The Qt UI continuously redrawing prevents libdecor-gtk's glib dispatch loop
from ever returning since it constantly posts new messages to draw again.
The result is that Moonlight randomly hangs (with the spinner still animating)
at the "Starting app..." phase of connection establishment and never proceeds
until the livelock is broken by loss of focus, hiding the window, or similar.
For posterity, the hanging stack:
QtWaylandClient::QWaylandWindow::waitForFrameSync (this=this@entry=..., timeout=timeout@entry=...) at qwaylandwindow.cpp:891
QtWaylandClient::QWaylandGLContext::swapBuffers (this=..., surface=...) at qwaylandglcontext.cpp:494
QRhiGles2::endFrame (this=..., swapChain=..., flags=...) at qrhigles2.cpp:2390
QRhi::endFrame (this=..., swapChain=..., flags=...) at qrhi.cpp:11600
QSGGuiThreadRenderLoop::renderWindow (this=..., window=...) at qsgrenderloop.cpp:714
QQuickWindow::event (this=..., event=...) at qquickwindow.cpp:1663
QCoreApplication::notifyInternal2 (receiver=..., event=...) at qcoreapplication.cpp:1126
QCoreApplication::sendEvent (receiver=..., event=...) at qcoreapplication.cpp:1571
QPlatformWindow::deliverUpdateRequest (this=...) at qplatformwindow.cpp:831
QObject::event (this=..., e=...) at qobject.cpp:1480
QCoreApplication::notifyInternal2 (receiver=..., event=...) at qcoreapplication.cpp:1126
QCoreApplication::sendEvent (receiver=..., event=...) at qcoreapplication.cpp:1571
QCoreApplicationPrivate::sendPostedEvents (receiver=..., event_type=..., data=...) at qcoreapplication.cpp:1926
postEventSourceDispatch (s=...) at qeventdispatcher_glib.cpp:248
g_main_dispatch (context=...) at gmain.c:3591
g_main_context_dispatch_unlocked (context=...) at gmain.c:4451
g_main_context_iterate_unlocked (context=context@entry=..., block=block@entry=..., dispatch=dispatch@entry=..., self=...) at gmain.c:4516
g_main_context_iteration (context=..., context@entry=..., may_block=may_block@entry=...) at gmain.c:4582
libdecor_plugin_gtk_dispatch (plugin=..., timeout=...) at libdecor-gtk.c:509
Wayland_PumpEvents (_this=...) at SDL_waylandevents.c:610
Wayland_GLES_LoadLibrary (_this=..., path=...) at SDL_waylandopengles.c:51
SDL_GL_LoadLibrary_REAL (path=...) at SDL_video.c:4735
SDL_RecreateWindow (window=..., flags=...) at SDL_video.c:2796
GLES2_CreateRenderer (renderer=..., window=..., create_props=...) at SDL_render_gles2.c:2329
SDL_CreateRendererWithProperties_REAL (props=props@entry=...) at SDL_render.c:1126
SDL_CreateRenderer_REAL (window=..., name=...) at SDL_render.c:1287
SDL_CreateRenderer_REAL (window=..., idx=..., flags=...) at sdl2_compat.c:5986
EGLRenderer::initialize (this=..., params=...) at eglvid.cpp:445
FFmpegVideoDecoder::initializeRendererInternal (this=..., renderer=..., params=...) at ffmpeg.cpp:323
FFmpegVideoDecoder::createFrontendRenderer (this=..., params=..., useAlternateFrontend=...) at ffmpeg.cpp:426
FFmpegVideoDecoder::completeInitialization (this=..., decoder=..., requiredFormat=..., params=..., testMode=..., useAlternateFrontend=...) at ffmpeg.cpp:486
FFmpegVideoDecoder::tryInitializeRenderer(AVCodec const*, AVPixelFormat, _DECODER_PARAMETERS*, AVCodecHWConfig const*, IFFmpegRenderer::InitFailureReason*, std::function<IFFmpegRenderer* ()>)
(this=..., decoder=..., requiredFormat=..., params=..., hwConfig=..., failureReason=..., createRendererFunc=...) at ffmpeg.cpp:1200
FFmpegVideoDecoder::tryInitializeHwAccelDecoder (this=..., params=..., pass=..., terminallyFailedHardwareDecoders=...) at ffmpeg.cpp:1544
FFmpegVideoDecoder::initialize (this=..., params=...) at ffmpeg.cpp:1701
Session::chooseDecoder (vds=..., renderer=..., window=..., videoFormat=..., width=..., height=..., frameRate=..., enableVsync=..., enableFramePacing=..., testOnly=..., chosenDecoder=...) at session.cpp:322
Session::getDecoderAvailability (window=..., vds=..., videoFormat=..., width=..., height=..., frameRate=...) at session.cpp:498
Session::initialize (this=..., qtWindow=...) at session.cpp:755
The original issue on Qt 6.7 was caused by conflicts with the window state set in main.qml
which was addressed by afbc49e39a.
The remaining issue with Qt 6.7 clobbering window state and position when hiding a window
looks like a legitimate Qt bug.
This reverts commit ebe270bec5.
- Avoids blindly enumeration all top-level windows
- Properly tracks screen changes during the connection process
- Starts stream window minimized if the Qt window was minimized
Fixes#1231