Re-land 'Fold out-of-flow objects into anonymous blocks when removing children'

third_party/WebKit/Source/core/layout/LayoutBlock.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 357 matching lines @@
     if (startOfContinuations && startOfContinuations->styleRef().outlineStyleIsAuto())
         startOfContinuations->invalidateDisplayItemClient(*startOfContinuations);
 }
 
 void LayoutBlock::invalidateDisplayItemClients(const LayoutBoxModelObject& paintInvalidationContainer, PaintInvalidationReason invalidationReason, const LayoutRect* paintInvalidationRect) const
 {
     LayoutBox::invalidateDisplayItemClients(paintInvalidationContainer, invalidationReason, paintInvalidationRect);
     invalidateDisplayItemClientForStartOfContinuationsIfNeeded(*this);
 }
 
+static void addNextFloatingOrOutOfFlowSiblingsToBlock(LayoutBlock* block, LayoutBlock* container)
+{
+    if (block->beingDestroyed())
+        return;
+
+    LayoutObject* child = block->nextSibling();
+    while (child && child->isFloatingOrOutOfFlowPositioned()) {
+        LayoutObject* sibling = child->nextSibling();
+        container->moveChildTo(block, child, nullptr, false);
+        child = sibling;
+    }
+}
+
+static void addPreviousFloatingOrOutOfFlowSiblingsToBlock(LayoutBlock* block, LayoutBlock* container)
+{
+    if (block->beingDestroyed())
+        return;
+
+    LayoutObject* child = block->previousSibling();
+    while (child && child->isFloatingOrOutOfFlowPositioned()) {
+        LayoutObject* sibling = child->previousSibling();
+        container->moveChildTo(block, child, block->firstChild(), false);
+        child = sibling;
+    }
+}
+
 void LayoutBlock::addChildIgnoringContinuation(LayoutObject* newChild, LayoutObject* beforeChild)
 {
     if (beforeChild && beforeChild->parent() != this) {
         LayoutObject* beforeChildContainer = beforeChild->parent();
         while (beforeChildContainer->parent() != this)
             beforeChildContainer = beforeChildContainer->parent();
         ASSERT(beforeChildContainer);
 
         if (beforeChildContainer->isAnonymous()) {
             // If the requested beforeChild is not one of our children, then this is because
@@ skipping 54 matching lines @@
         if (afterChild && afterChild->isAnonymousBlock()) {
             afterChild->addChild(newChild);
             return;
         }
 
         if (newChild->isInline()) {
             // No suitable existing anonymous box - create a new one.
             LayoutBlock* newBox = createAnonymousBlock();
             LayoutBox::addChild(newBox, beforeChild);
             // Reparent adjacent floating or out-of-flow siblings to the new box.
-            LayoutObject* child = newBox->previousSibling();
-            while (child && child->isFloatingOrOutOfFlowPositioned()) {
-                LayoutObject* sibling = child->previousSibling();
-                moveChildTo(newBox, child, newBox->firstChild(), false);
-                child = sibling;
-            }
+            addPreviousFloatingOrOutOfFlowSiblingsToBlock(newBox, this);
             newBox->addChild(newChild);
-            child = newBox->nextSibling();
-            while (child && child->isFloatingOrOutOfFlowPositioned()) {
-                LayoutObject* sibling = child->nextSibling();
-                moveChildTo(newBox, child, nullptr, false);
-                child = sibling;
-            }
+            addNextFloatingOrOutOfFlowSiblingsToBlock(newBox, this);
             return;
         }
     }
 
     LayoutBox::addChild(newChild, beforeChild);
 
     if (madeBoxesNonInline && parent() && isAnonymousBlock() && parent()->isLayoutBlock())
         toLayoutBlock(parent())->removeLeftoverAnonymousBlock(this);
     // this object may be dead here
 }
@@ skipping 257 matching lines @@
         collapseAnonymousBlockChild(this, toLayoutBlock(child));
     } else if (((prev && prev->isAnonymousBlock()) || (next && next->isAnonymousBlock())) && canCollapseAnonymousBlockChild()) {
         // It's possible that the removal has knocked us down to a single anonymous
         // block with pseudo-style element siblings (e.g. first-letter). If these
         // are floating, then we need to pull the content up also.
         LayoutBlock* anonymousBlock = toLayoutBlock((prev && prev->isAnonymousBlock()) ? prev : next);
         if ((anonymousBlock->previousSibling() || anonymousBlock->nextSibling())
             && (!anonymousBlock->previousSibling() || (anonymousBlock->previousSibling()->style()->styleType() != NOPSEUDO && anonymousBlock->previousSibling()->isFloating() && !anonymousBlock->previousSibling()->previousSibling()))
             && (!anonymousBlock->nextSibling() || (anonymousBlock->nextSibling()->style()->styleType() != NOPSEUDO && anonymousBlock->nextSibling()->isFloating() && !anonymousBlock->nextSibling()->nextSibling()))) {
             collapseAnonymousBlockChild(this, anonymousBlock);
+        } else {
+            // If we have floating or out-of-flow siblings now adjacent to an anonymous block, fold them
+            // into it.
+            if (prev && prev->isAnonymousBlock())
+                addNextFloatingOrOutOfFlowSiblingsToBlock(toLayoutBlock(prev), this);
+            else if (next && next->isAnonymousBlock())
+                addPreviousFloatingOrOutOfFlowSiblingsToBlock(toLayoutBlock(next), this);
         }
     }
 
     if (!firstChild()) {
         // If this was our last child be sure to clear out our line boxes.
         if (childrenInline())
             deleteLineBoxTree();
 
         // If we are an empty anonymous block in the continuation chain,
         // we need to remove ourself and fix the continuation chain.
@@ skipping 2159 matching lines @@
 void LayoutBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const LayoutObject* obj) const
 {
     showLayoutObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink