Refactor avoidsFloats() to reflect CSS2.1 spec more clearly

Source/core/rendering/RenderBlockFlow.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 881 matching lines @@
         const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
         FloatingObjectSetIterator end = floatingObjectSet.end();
         for (FloatingObjectSetIterator it = floatingObjectSet.begin(); it != end; ++it) {
             FloatingObject* floatingObject = it->get();
             if (!floatingObject->isDescendant())
                 oldIntrudingFloatSet.add(floatingObject->renderer());
         }
     }
 
     // Inline blocks are covered by the isReplaced() check in the avoidFloats method.
-    if (avoidsFloats() || isDocumentElement() || isRenderView() || isFloatingOrOutOfFlowPositioned() || isTableCell()) {
+    if (avoidsOrIgnoresFloats() || isRenderView()) {
         if (m_floatingObjects) {
             m_floatingObjects->clear();
         }
         if (!oldIntrudingFloatSet.isEmpty())
             markAllDescendantsWithFloatsForLayout();
         return;
     }
 
     RendererToFloatInfoMap floatMap;
 
     if (m_floatingObjects) {
         if (childrenInline())
             m_floatingObjects->moveAllToFloatInfoMap(floatMap);
         else
             m_floatingObjects->clear();
     }
 
     // We should not process floats if the parent node is not a RenderBlockFlow. Otherwise, we will add
     // floats in an invalid context. This will cause a crash arising from a bad cast on the parent.
     // See <rdar://problem/8049753>, where float property is applied on a text node in a SVG.
     if (!parent() || !parent()->isRenderBlockFlow())
         return;
 
     // Attempt to locate a previous sibling with overhanging floats. We skip any elements that
     // may have shifted to avoid floats, and any objects whose floats cannot interact with objects
     // outside it (i.e. objects that create a new block formatting context).
     RenderBlockFlow* parentBlockFlow = toRenderBlockFlow(parent());
     bool parentHasFloats = false;
     RenderObject* prev = previousSibling();
-    while (prev && (!prev->isBox() || !prev->isRenderBlock() || toRenderBlock(prev)->avoidsFloats() || toRenderBlock(prev)->createsBlockFormattingContext())) {
+    while (prev && (!prev->isBox() || !prev->isRenderBlock() || toRenderBlock(prev)->avoidsOrIgnoresFloats())) {
         if (prev->isFloating())
             parentHasFloats = true;
         prev = prev->previousSibling();
     }
 
     // First add in floats from the parent. Self-collapsing blocks let their parent track any floats that intrude into
     // them (as opposed to floats they contain themselves) so check for those here too.
     LayoutUnit logicalTopOffset = logicalTop();
     bool parentHasIntrudingFloats = !parentHasFloats && (!prev || toRenderBlockFlow(prev)->isSelfCollapsingBlock()) && parentBlockFlow->lowestFloatLogicalBottom() > logicalTopOffset;
     if (parentHasFloats || parentHasIntrudingFloats)
@@ skipping 888 matching lines @@
 
 void RenderBlockFlow::markSiblingsWithFloatsForLayout(RenderBox* floatToRemove)
 {
     if (!m_floatingObjects)
         return;
 
     const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
     FloatingObjectSetIterator end = floatingObjectSet.end();
 
     for (RenderObject* next = nextSibling(); next; next = next->nextSibling()) {
-        if (!next->isRenderBlockFlow() || next->isFloatingOrOutOfFlowPositioned() || toRenderBlockFlow(next)->avoidsFloats())
+        if (!next->isRenderBlockFlow() || avoidsOrIgnoresFloats())
             continue;
 
