ASSERTION FAILED: mainAxisExtent - mainAxisBorderAndPaddingExtentForChild(child) >= 0 in RenderFlex…

Source/core/rendering/RenderFrameSet.cpp

 /**
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 135 matching lines @@
                 return;
         }
         yPos += m_rows.m_sizes[r];
         if (borderThickness && m_rows.m_allowBorder[r + 1]) {
             paintRowBorder(paintInfo, pixelSnappedIntRect(LayoutRect(adjustedPaintOffset.x(), adjustedPaintOffset.y() + yPos, width(), borderThickness)));
             yPos += borderThickness;
         }
     }
 }
 
+void RenderFrameSet::computePreferredLogicalWidths()
+{
+    m_minPreferredLogicalWidth = 0;
+    m_maxPreferredLogicalWidth = 0;
+    clearPreferredLogicalWidthsDirty();
+}
+
 void RenderFrameSet::GridAxis::resize(int size)
 {
     m_sizes.resize(size);
     m_deltas.resize(size);
     m_deltas.fill(0);
 
     // To track edges for resizability and borders, we need to be (size + 1). This is because a parent frameset
     // may ask us for information about our left/top/right/bottom edges in order to make its own decisions about
     // what to do. We are capable of tainting that parent frameset's borders, so we have to cache this info.
     m_preventResize.resize(size + 1);
@@ skipping 480 matching lines @@
         return SetCursor;
     }
     if (canResizeColumn(roundedPoint)) {
         cursor = columnResizeCursor();
         return SetCursor;
     }
     return RenderBox::getCursor(point, cursor);
 }
 
 } // namespace WebCore