x11 FindChild fails during a call to CreateHostWindow

[Czarek]

In CEF v66 I have problem with browser creation crashing with PyQt4 and PySide apps (based on Qt4). It works fine in PyQt5 and wxPython apps, but not with Qt4. It worked fine in CEF v57 and there weren't any code modifications in my app, only CEF was upgraded. The stack trace is following:

Code: Select all

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff1d9e0bf in FindChild () at ../../cef/libcef/browser/native/window_x11.cc:44
44   ../../cef/libcef/browser/native/window_x11.cc: No such file or directory.
(gdb) bt
#0  0x00007ffff1d9e0bf in FindChild () at ../../cef/libcef/browser/native/window_x11.cc:44
#1  Show () at ../../cef/libcef/browser/native/window_x11.cc:178
#2  0x00007ffff1d9aa57 in CreateHostWindow ()
    at ../../cef/libcef/browser/native/browser_platform_delegate_native_linux.cc:89
#3  0x00007ffff1cb5879 in CreateHostWindow () at ../../cef/libcef/browser/browser_host_impl.cc:3159
#4  CreateInternal () at ../../cef/libcef/browser/browser_host_impl.cc:418
#5  0x00007ffff1cb436f in Create () at ../../cef/libcef/browser/browser_host_impl.cc:359
#6  0x00007ffff1cb3b3d in CreateBrowserSync () at ../../cef/libcef/browser/browser_host_impl.cc:275


Here are the corresponding CEF source codes for the stack trace:
0. https://github.com/chromiumembedded/cef ... x11.cc#L44
1. https://github.com/chromiumembedded/cef ... 11.cc#L178
2. https://github.com/chromiumembedded/cef ... nux.cc#L89
3. https://github.com/chromiumembedded/cef ... l.cc#L3159
4. https://github.com/chromiumembedded/cef ... pl.cc#L418
5. https://github.com/chromiumembedded/cef ... pl.cc#L359
6. https://github.com/chromiumembedded/cef ... pl.cc#L275

The parent window in which CEF browser is embedded is shown and realized.

Any idea of what could go wrong? Thank your for help.

CEF 3359, Ubuntu 14.04.

[magreenblatt]

Looks like XQueryTree is returning no children (it should have a child DesktopWindowTreeHostX11 created by Chromium). In any case the code should be fixed not to crash.

[Czarek]

Created issue:
https://bitbucket.org/chromiumembedded/ ... -a-call-to

[loki]

Hi
I have the same issue, but with different configuration.
I have host app based on SDL2, and I am trying to create browser this way:

Code: Select all

    CefWindowInfo window_info;
    window_info.SetAsChild((cef_window_handle_t)window_handle, GetRectWebForm(window_handle, w, h));

    auto manager = CefCookieManager::GetGlobalManager(nullptr);
    manager->SetStoragePath(CEF_CACHE_FOLDER, false, nullptr);

    CefBrowserSettings browser_settings;

    CefBrowserHost::CreateBrowser(window_info, this, url, browser_settings, NULL);


where window_handle is X11::Window.

My app crashes in FindChild with SEGFAULT.
Any idia how to fix this?

[Czarek]

@loki I have attached a patch in the tracker: https://bitbucket.org/chromiumembedded/ ... t-49187953

[loki]

But the current code assums that there is always 1 child window (according to DCHECK_EQ(1U, nchildren);).
Will be all fine if FindChild return x11::None?

[Czarek]

Yes, it works.

[loki]

Thank you, I will try.