Abs-positioned objects should move with inline rel-positioned containers when the latter change wid…

Source/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 1912 matching lines @@
         } else {
             // Our object was a block originally, so we make our normal flow position be
             // just below the line box (as though all the inlines that came before us got
             // wrapped in an anonymous block, which is what would have happened had we been
             // in flow).  This value was cached in the y() of the box.
             layer()->setStaticBlockPosition(box->logicalTop());
             if (style()->hasStaticBlockPosition(box->isHorizontal()))
                 setChildNeedsLayout(MarkOnlyThis); // Just go ahead and mark the positioned object as needing layout, so it will update its position properly.
         }
 
+        if (container()->isRenderInline())
+            moveWithEdgeOfInlineContainerIfNecessary(box->isHorizontal());
+
         // Nuke the box.
         box->remove(DontMarkLineBoxes);
         box->destroy();
     } else if (isReplaced()) {
         setLocation(roundedLayoutPoint(box->topLeft()));
         setInlineBoxWrapper(box);
     }
 }
 
+void RenderBox::moveWithEdgeOfInlineContainerIfNecessary(bool isHorizontal)
+{
+    ASSERT(isOutOfFlowPositioned() && container()->isRenderInline() && container()->isRelPositioned());
+    // If this object is inside a relative positioned inline and its inline position is an explicit offset from the edge of its container
+    // then it will need to move if its inline container has changed width. We do not track if the width has changed
+    // but if we are here then we are laying out lines inside it, so it probably has - mark our object for layout so that it can
+    // move to the new offset created by the new width.
+    if (!normalChildNeedsLayout() && !style()->hasStaticInlinePosition(isHorizontal))
+        setChildNeedsLayout(MarkOnlyThis);
+}
+
 void RenderBox::deleteLineBoxWrapper()
 {
     if (inlineBoxWrapper()) {
         if (!documentBeingDestroyed())
             inlineBoxWrapper()->remove();
         inlineBoxWrapper()->destroy();
         ASSERT(m_rareData);
         m_rareData->m_inlineBoxWrapper = 0;
     }
 }
@@ skipping 2717 matching lines @@
 
         // We need the old border box size only when the box has background or box decorations.
         if (!style()->hasBackground() && !style()->hasBoxDecorations())
             return;
     }
 
     ensureRareData().m_previousBorderBoxSize = size();
 }
 
 } // namespace blink