[New Multicolumn] Intrinsic/preferred logical width calculation for spanners.

Source/core/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 2938 matching lines @@
 {
     if (childrenInline()) {
         // FIXME: Remove this const_cast.
         toRenderBlockFlow(const_cast<RenderBlock*>(this))->computeInlinePreferredLogicalWidths(minLogicalWidth, maxLogicalWidth);
     } else {
         computeBlockPreferredLogicalWidths(minLogicalWidth, maxLogicalWidth);
     }
 
     maxLogicalWidth = std::max(minLogicalWidth, maxLogicalWidth);
 
-    adjustIntrinsicLogicalWidthsForColumns(minLogicalWidth, maxLogicalWidth);
+    // The new ("region based") multicol implementation will do this adjustment on the flow thread,

[Julien - ping for review, 2015/01/27 09:31:37]

Let's remove the use of 'new' as we will want to switch soonish.

[mstensho (USE GERRIT), 2015/01/27 10:20:23]

Done.

+    // and not here on the multicol container, so that spanners won't incorrectly be treated as
+    // column content (and have spanners' preferred widths multiplied by the number of columns, etc.).
+    if (style()->specifiesColumns() && !document().regionBasedColumnsEnabled())
+        adjustIntrinsicLogicalWidthsForColumns(minLogicalWidth, maxLogicalWidth);
 
     if (isTableCell()) {
         Length tableCellWidth = toLayoutTableCell(this)->styleOrColLogicalWidth();
         if (tableCellWidth.isFixed() && tableCellWidth.value() > 0)
             maxLogicalWidth = std::max(minLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(tableCellWidth.value()));
     }
 
     int scrollbarWidth = intrinsicScrollbarLogicalWidth();
     maxLogicalWidth += scrollbarWidth;
     minLogicalWidth += scrollbarWidth;
@@ skipping 64 matching lines @@
 
 void RenderBlock::computeBlockPreferredLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
 {
     RenderStyle* styleToUse = style();
     bool nowrap = styleToUse->whiteSpace() == NOWRAP;
 
     RenderObject* child = firstChild();
     RenderBlock* containingBlock = this->containingBlock();
     LayoutUnit floatLeftWidth = 0, floatRightWidth = 0;
     while (child) {
-        // Positioned children don't affect the min/max width
-        if (child->isOutOfFlowPositioned()) {
+        // Positioned children don't affect the min/max width. Spanners only affect the min/max
+        // width of the multicol container, not the flow thread.
+        if (child->isOutOfFlowPositioned() || child->isColumnSpanAll()) {
             child = child->nextSibling();
             continue;
         }
 
         RefPtr<RenderStyle> childStyle = child->style();
         if (child->isFloating() || (child->isBox() && toRenderBox(child)->avoidsFloats())) {
             LayoutUnit floatTotalWidth = floatLeftWidth + floatRightWidth;
             if (childStyle->clear() & CLEFT) {
                 maxLogicalWidth = std::max(floatTotalWidth, maxLogicalWidth);
                 floatLeftWidth = 0;
@@ skipping 20 matching lines @@
 
         LayoutUnit childMinPreferredLogicalWidth, childMaxPreferredLogicalWidth;
         if (child->isBox() && child->isHorizontalWritingMode() != isHorizontalWritingMode()) {
             RenderBox* childBox = toRenderBox(child);
             LogicalExtentComputedValues computedValues;
             childBox->computeLogicalHeight(childBox->borderAndPaddingLogicalHeight(), 0, computedValues);
             childMinPreferredLogicalWidth = childMaxPreferredLogicalWidth = computedValues.m_extent;
         } else {
             childMinPreferredLogicalWidth = child->minPreferredLogicalWidth();
             childMaxPreferredLogicalWidth = child->maxPreferredLogicalWidth();
+            if (child->isRenderFlowThread()) {
+                // The preferred intrinsic widths that a flow thread reports pertains to the column
+                // width, but here we want the preferred multicol container width, so we need to
+                // adjust with that in mind.
+                adjustIntrinsicLogicalWidthsForColumns(childMinPreferredLogicalWidth, childMaxPreferredLogicalWidth);
+            }
         }
 
         LayoutUnit w = childMinPreferredLogicalWidth + margin;
         minLogicalWidth = std::max(w, minLogicalWidth);
 
         // IE ignores tables for calculation of nowrap. Makes some sense.
         if (nowrap && !child->isTable())
             maxLogicalWidth = std::max(w, maxLogicalWidth);
 
         w = childMaxPreferredLogicalWidth + margin;
@@ skipping 845 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink