Fixing handling of Ligature when letter-spacing is present

Source/platform/fonts/Font.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2010, 2011 Apple 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 232 matching lines @@
 CodePath Font::codePath(const TextRun& run) const
 {
     if (s_codePath != AutoPath)
         return s_codePath;
 
 #if ENABLE(SVG_FONTS)
     if (run.renderingContext())
         return SimplePath;
 #endif
 
-    if (m_fontDescription.featureSettings() && m_fontDescription.featureSettings()->size() > 0)
+    if (m_fontDescription.featureSettings() && m_fontDescription.featureSettings()->size() > 0 && m_fontDescription.letterSpacing() == 0)
         return ComplexPath;
 
     if (run.length() > 1 && !WidthIterator::supportsTypesettingFeatures(*this))
         return ComplexPath;
 
     if (!run.characterScanForCodePath())
         return SimplePath;
 
     if (run.is8Bit())
         return SimplePath;
@@ skipping 587 matching lines @@
                 if (delta <= 0)
                     break;
             }
         }
     }
 
     return offset;
 }
 
 }