sporadic CRASH on exit in QNetworkConfigurationManagerPrivate::pollEngines() on unixes (corrupt stack?)

ok. Yes, I don't see any errors related to that while running musescore. But a crash on exit is still a crash and a potential source or indicator of bad things, so I'm going to keep my eye out. Which is why I've set priority to normal, not critical.

what distoro and cpu are you on?

See the QNetworkReplyImplPrivate::error at mscore start in console?

Or see the QNetworkConfigurationManagerPrivate::pollEngines() when quit mscore?

If this is same, then we can say is not just an ArchLinuxARMv7 issue, but a linux CPU-independent issue.

I have seen the crash on exit quite a few times before on my other linux, but I never bothered to investigate, nor have caught it in QtCreator.

OK. I'm changing title to reflect that this is a general linux issue.

Googling for QNetworkConfigurationManagerPrivate::pollEngines segfault reveals that a lot of other projects outside of MuseScore experience this same sporadic issue:

https://lists.debian.org/debian-qt-kde/2015/11/msg00221.html

Apparently something was fixed in Qt 5.4.2 https://codereview.qt-project.org/#/c/111893/ but I'm using 5.5.1 so apparently that didn't fix it completely, or it is a separate issue. Should I try contacting Qt?

regarding the QNetworkReplyImplPrivate::error on startup, I'm noticing on my x86-64 Win 8.1 machine running master that I'm also getting that:

Warning: QNetworkReplyImplPrivate::error: Internal problem, this method must only be called once. (:0, )

I still have no idea whether these two errors are related in any way.

Thanks!

Has anyone experienced this crash on Windows?

I've experienced the crash on my i686 arch linux machine running official arch build of mscore 2.0.2. All I did was open mscore, edit preferences, close mscore, and then I see the telltale:

QNetworkReplyImplPrivate::error: Internal problem, this method must only be called once.

I've attached output of "gdb /usr/bin/mscore -coredump-" with "thread apply all bt" but I think the interesting bit is:

Program terminated with signal SIGSEGV, Segmentation fault.
#0  0xb36f39fe in QNetworkConfigurationManagerPrivate::pollEngines() () from /usr/lib/libQt5Network.so.5
[Current thread is 1 (Thread 0xa7b5cb40 (LWP 1107))]
(gdb) thread apply all bt

Thread 9 (Thread 0xaebaeb40 (LWP 1106)):
#0  0xb770ec11 in __kernel_vsyscall ()
#1  0xb2268cef in poll () from /usr/lib/libc.so.6
#2  0xb0ad6fcd in ?? () from /usr/lib/libxcb.so.1
#3  0xb0ad914b in xcb_wait_for_event () from /usr/lib/libxcb.so.1
#4  0xaed73f23 in ?? ()
#5  0x0b4acf78 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)

I've added "(corrupt stack?)" to this bug title.

I've saved this coredump and backtrace (and will save future coredumps) to: https://efjz.in/index.php/s/DllKY9veK8m2FAP

EDIT: I'll try what lasonic says to diable webkit with "-w", and I'll see if I still get any crash on exit. I'm noting that I at least no longer see the "QNetworkReplyImplPrivate::error".

Running shoogle's latest nightly i686 AppImage (without encountering crash), I notice console output:

QObject::connect: Cannot connect (null)::stateChanged(QNetworkSession::State) to QNetworkReplyHttpImpl::_q_networkSessionStateChanged(QNetworkSession::State)
QObject::connect: Cannot connect (null)::stateChanged(QNetworkSession::State) to QNetworkReplyHttpImpl::_q_networkSessionStateChanged(QNetworkSession::State)
QObject::connect: Cannot connect (null)::stateChanged(QNetworkSession::State) to QNetworkReplyHttpImpl::_q_networkSessionStateChanged(QNetworkSession::State)
QObject::connect: Cannot connect (null)::stateChanged(QNetworkSession::State) to QNetworkReplyHttpImpl::_q_networkSessionStateChanged(QNetworkSession::State)
QObject::connect: Cannot connect (null)::stateChanged(QNetworkSession::State) to QNetworkReplyHttpImpl::_q_networkSessionStateChanged(QNetworkSession::State)
QObject::connect: Cannot connect (null)::stateChanged(QNetworkSession::State) to QNetworkReplyHttpImpl::_q_networkSessionStateChanged(QNetworkSession::State)
QObject::connect: Cannot connect (null)::stateChanged(QNetworkSession::State) to QNetworkReplyHttpImpl::_q_networkSessionStateChanged(QNetworkSession::State)
QNetworkReplyImplPrivate::error: Internal problem, this method must only be called once.
QObject::connect: Cannot connect (null)::stateChanged(QNetworkSession::State) to QNetworkReplyHttpImpl::_q_networkSessionStateChanged(QNetworkSession::State)

So maybe there is some issue connecting something. (I think those connect messages are referring to singals & slots...someone correct me if mistaken)

APPENDUM: note that the first "Cannot connect" error appears when start screen first displays, but at that point no "Mastering MuseScore" visual appears, untill a couple seconds later, at which point the rest of those console messages appear all at once.

In windows 8.1 x86-64 git master I do receive on startup:

Warning: QNetworkReplyImplPrivate::error: Internal problem, this method must only be called once. (:0, )

So clearly that issue is on all platforms...I'm going to try to fix that...