Fix nested unicode-bidi: isolate

Source/core/rendering/RenderBlockLineLayout.cpp

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google Inc. 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
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 1291 matching lines @@
         // itself to be turned into an InlineBox. We can't remove it here without potentially losing track of
         // the logically last run.
         if (isolatedResolver.runs().runCount())
             bidiRuns.replaceRunWithRuns(isolatedRun, isolatedResolver.runs());
 
         // If we encountered any nested isolate runs, just move them
         // to the top resolver's list for later processing.
         if (!isolatedResolver.isolatedRuns().isEmpty()) {
             topResolver.isolatedRuns().append(isolatedResolver.isolatedRuns());
             isolatedResolver.isolatedRuns().clear();
+            currentRoot = isolatedInline;
         }
     }
 }
 
 static inline bool segmentIsEmpty(const InlineIterator& segmentStart, const InlineIterator& segmentEnd)
 {
     return segmentStart == segmentEnd;
 }
 
 static inline void constructBidiRunsForLine(const RenderBlock* block, InlineBidiResolver& topResolver, BidiRunList<BidiRun>& bidiRuns, const InlineIterator& endOfLine, VisualDirectionOverride override, bool previousLineBrokeCleanly)
@@ skipping 2158 matching lines @@
     lineGridBox->alignBoxesInBlockDirection(logicalHeight(), textBoxDataMap, verticalPositionCache);
 
     setLineGridBox(lineGridBox);
 
     // FIXME: If any of the characteristics of the box change compared to the old one, then we need to do a deep dirtying
     // (similar to what happens when the page height changes). Ideally, though, we only do this if someone is actually snapping
     // to this grid.
 }
 
 }