*** DO NOT LAND *** Implement column-span:all without reparenting renderers. Work in progress.

Source/core/rendering/RenderMultiColumnSpannerSet.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 "config.h"
 #include "core/rendering/RenderMultiColumnSpannerSet.h"
 
 namespace blink {
 
 // RenderMultiColumnSpannerSet follows:
 
 RenderMultiColumnSpannerSet* RenderMultiColumnSpannerSet::createAnonymous(RenderMultiColumnFlowThread* flowThread, RenderStyle* parentStyle, RenderBox* renderer)
 {
     RenderMultiColumnSpannerSet* newSpanner = new RenderMultiColumnSpannerSet(flowThread, renderer);
     Document& document = flowThread->document();
     newSpanner->setDocumentForAnonymous(&document);
-    newSpanner->setStyle(RenderStyle::createAnonymousStyleWithDisplay(parentStyle, BLOCK));
+    RefPtr<RenderStyle> newStyle = RenderStyle::createAnonymousStyleWithDisplay(parentStyle, BLOCK);
+    newSpanner->updateMarginProperties(newStyle.get(), renderer);
+    newSpanner->setStyle(newStyle);
     return newSpanner;
 }
 
 RenderMultiColumnSpannerSet::RenderMultiColumnSpannerSet(RenderMultiColumnFlowThread* flowThread, RenderBox* renderer)
     : RenderMultiColumnSet(flowThread)
     , m_renderer(renderer)
 {
 }
 
+void RenderMultiColumnSpannerSet::updateMarginProperties(RenderStyle* newStyle, const RenderObject* spannerBlock) const
+{
+    RefPtr<RenderStyle> spannerBlockStyle = spannerBlock->style();
+    newStyle->setMarginTop(spannerBlockStyle->marginTop());
+    newStyle->setMarginBottom(spannerBlockStyle->marginBottom());
+    newStyle->setMarginLeft(spannerBlockStyle->marginLeft());
+    newStyle->setMarginRight(spannerBlockStyle->marginRight());
+}
+
 bool RenderMultiColumnSpannerSet::recalculateColumnHeight(BalancedHeightCalculation calculationMode)
 {
-    m_columnHeight = m_renderer->logicalHeight() + m_renderer->marginLogicalHeight();
+    m_columnHeight = m_renderer->logicalHeight();
     return false;
 }
 
 void RenderMultiColumnSpannerSet::computeLogicalHeight(LayoutUnit, LayoutUnit logicalTop, LogicalExtentComputedValues& computedValues) const
 {
-    computedValues.m_extent = m_renderer->logicalHeight() + m_renderer->marginLogicalHeight();
-    computedValues.m_position = logicalTop;
+    computedValues.m_extent = m_renderer->logicalHeight();
+    computedValues.m_position = logicalTop + m_renderer->marginTop();
+    computedValues.m_margins.m_before = marginBefore();
+    computedValues.m_margins.m_after = marginAfter();
 }
 
 LayoutUnit RenderMultiColumnSpannerSet::pageLogicalHeight() const
 {
-    return m_renderer->logicalHeight() + m_renderer->marginLogicalHeight();
+    return m_renderer->logicalHeight();
 }
 
 const char* RenderMultiColumnSpannerSet::renderName() const
 {
     return "RenderMultiColumnSpannerSet";
 }
 
 }