Handle nested theads correctly when paginated

third_party/WebKit/Source/core/paint/TableSectionPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/TableSectionPainter.h"
 
 #include "core/layout/LayoutTableCell.h"
 #include "core/layout/LayoutTableCol.h"
 #include "core/layout/LayoutTableRow.h"
 #include "core/paint/BoxClipper.h"
@@ skipping 37 matching lines @@
         return;
 
     LayoutPoint paginationOffset = paintOffset;
     // Move paginationOffset to the top of the second page.
     paginationOffset.move(0, pageHeight - table->pageLogicalOffset());
     // Now move paginationOffset to the top of the page the cull rect starts on.
     if (paintInfo.cullRect().m_rect.y() > paginationOffset.y())
         paginationOffset.move(0, pageHeight * static_cast<int>((paintInfo.cullRect().m_rect.y() - paginationOffset.y()) / pageHeight));
     LayoutUnit bottomBound = std::min(LayoutUnit(paintInfo.cullRect().m_rect.maxY()), paintOffset.y() + table->logicalHeight());
     while (paginationOffset.y() < bottomBound) {
+        LayoutPoint nestedOffset = paginationOffset + LayoutPoint(0, m_layoutTableSection.offsetForRepeatingHeader());
         if (itemToPaint == PaintCollapsedBorders)
-            paintCollapsedSectionBorders(paintInfo, paginationOffset, currentBorderValue);
+            paintCollapsedSectionBorders(paintInfo, nestedOffset, currentBorderValue);
         else
-            paintSection(paintInfo, paginationOffset);
+            paintSection(paintInfo, nestedOffset);
         paginationOffset.move(0, pageHeight);
     }
 }
 
 void TableSectionPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     paintSection(paintInfo, paintOffset);
     LayoutTable* table = m_layoutTableSection.table();
     if (table->header() == m_layoutTableSection)
         paintRepeatingHeaderGroup(paintInfo, paintOffset, CollapsedBorderValue(), PaintSection);
@@ skipping 226 matching lines @@
     DisplayItem::Type type = shadowStyle == Normal ? DisplayItem::TableSectionBoxShadowNormal : DisplayItem::TableSectionBoxShadowInset;
     if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(paintInfo.context, m_layoutTableSection, type))
         return;
 
     LayoutRect bounds = BoxPainter(m_layoutTableSection).boundsForDrawingRecorder(paintOffset);
     LayoutObjectDrawingRecorder recorder(paintInfo.context, m_layoutTableSection, type, bounds);
     BoxPainter::paintBoxShadow(paintInfo, LayoutRect(paintOffset, m_layoutTableSection.size()), m_layoutTableSection.styleRef(), shadowStyle);
 }
 
 } // namespace blink