         RenderBlockFlow* nextBlock = toRenderBlockFlow(next);
         for (FloatingObjectSetIterator it = floatingObjectSet.begin(); it != end; ++it) {
             RenderBox* floatingBox = (*it)->renderer();
             if (floatToRemove && floatingBox != floatToRemove)
                 continue;
             if (nextBlock->containsFloat(floatingBox))
                 nextBlock->markAllDescendantsWithFloatsForLayout(floatingBox);
         }
@@ skipping 58 matching lines @@
 }
 
 void RenderBlockFlow::createFloatingObjects()
 {
     m_floatingObjects = adoptPtr(new FloatingObjects(this, isHorizontalWritingMode()));
 }
 
 void RenderBlockFlow::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
 {
     RenderStyle* oldStyle = style();
-    s_canPropagateFloatIntoSibling = oldStyle ? !isFloatingOrOutOfFlowPositioned() && !avoidsFloats() : false;
+    s_canPropagateFloatIntoSibling = oldStyle ? !avoidsOrIgnoresFloats() : false;

[rhogan, 2014/11/11 19:17:13]

I had !createsBlockFormattingContext() here; which is consistent with the logic
elsewhere. This seems like a good candidate for the cause of the crash in bug
388757 (which I can't recreate).

     if (oldStyle && parent() && diff.needsFullLayout() && oldStyle->position() != newStyle.position()
         && containsFloats() && !isFloating() && !isOutOfFlowPositioned() && newStyle.hasOutOfFlowPosition())
             markAllDescendantsWithFloatsForLayout();
 
     RenderBlock::styleWillChange(diff, newStyle);
 }
 
 void RenderBlockFlow::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 {
     RenderBlock::styleDidChange(diff, oldStyle);
 
     // After our style changed, if we lose our ability to propagate floats into next sibling
     // blocks, then we need to find the top most parent containing that overhanging float and
     // then mark its descendants with floats for layout and clear all floats from its next
     // sibling blocks that exist in our floating objects list. See bug 56299 and 62875.
-    bool canPropagateFloatIntoSibling = !isFloatingOrOutOfFlowPositioned() && !avoidsFloats();
+    bool canPropagateFloatIntoSibling = !avoidsOrIgnoresFloats();
     if (diff.needsFullLayout() && s_canPropagateFloatIntoSibling && !canPropagateFloatIntoSibling && hasOverhangingFloats()) {
         RenderBlockFlow* parentBlockFlow = this;
         const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
         FloatingObjectSetIterator end = floatingObjectSet.end();
 
         for (RenderObject* curr = parent(); curr && !curr->isRenderView(); curr = curr->parent()) {
             if (curr->isRenderBlockFlow()) {
                 RenderBlockFlow* currBlock = toRenderBlockFlow(curr);
 
                 if (currBlock->hasOverhangingFloats()) {
@@ skipping 756 matching lines @@
 void RenderBlockFlow::setPaginationStrut(LayoutUnit strut)
 {
     if (!m_rareData) {
         if (!strut)
             return;
         m_rareData = adoptPtrWillBeNoop(new RenderBlockFlowRareData(this));
     }
     m_rareData->m_paginationStrut = strut;
 }
 
-bool RenderBlockFlow::avoidsFloats() const
-{
-    // Floats can't intrude into our box if we have a non-auto column count or width.
-    // Note: we need to use RenderBox::avoidsFloats here since RenderBlock::avoidsFloats is always true.
-    return RenderBox::avoidsFloats() || !style()->hasAutoColumnCount() || !style()->hasAutoColumnWidth();
-}
-
 LayoutUnit RenderBlockFlow::logicalLeftSelectionOffset(const RenderBlock* rootBlock, LayoutUnit position) const
 {
     LayoutUnit logicalLeft = logicalLeftOffsetForLine(position, false);
     if (logicalLeft == logicalLeftOffsetForContent())
         return RenderBlock::logicalLeftSelectionOffset(rootBlock, position);
 
     const RenderBlock* cb = this;
     while (cb != rootBlock) {
         logicalLeft += cb->logicalLeft();
         cb = cb->containingBlock();
@@ skipping 114 matching lines @@
     FrameView* frameView = document().view();
     LayoutUnit top = (style()->position() == FixedPosition) ? 0 : frameView->scrollOffset().height();
     int visibleHeight = frameView->visibleContentRect(IncludeScrollbars).height();
     if (height() < visibleHeight)
         top += (visibleHeight - height()) / 2;
     setY(top);
     dialog->setCentered(top);
 }
 
 } // namespace blink