It happens when attaching a new web process, because it tries to encode a null SessionState. #0 0x00007ffff4a40263 in WebKit::WebBackForwardListItem::encode(IPC::ArgumentEncoder&) const () from libwebkit2gtk-3.0.so.25 #1 0x00007ffff4a340d4 in WebKit::LegacySessionState::encode(IPC::ArgumentEncoder&) const () from libwebkit2gtk-3.0.so.25 #2 0x00007ffff4a54ae2 in WebKit::WebPageCreationParameters::encode(IPC::ArgumentEncoder&) const () from libwebkit2gtk-3.0.so.25 #3 0x00007ffff4ac5679 in bool WebKit::ChildProcessProxy::send<Messages::WebProcess::CreateWebPage>(Messages::WebProcess::CreateWebPage&&, unsigned long, unsigned int) () from libwebkit2gtk-3.0.so.25 #4 0x00007ffff4aba790 in WebKit::WebPageProxy::initializeWebPage() () from libwebkit2gtk-3.0.so.25 #5 0x00007ffff4ababbb in WebKit::WebPageProxy::reattachToWebProcess() () from libwebkit2gtk-3.0.so.25 #6 0x00007ffff4abb608 in WebKit::WebPageProxy::loadAlternateHTMLString(WTF::String const&, WTF::String const&, WTF::String const&, API::Object*) () from libwebkit2gtk-3.0.so.25 #7 0x00007ffff4bdd190 in webkit_web_view_load_alternate_html () from libwebkit2gtk-3.0.so.25 I guess EFL is affected as well.
Created attachment 234247 [details] Patch
Comment on attachment 234247 [details] Patch LGTM
Committed r170748: <http://trac.webkit.org/changeset/170748>