GCC 5.1.1 thinks this is a buffer overflow: [3031/5675] Building CXX object Source...re.dir/rendering/RenderTableCell.cpp.o ../../Source/WebCore/rendering/RenderTableCell.cpp: In member function ‘void WebCore::RenderTableCell::paintCollapsedBorders(WebCore::PaintInfo&, const WebCore::LayoutPoint&)’: ../../Source/WebCore/rendering/RenderTableCell.cpp:1139:28: warning: array subscript is above array bounds [-Warray-bounds] if (m_borders[i].borderValue.exists() && m_borders[i].shouldPaint) { ^ ../../Source/WebCore/rendering/RenderTableCell.cpp:1139:65: warning: array subscript is above array bounds [-Warray-bounds] if (m_borders[i].borderValue.exists() && m_borders[i].shouldPaint) { ^