Fix Border collapsing with colpsan / rowspan cells

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)
  *
@@ skipping 946 matching lines @@
   ClearPreferredLogicalWidthsDirty();
 }
 
 LayoutTableSection* LayoutTable::TopNonEmptySection() const {
   LayoutTableSection* section = TopSection();
   if (section && !section->NumRows())
     section = SectionBelow(section, kSkipEmptySections);
   return section;
 }
 
+LayoutTableSection* LayoutTable::BottomNonEmptySection() const {
+  LayoutTableSection* section = BottomSection();
+  if (section && !section->NumRows())
+    section = SectionAbove(section, kSkipEmptySections);
+  return section;
+}
+
 void LayoutTable::SplitEffectiveColumn(unsigned index, unsigned first_span) {
   // We split the column at |index|, taking |firstSpan| cells from the span.
   DCHECK_GT(effective_columns_[index].span, first_span);
   effective_columns_.insert(index, first_span);
   effective_columns_[index + 1].span -= first_span;
 
   // 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;
@@ skipping 99 matching lines @@
           col_and_col_group.adjoins_end_border_of_col_group =
               is_at_end_edge && !col_and_col_group.col->NextSibling();
         }
       }
       return col_and_col_group;
     }
   }
   return ColAndColGroup();
 }
 
+// Maps LayoutTableCol => absoluteColumnIndex,
+// an inverse of slowColElementAtAbsoluteColumn
+unsigned LayoutTable::ColElementToAbsoluteColumn(
+    const LayoutTableCol* col_element) const {
+  unsigned col = 0;
+  for (LayoutTableCol* column_layout_object = FirstColumn();
+       column_layout_object;
+       column_layout_object = column_layout_object->NextColumn()) {
+    if (column_layout_object == col_element)
+      break;
+    if (column_layout_object->IsTableColumnGroupWithColumnChildren()) {
+      // Do nothing, span will increase with children
+    } else {
+      col += column_layout_object->Span();
+    }
+  }
+  return col;
+}
+
 void LayoutTable::RecalcSections() const {
   DCHECK(needs_section_recalc_);
 
   head_ = nullptr;
   foot_ = nullptr;
   first_body_ = nullptr;
   has_col_elements_ = false;
 
   // We need to get valid pointers to caption, head, foot and first body again
   LayoutObject* next_sibling;
@@ skipping 641 matching lines @@
 }
 
 LayoutUnit LayoutTable::PaddingRight() const {
   if (CollapseBorders())
     return LayoutUnit();
 
   return LayoutBlock::PaddingRight();
 }
 
 }  // namespace blink