KItemListView::setAlternateBackgrounds(bool) (kitemlistview.cpp:489)
In C++, a data member of an object is not automatically initialized to "zero".
In this case a bool had random values such as the integer 255.
QGraphicsWidget(parent),
m_enabledSelectionToggles(false),
m_grouped(false),
+ m_highlightEntireRow(false),
+ m_alternateBackgrounds(false),
m_supportsItemExpanding(false),
m_editingRole(false),
m_activeTransactions(0),
m_visibleItems(),
m_visibleGroups(),
m_visibleCells(),
+ m_scrollBarExtent(0),
m_layouter(nullptr),
m_animation(nullptr),
m_oldScrollOffset(0),