Fix table cell background painting

third_party/WebKit/Source/core/layout/LayoutTable.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, 2007, 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 716 matching lines @@
 }
 
 LayoutTableSection* LayoutTable::topNonEmptySection() const
 {
     LayoutTableSection* section = topSection();
     if (section && !section->numRows())
         section = sectionBelow(section, SkipEmptySections);
     return section;
 }
 
+LayoutTableSection* LayoutTable::bottomNonEmptySection() const
+{
+    LayoutTableSection* section = bottomSection();
+    if (section && !section->numRows())
+        section = sectionAbove(section, SkipEmptySections);
+    return section;
+}
+
 void LayoutTable::splitEffectiveColumn(unsigned index, unsigned firstSpan)
 {
     // We split the column at |index|, taking |firstSpan| cells from the span.
     ASSERT(m_effectiveColumns[index].span > firstSpan);
     m_effectiveColumns.insert(index, firstSpan);
     m_effectiveColumns[index + 1].span -= firstSpan;
 
     // Propagate the change in our columns representation to the sections that don't need
     // cell recalc. If they do, they will be synced up directly with m_columns later.
     for (LayoutObject* child = firstChild(); child; child = child->nextSibling()) {
@@ skipping 90 matching lines @@
                     colAndColGroup.adjoinsStartBorderOfColGroup = isAtStartEdge && !colAndColGroup.col->previousSibling();
                     colAndColGroup.adjoinsEndBorderOfColGroup = isAtEndEdge && !colAndColGroup.col->nextSibling();
                 }
             }
             return colAndColGroup;
         }
     }
     return ColAndColGroup();
 }
 
+unsigned LayoutTable::colElementToAbsoluteColumn(const LayoutTableCol* colElement) const
+{
+    unsigned col = 0;
+
+    for (LayoutTableCol* columnLayoutObject = firstColumn(); columnLayoutObject; columnLayoutObject = columnLayoutObject->nextColumn()) {
+        if (columnLayoutObject == colElement)
+            return col;
+        if (columnLayoutObject->isTableColumnGroupWithColumnChildren()) {
+            // Count spans of leaf col elements only.
+        } else {
+            col += columnLayoutObject->span();
+        }
+    }
+    ASSERT_NOT_REACHED();
+    return 0;
+}
+
 void LayoutTable::recalcSections() const
 {
     ASSERT(m_needsSectionRecalc);
 
     m_head = nullptr;
     m_foot = nullptr;
     m_firstBody = nullptr;
     m_hasColElements = false;
     m_hasCellColspanThatDeterminesTableWidth = hasCellColspanThatDeterminesTableWidth();
 
@@ skipping 604 matching lines @@
 
 LayoutUnit LayoutTable::paddingRight() const
 {
     if (collapseBorders())
         return LayoutUnit();
 
     return LayoutBlock::paddingRight();
 }
 
 } // namespace blink