Fix paint invalidation rects for repeating paginated table headers.

third_party/WebKit/Source/core/layout/LayoutTableSection.cpp

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1672 matching lines @@
 
     // FIXME: The table's direction should determine our row's direction, not the section's (see bug 96691).
     if (!style()->isLeftToRightDirection())
         cellLocation.setX(LayoutUnit(table()->effectiveColumnPositions()[table()->numEffectiveColumns()] - table()->effectiveColumnPositions()[table()->absoluteColumnToEffectiveColumn(cell->absoluteColumnIndex() + cell->colSpan())] + horizontalBorderSpacing));
     else
         cellLocation.setX(LayoutUnit(table()->effectiveColumnPositions()[effectiveColumn] + horizontalBorderSpacing));
 
     cell->setLogicalLocation(cellLocation);
 }
 
+bool LayoutTableSection::hasRepeatingHeaderGroup() const
+{
+    if (getPaginationBreakability() == LayoutBox::AllowAnyBreaks)
+        return false;
+    // TODO(rhogan): Should we paint a header repeatedly if it's self-painting?
+    if (hasSelfPaintingLayer())
+        return false;
+    LayoutUnit pageHeight = table()->pageLogicalHeightForOffset(LayoutUnit());
+    if (!pageHeight)
+        return false;
+    return true;
+}
+
+bool LayoutTableSection::mapToVisualRectInAncestorSpace(const LayoutBoxModelObject* ancestor, LayoutRect& rect, VisualRectFlags flags) const
+{
+    if (ancestor == this)
+        return true;
+    // Repeating table headers are painted once per fragmentation page/column. This does not go through the regular fragmentation machinery,
+    // so we need special code to expand the invalidation rect to contain all positions of the header in all columns.
+    // Note that this is in flow thread coordinates, not visual coordinates. The enclosing LayoutFlowThread will convert to visual coordinates.
+    if (table()->header() == this && hasRepeatingHeaderGroup())
+        rect.setHeight(table()->logicalHeight());
+    return LayoutTableBoxComponent::mapToVisualRectInAncestorSpace(ancestor, rect, flags);
+}
+
+
 } // namespace blink