Merge patch for stacked floats with shape-outside from WebKit

Source/core/rendering/RenderBlockLineLayout.cpp

Index: Source/core/rendering/RenderBlockLineLayout.cpp
diff --git a/Source/core/rendering/RenderBlockLineLayout.cpp b/Source/core/rendering/RenderBlockLineLayout.cpp
index e3e1da8245bfadf54a2d1745862f63f05d5d5a4a..ee10a74b5b2468ebcc1445cb33de0a5c717d12c1 100644
--- a/Source/core/rendering/RenderBlockLineLayout.cpp
+++ b/Source/core/rendering/RenderBlockLineLayout.cpp
@@ -181,6 +181,28 @@ inline void LineWidth::shrinkAvailableWidthForNewFloatIfNeeded(RenderBlock::Floa
         return;
 
 #if ENABLE(CSS_EXCLUSIONS)

[Julien - ping for review, 2013/04/17 21:20:22]

We should probably remove these.

+    // When floats with shape outside are stacked, the floats are positioned based on the bounding box of the shape,
+    // not the shape's contour. Since we computed the width based on the shape contour when we added the float,
+    // when we add a subsequent float on the same line, we need to undo the shape delta in order to position
+    // based on the bounding box. In order to do this, we need to walk back through the floating object list to find
+    // the first previous float that is on the same side as our newFloat.
+    ExclusionShapeOutsideInfo* previousShapeOutsideInfo = 0;
+    const RenderBlock::FloatingObjectSet& floatingObjectSet = m_block->m_floatingObjects->set();
+    RenderBlock::FloatingObjectSetIterator it = floatingObjectSet.end();
+    RenderBlock::FloatingObjectSetIterator begin = floatingObjectSet.begin();
+    while (it != begin) {
+        --it;
+        RenderBlock::FloatingObject* previousFloat = *it;
+        if (previousFloat != newFloat && previousFloat->type() == newFloat->type()) {
+            previousShapeOutsideInfo = previousFloat->renderer()->exclusionShapeOutsideInfo();
+            if (previousShapeOutsideInfo) {
+                LayoutUnit lineTopInShapeCoordinates = m_block->logicalHeight() - m_block->logicalTopForFloat(previousFloat) + previousShapeOutsideInfo->shapeLogicalTop();
+                previousShapeOutsideInfo->computeSegmentsForLine(lineTopInShapeCoordinates, logicalHeightForLine(m_block, m_isFirstLine));
+            }
+            break;
+        }
+    }
+
     ExclusionShapeOutsideInfo* shapeOutsideInfo = newFloat->renderer()->exclusionShapeOutsideInfo();
     if (shapeOutsideInfo)
         shapeOutsideInfo->computeSegmentsForLine(m_block->logicalHeight() - m_block->logicalTopForFloat(newFloat) + shapeOutsideInfo->shapeLogicalTop(), logicalHeightForLine(m_block, m_isFirstLine));
@@ -189,6 +211,8 @@ inline void LineWidth::shrinkAvailableWidthForNewFloatIfNeeded(RenderBlock::Floa
     if (newFloat->type() == RenderBlock::FloatingObject::FloatLeft) {
         float newLeft = m_block->logicalRightForFloat(newFloat);
 #if ENABLE(CSS_EXCLUSIONS)
+        if (previousShapeOutsideInfo)
+            newLeft -= previousShapeOutsideInfo->rightSegmentShapeBoundingBoxDelta();
         if (shapeOutsideInfo)
             newLeft += shapeOutsideInfo->rightSegmentShapeBoundingBoxDelta();
 #endif
@@ -199,6 +223,8 @@ inline void LineWidth::shrinkAvailableWidthForNewFloatIfNeeded(RenderBlock::Floa
     } else {
         float newRight = m_block->logicalLeftForFloat(newFloat);
 #if ENABLE(CSS_EXCLUSIONS)
+        if (previousShapeOutsideInfo)
+            newRight -= previousShapeOutsideInfo->leftSegmentShapeBoundingBoxDelta();
         if (shapeOutsideInfo)
             newRight += shapeOutsideInfo->leftSegmentShapeBoundingBoxDelta();
 #endif