Dear Maintainer,
I tried to reproduce this issue and found a difference between
a minimal Bookworm VM with just running jwm window manager and my
regular Plasma desktop.
In the minimal VM a `kstart5 kcalc` returns immediately,
while at my regular Plasma desktop it blocks until the started
application is closed.
I found in the non-blocking case `KStart::windowAdded` gets executed
and therefore `QCoreApplication::exit` is called.
This seems to be caused by having useRule to be true
in the `KStart::KStart` constructor,
and therefore the connect call is not reached.
Kind regards,
Bernhard
(rr) bt
#0 0x00007ffb802b1860 in QCoreApplication::exit
(returnCode=returnCode@entry=0) at kernel/qcoreapplication.cpp:1430
#1 0x000055a5e93fd065 in KStart::windowAdded (this=0x7fff2864b760, w=6291470)
at ./kstart/kstart.cpp:201
#2 0x00007ffb802e8f4f in QtPrivate::QSlotObjectBase::call (a=0x7fff2864adc0,
r=0x7fff2864b760, this=0x55a5e9b58230) at
../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#3 doActivate<false> (sender=0x7ffb8174a440 <(anonymous
namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>, signal_index=4,
argv=0x7fff2864adc0) at kernel/qobject.cpp:3923
#4 0x00007ffb802e21ef in QMetaObject::activate (sender=sender@entry=0x7ffb8174a440
<(anonymous namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>,
m=m@entry=0x7ffb81748700 <KWindowSystem::staticMetaObject>,
local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7fff2864adc0) at
kernel/qobject.cpp:3983
#5 0x00007ffb8170e522 in KWindowSystem::windowAdded (this=this@entry=0x7ffb8174a440
<(anonymous namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>,
_t1=<optimized out>, _t1@entry=6291470) at
./obj-x86_64-linux-gnu/src/KF5WindowSystem_autogen/EWIEGA46WW/moc_kwindowsystem.cpp:409
#6 0x00007ffb7b07363d in NETEventFilter::addClient (this=0x55a5e9b6baf0,
w=6291470) at ./src/platforms/xcb/kwindowsystem.cpp:412
#7 0x00007ffb8172ea51 in NETRootInfo::update (this=0x55a5e9b6baf0,
properties=..., properties2=...) at ./src/platforms/xcb/netwm.cpp:2033
#8 0x00007ffb7b071af7 in NETEventFilter::activate (this=<optimized out>) at
./src/platforms/xcb/kwindowsystem.cpp:183
#9 KWindowSystemPrivateX11::init (this=this@entry=0x7ffb74006730,
what=what@entry=KWindowSystemPrivateX11::INFO_BASIC) at
./src/platforms/xcb/kwindowsystem.cpp:575
#10 0x00007ffb7b071d4c in KWindowSystemPrivateX11::connectNotify
(this=0x7ffb74006730, signal=...) at ./src/platforms/xcb/kwindowsystem.cpp:536
#11 0x00007ffb8171fc35 in KWindowSystem::connectNotify (this=0x7ffb8174a440
<(anonymous namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>,
signal=...) at ./src/kwindowsystem.cpp:380
#12 0x00007ffb802dea6a in QObjectPrivate::connectImpl (sender=sender@entry=0x7ffb8174a440
<(anonymous namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>, signal_index=4,
receiver=receiver@entry=0x7fff2864b760, slot=slot@entry=0x7fff2864b670,
slotObj=slotObj@entry=0x55a5e9b58230, type=<optimized out>, types=<optimized out>,
senderMetaObject=<optimized out>) at kernel/qobject.cpp:5108
#13 0x00007ffb802ded45 in QObject::connectImpl (sender=0x7ffb8174a440 <(anonymous
namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>,
signal=signal@entry=0x7fff2864b660, receiver=receiver@entry=0x7fff2864b760,
slot=slot@entry=0x7fff2864b670, slotObj=0x55a5e9b58230, type=Qt::AutoConnection, types=0x0,
senderMetaObject=<optimized out>) at kernel/qobject.cpp:5038
#14 0x000055a5e93fc7bb in QObject::connect<void (KWindowSystem::*)(unsigned long long), void
(KStart::*)(unsigned long long)> (type=Qt::AutoConnection, slot=(void (KStart::*)(KStart * const,
unsigned long long)) 0x55a5e93fcfc0 <KStart::windowAdded(unsigned long long)>,
receiver=0x7fff2864b760, signal=(void (KWindowSystem::*)(KWindowSystem * const, unsigned long long))
0x7ffb8170e4e0 <KWindowSystem::windowAdded(unsigned long long)>, sender=<optimized out>) at
/usr/include/x86_64-linux-gnu/qt5/QtCore/qobject.h:268
#15 KStart::KStart (this=0x7fff2864b760) at ./kstart/kstart.cpp:78
#16 0x000055a5e93fac84 in main (argc=<optimized out>, argv=<optimized out>) at
./kstart/kstart.cpp:424
kde-cli-tools-5.27.2/kstart/kstart.cpp
62 KStart::KStart()
63 : QObject()
64 {
65 bool useRule = false;
66
67 #ifdef HAVE_X11
68 if (QX11Info::isPlatformX11()) {
69 NETRootInfo i(QX11Info::connection(), NET::Supported);
70 useRule = i.isSupported(NET::WM2KDETemporaryRules);
71 }
72 #endif
73
74 if (useRule) {
75 sendRule();
76 } else {
77 // connect to window add to get the NEW windows
78 connect(KWindowSystem::self(), &KWindowSystem::windowAdded, this,
&KStart::windowAdded);
79 }
