking() 18:59:49.164 21071 10 0x7ffb1eacacf2 WebCore::RenderLayer::clearBacking(bool) 18:59:49.164 21071 11 0x7ffb1eacae4d WebCore::RenderLayer::~RenderLayer() 18:59:49.164 21071 12 0x7ffb1eacb0f1 WebCore::RenderLayer::~RenderLayer() 18:59:49.164 21071 13 0x7ffb1eb1095f WebCore::RenderObject::willBeDestroyed() 18:59:49.164 21071 14 0x7ffb1eb133f9 WebCore::RenderObject::destroy() I can confirm that crash happens when clearing childClippingMaskLayer of CoordinatedGraphics Layer as in the following code. 1433 void RenderLayerBacking::updateChildClippingStrategy(bool needsDescendentsClippingLayer) 1434 { ................ 1453 } else { 1454 if (m_childClippingMaskLayer) { 1455 m_childClippingMaskLayer = nullptr; I am investigating the reason why it makes crash on EFL port.
Created attachment 244342 [details] Patch
(In reply to comment #2) > Created attachment 244342 [details] > Patch I checked this patch locally, it fixes the EFL issue for me.
Comment on attachment 244342 [details] Patch Clearing flags on attachment: 244342 Committed r178176: <http://trac.webkit.org/changeset/178176>
All reviewed patches have been landed. Closing bug.