Crash in Qt model code

[Kev]

thread #1: tid = 0x29dff2, 0x00007fff8e8bb866 libsystem_kernel.dylib`__pthread_kill + 10, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
frame #0: 0x00007fff8e8bb866 libsystem_kernel.dylib`__pthread_kill + 10
frame #1: 0x00007fff8d3e435c libsystem_pthread.dylib`pthread_kill + 92
frame #2: 0x00007fff89929b1a libsystem_c.dylib`abort + 125
frame #3: 0x00007fff898f39bf libsystem_c.dylib`__assert_rtn + 321
frame #4: 0x00000001000a867a Eve-Xin`boost::enable_shared_from_this<EveXin::SkillItem>::shared_from_this() + 170
frame #5: 0x0000000100111cec Eve-Xin`EveXin::QtSkillModel::getItem(this=0x000000010c0432f0, index=0x00000001048ff090) const + 156 at QtSkillModel.cpp:114
frame #6: 0x0000000100115277 Eve-Xin`EveXin::QtSkillModel::parent(this=0x000000010c0432f0, child=0x00000001048ff090) const + 119 at QtSkillModel.cpp:199
frame #7: 0x0000000101771145 QtWidgets`QTreeView::drawRow(QPainter*, QStyleOptionViewItem const&, QModelIndex const&) const + 117
frame #8: 0x000000010176fec6 QtWidgets`QTreeView::drawTree(QPainter*, QRegion const&) const + 902
frame #9: 0x000000010176fb15 QtWidgets`QTreeView::paintEvent(QPaintEvent*) + 325
frame #10: 0x00000001015545e6 QtWidgets`QWidget::event(QEvent*) + 1958
frame #11: 0x00000001016328c7 QtWidgets`QFrame::event(QEvent*) + 183
frame #12: 0x00000001016affba QtWidgets`QAbstractScrollArea::viewportEvent(QEvent*) + 122
frame #13: 0x000000010173321f QtWidgets`QAbstractItemView::viewportEvent(QEvent*) + 1391
frame #14: 0x000000010176f898 QtWidgets`QTreeView::viewportEvent(QEvent*) + 520
frame #15: 0x00000001016b0ab5 QtWidgets`QAbstractScrollAreaFilter::eventFilter(QObject*, QEvent*) + 37
frame #16: 0x0000000100c8e3ac QtCore`QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) + 156
frame #17: 0x000000010151bf19 QtWidgets`QApplicationPrivate::notify_helper(QObject*, QEvent*) + 281
frame #18: 0x000000010151ea1d QtWidgets`QApplication::notify(QObject*, QEvent*) + 6157
frame #19: 0x0000000100c8e0b2 QtCore`QCoreApplication::notifyInternal(QObject*, QEvent*) + 114
frame #20: 0x000000010154f29a QtWidgets`QWidgetPrivate::drawWidget(QPaintDevice*, QRegion const&, QPoint const&, int, QPainter*, QWidgetBackingStore*) + 2890
frame #21: 0x00000001015278fa QtWidgets`QWidgetBackingStore::sync() + 3066
frame #22: 0x0000000101546a13 QtWidgets`QWidgetPrivate::syncBackingStore() + 211
frame #23: 0x000000010155488a QtWidgets`QWidget::event(QEvent*) + 2634
frame #24: 0x0000000101648807 QtWidgets`QMainWindow::event(QEvent*) + 935
frame #25: 0x000000010151bf2c QtWidgets`QApplicationPrivate::notify_helper(QObject*, QEvent*) + 300
frame #26: 0x000000010151ea1d QtWidgets`QApplication::notify(QObject*, QEvent*) + 6157
frame #27: 0x0000000100c8ec07 QtCore`QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) + 631
frame #28: 0x0000000103f1a4c0 libqcocoa.dylib`QCocoaEventDispatcherPrivate::processPostedEvents() + 288
frame #29: 0x0000000103f1afd8 libqcocoa.dylib`QCocoaEventDispatcherPrivate::postedEventsSourceCallback(void*) + 40
frame #30: 0x00007fff8a9235b1 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
frame #31: 0x00007fff8a914c62 CoreFoundation`__CFRunLoopDoSources0 + 242
frame #32: 0x00007fff8a9143ef CoreFoundation`__CFRunLoopRun + 831
frame #33: 0x00007fff8a913e75 CoreFoundation`CFRunLoopRunSpecific + 309
frame #34: 0x00007fff8beb6a0d HIToolbox`RunCurrentEventLoopInMode + 226
frame #35: 0x00007fff8beb67b7 HIToolbox`ReceiveNextEventCommon + 479
frame #36: 0x00007fff8beb65bc HIToolbox`_BlockUntilNextEventMatchingListInModeWithFilter + 65
frame #37: 0x00007fff9208524e AppKit`_DPSNextEvent + 1434
frame #38: 0x00007fff9208489b AppKit`-[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 122
frame #39: 0x00007fff9207899c AppKit`-[NSApplication run] + 553
frame #40: 0x0000000103f19d44 libqcocoa.dylib`QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 2404
frame #41: 0x0000000100c8b64d QtCore`QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 397
frame #42: 0x0000000100c8e652 QtCore`QCoreApplication::exec() + 354
frame #43: 0x0000000100001d8a Eve-Xin`main + 2090
frame #44: 0x00007fff8995a5fd libdyld.dylib`start + 1
frame #45: 0x00007fff8995a5fd libdyld.dylib`start + 1