(gdb) where
#0  0x000055555556c571 in std::__atomic_base<int>::load(std::memory_order) const (this=0x1c, __m=std::memory_order_relaxed) at /usr/include/c++/7/bits/atomic_base.h:396
#1  0x00007ffff15e52ca in QAtomicOps<int>::load<int>(std::atomic<int> const&) (_q_value=...) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qatomic_cxx11.h:227
#2  0x00007ffff15e49f8 in QBasicAtomicInteger<int>::load() const (this=0x1c) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qbasicatomic.h:102
#3  0x00007ffff1b27be5 in QWeakPointer<QObject>::isNull() const (this=0x55555ef74170) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qsharedpointer_impl.h:562
#4  0x00007ffff1b27482 in QPointer<QWidget>::isNull() const (this=0x55555ef74170) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qpointer.h:95
#5  0x00007ffff1b2530c in QgsSearchHighlightOptionWidget::reset() (this=0x55555ef74160) at /home/webmaster/dev/cpp/QGIS/src/gui/qgsoptionsdialogbase.cpp:478