Crash in QNetworkAccessHttpBackend::canResume ()

A number of crashes due to this stack:
Signal 11 (SIGSEGV)
0 0x3c406cb0 QNetworkAccessHttpBackend::canResume () at
access/qnetworkaccesshttpbackend.cpp:1131
1 0x3c41c910 QNetworkReplyImplPrivate::migrateBackend (this=0x705d90)
at access/qnetworkreplyimpl.cpp:917
2 0x3c41e1f8 QNetworkReplyImpl::qt_metacall (this=0x98a610, _id=-5,
_a=0x45da976c) at .moc/release-shared/moc_qnetworkreplyimpl_p.cpp:99
3 0x3bdb8428 QMetaObject::metacall (object=0x45da95b4, cl=4294716392,
idx=1011730680, argv=0x705d90) at kernel/qmetaobject.cpp:237
4 0x3bdcdf98 QMetaObject::activate (sender=0xa92e68, argv=0x705d90) at
kernel/qobject.cpp:3278
5 0x3c3fad9c QNetworkAccessManager::qt_metacall (this=0xa92e68, _id=-6,
_a=0x41dea0) at .moc/release-shared/moc_qnetworkaccessmanager.cpp:105