Merge 142922

Source/WebCore/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 100 matching lines @@
 
 static TrackedContainerMap* gPositionedContainerMap = 0;
 static TrackedContainerMap* gPercentHeightContainerMap = 0;
     
 typedef WTF::HashMap<RenderBlock*, OwnPtr<ListHashSet<RenderInline*> > > ContinuationOutlineTableMap;
 
 typedef WTF::HashSet<RenderBlock*> DelayedUpdateScrollInfoSet;
 static int gDelayUpdateScrollInfo = 0;
 static DelayedUpdateScrollInfoSet* gDelayedUpdateScrollInfoSet = 0;
 
-static bool gIsInColumnFlowSplit = false;
+static bool gColumnFlowSplitEnabled = true;
 
 bool RenderBlock::s_canPropagateFloatIntoSibling = false;
 
 // This class helps dispatching the 'overflow' event on layout change. overflow can be set on RenderBoxes, yet the existing code
 // only works on RenderBlocks. If this change, this class should be shared with other RenderBoxes.
 class OverflowEventDispatcher {
     WTF_MAKE_NONCOPYABLE(OverflowEventDispatcher);
 public:
     OverflowEventDispatcher(const RenderBlock* block)
         : m_block(block)
@@ skipping 697 matching lines @@
             ASSERT(beforeChild->isRunIn());
             beforeChild = beforeChildContainer;
         }
     }
 
     // Nothing goes before the intruded run-in.
     if (beforeChild && beforeChild->isRunIn() && runInIsPlacedIntoSiblingBlock(beforeChild))
         beforeChild = beforeChild->nextSibling();
 
     // Check for a spanning element in columns.
-    if (!gIsInColumnFlowSplit) {
+    if (gColumnFlowSplitEnabled) {
         RenderBlock* columnsBlockAncestor = columnsBlockForSpanningElement(newChild);
         if (columnsBlockAncestor) {
-            TemporaryChange<bool> isInColumnFlowSplit(gIsInColumnFlowSplit, true);
+            TemporaryChange<bool> columnFlowSplitEnabled(gColumnFlowSplitEnabled, false);
             // We are placing a column-span element inside a block.
             RenderBlock* newBox = createAnonymousColumnSpanBlock();
         
             if (columnsBlockAncestor != this) {
                 // We are nested inside a multi-column element and are being split by the span. We have to break up
                 // our block into continuations.
                 RenderBoxModelObject* oldContinuation = continuation();
 
                 // When we split an anonymous block, there's no need to do any continuation hookup,
                 // since we haven't actually split a real element.
@@ skipping 292 matching lines @@
 
 void RenderBlock::removeChild(RenderObject* oldChild)
 {
     // No need to waste time in merging or removing empty anonymous blocks.
     // We can just bail out if our document is getting destroyed.
     if (documentBeingDestroyed()) {
         RenderBox::removeChild(oldChild);
         return;
     }
 
+    // This protects against column split flows when anonymous blocks are getting merged.
+    TemporaryChange<bool> columnFlowSplitEnabled(gColumnFlowSplitEnabled, false);
+
     // If this child is a block, and if our previous and next siblings are
     // both anonymous blocks with inline content, then we can go ahead and
     // fold the inline content back together.
     RenderObject* prev = oldChild->previousSibling();
     RenderObject* next = oldChild->nextSibling();
     bool canMergeAnonymousBlocks = canMergeContiguousAnonymousBlocks(oldChild, prev, next);
     if (canMergeAnonymousBlocks && prev && next) {
         prev->setNeedsLayoutAndPrefWidthsRecalc();
         RenderBlock* nextBlock = toRenderBlock(next);
         RenderBlock* prevBlock = toRenderBlock(prev);
@@ skipping 6683 matching lines @@
 {
     memoryInstrumentation->addRootObject(gColumnInfoMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gPositionedDescendantsMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gPercentHeightDescendantsMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gPositionedContainerMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gPercentHeightContainerMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gDelayedUpdateScrollInfoSet, WebCoreMemoryTypes::RenderingStructures);
 }
 
 } // namespace WebCore