Track hovered Window in DisplayServerX11

[Sauermann]

Send mouse-entered/exited window-events only when necessary

fix crash of comment #79325 (comment)
resolve for linux #80335

[Rindbee]

I tested this PR and it resolves #80335. One small problem: the mouse may teleport occasionally.

[Sauermann]

Can you provide more detail, in which situations cursor-teleports happen?
I have tested for several minutes to cause this, but was not able to.
Perhaps this is WM-related: I am using X11-Xfce.

[Rindbee]

A mouse icon appears in the center of the window when the left mouse button is released (drag to modify the value). I tried to record the screen, but failed.

This problem is reproduced in both Cinnamon and i3wm. I rebase it on 16a9356, then build with the following command: pyston-scons -j4 use_llvm=yes linker=mold dev_build=yes

[Rindbee]

This PR seems to cause a new crash:

ERROR: FATAL: DEV_ASSERT failed  "!root->gui.windowmanager_window_over" is false.
   at: _event_callback (scene/main/window.cpp:675)

================================================================
handle_crash: Program crashed with signal 4
Engine version: Godot Engine v4.2.dev.custom_build (0d54d2ba0830d18e8b0bc7d7cd9857b8fc9450c4)
Dumping the backtrace. Please include this when reporting the bug to the project developer.
[1] /lib/x86_64-linux-gnu/libc.so.6(+0x42520) [0x7f02d7442520] (??:0)
[2] Window::_event_callback(DisplayServer::WindowEvent) (/opt/godot/godot-editor-l10n/godot/scene/main/window.cpp:675)
[3] void call_with_variant_args_helper<Window, DisplayServer::WindowEvent, 0ul>(Window*, void (Window::*)(DisplayServer::WindowEvent), Variant const**, Callable::CallError&, IndexSequence<0ul>) (/opt/godot/godot-editor-l10n/godot/./core/variant/binder_common.h:308)
[4] void call_with_variant_args<Window, DisplayServer::WindowEvent>(Window*, void (Window::*)(DisplayServer::WindowEvent), Variant const**, int, Callable::CallError&) (/opt/godot/godot-editor-l10n/godot/./core/variant/binder_common.h:418)
[5] CallableCustomMethodPointer<Window, DisplayServer::WindowEvent>::call(Variant const**, int, Variant&, Callable::CallError&) const (/opt/godot/godot-editor-l10n/godot/./core/object/callable_method_pointer.h:105)
[6] Callable::callp(Variant const**, int, Variant&, Callable::CallError&) const (/opt/godot/godot-editor-l10n/godot/core/variant/callable.cpp:51)
[7] DisplayServerX11::_send_window_event(DisplayServerX11::WindowData const&, DisplayServer::WindowEvent) (/opt/godot/godot-editor-l10n/godot/platform/linuxbsd/x11/display_server_x11.cpp:3775)
[8] DisplayServerX11::process_events() (/opt/godot/godot-editor-l10n/godot/platform/linuxbsd/x11/display_server_x11.cpp:4316)
[9] OS_LinuxBSD::run() (/opt/godot/godot-editor-l10n/godot/platform/linuxbsd/os_linuxbsd.cpp:908)
[10] /opt/godot/godot-editor-l10n/godot/bin/godot.linuxbsd.editor.dev.x86_64.llvm(main+0x1fe) [0x55e79797386e] (/opt/godot/godot-editor-l10n/godot/platform/linuxbsd/godot_linuxbsd.cpp:74)
[11] /lib/x86_64-linux-gnu/libc.so.6(+0x29d90) [0x7f02d7429d90] (??:0)
[12] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x80) [0x7f02d7429e40] (??:0)
[13] /opt/godot/godot-editor-l10n/godot/bin/godot.linuxbsd.editor.dev.x86_64.llvm(_start+0x25) [0x55e7979735a5] (??:?)
-- END OF BACKTRACE --
================================================================

0.mp4

[Sauermann]

This crash is also tied to the same issue and gets resolved by #80187.

I have tried to cause the crash on Cinnamon, but even after several minutes of testing and experimenting, I was unable to replicate it.

[Rindbee]

Maybe it's due to the better performance of your device. These issues are easier to reproduce with slower builds.

A build compiled with pyston-scons -j4 keeps outputting messages similar to:

ERROR: Unhandled XServer error: BadWindow (invalid Window parameter)
   Major opcode of failed request: 2
   Serial number of failed request: 0
   Current serial number in output stream: 7914
   at: default_window_error_handler (platform/linuxbsd/x11/display_server_x11.cpp:873)

Maybe you can try a slower build, e.g. build with pyston-scons -j4 use_llvm=yes linker=mold use_ubsan=yes use_asan=yes dev_build=yes.

[Sauermann]

Finally I was able to track down the crash, that you experience @Rindbee. Updated PR is available.

[akien-mga]

Did a brief test of the PR on KDE / X11, didn't notice any issue when testing with sub-windows (detached script editor, editor settings, create dialog).

[akien-mga]

Code looks fine, and I didn't notice any obvious regression on KDE / X11.

This code can be tricky though so tests on more DEs / Wayland may be useful.

[akien-mga]

Thanks!

[gnuchanos]

x11 i just add pressed() signal
platform/linuxbsd/x11/display_server_x11.cpp:869 - Unhandled XServer error: BadWindow (invalid Window parameter)
Major opcode of failed request: 2
Serial number of failed request: 0
Current serial number in output stream: 118771
platform/linuxbsd/x11/display_server_x11.cpp:869 - Unhandled XServer error: BadWindow (invalid Window parameter)