Don't repeat headers if at least one row of content doesn't fit

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 982 matching lines @@
         // Set the row's x/y position and width/height.
         LayoutTableRow* rowLayoutObject = m_grid[r].rowLayoutObject;
         int paginationStrutOnRow = 0;
         if (rowLayoutObject) {
             rowLayoutObject->setLocation(LayoutPoint(0, m_rowPos[r]));
             rowLayoutObject->setLogicalWidth(logicalWidth());
             rowLayoutObject->setLogicalHeight(LayoutUnit(m_rowPos[r + 1] - m_rowPos[r] - vspacing));
             rowLayoutObject->updateLayerTransformAfterLayout();
             if (isPaginated) {
                 paginationStrutOnRow = paginationStrutForRow(rowLayoutObject, LayoutUnit(m_rowPos[r]));
+                rowLayoutObject->setHasPaginationStrut(paginationStrutOnRow);
                 if (paginationStrutOnRow) {
                     // If there isn't room for at least one content row on a page with a header group, then
                     // we won't repeat the header on each page.
-                    if (!r && table()->header() && table()->sectionAbove(this) == table()->header())
+                    if (!r && table()->header() && table()->sectionAbove(this) == table()->header() && table()->header()->getPaginationBreakability() != AllowAnyBreaks)
                         state.setHeightOffsetForTableHeaders(state.heightOffsetForTableHeaders() - table()->header()->logicalHeight());
                     // If we have a header group we will paint it at the top of each page, move the rows
                     // down to accomodate it.
                     paginationStrutOnRow += state.heightOffsetForTableHeaders().toInt();
                     for (unsigned rowIndex = r; rowIndex <= totalRows; rowIndex++)
                         m_rowPos[rowIndex] += paginationStrutOnRow;
                 }
             }
         }
 
@@ skipping 692 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
+bool LayoutTableSection::isRepeatingHeaderGroup() 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;
 
     if (logicalHeight() > pageHeight)
         return false;
 
     // If the first row of the section after the header group doesn't fit on the page, then
     // don't repeat the header on each page. See https://drafts.csswg.org/css-tables-3/#repeated-headers
     LayoutTableSection* sectionBelow = table()->sectionBelow(this);
-    if (sectionBelow && sectionBelow->firstRow() && sectionBelow->paginationStrutForRow(sectionBelow->firstRow(), sectionBelow->logicalTop()))

[rhogan, 2016/09/12 19:07:35]

We don't get a valid result from paginationStrutForRow() when we're not in
layout.

[mstensho (USE GERRIT), 2016/09/13 06:51:36]

Why is that?

+    if (sectionBelow && sectionBelow->firstRow() && sectionBelow->firstRow()->hasPaginationStrut())
         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())
+    if (table()->header() == this && isRepeatingHeaderGroup())
         rect.setHeight(table()->logicalHeight());
     return LayoutTableBoxComponent::mapToVisualRectInAncestorSpace(ancestor, rect, flags);
 }
 
 
 } // namespace blink