Check for null selectors when looping in findBestRuleSetAndAdd

Source/core/css/CSSSelector.cpp

 /*
  * Copyright (C) 1999-2003 Lars Knoll (knoll@kde.org)
  *               1999 Waldo Bastian (bastian@kde.org)
  *               2001 Andreas Schlapbach (schlpbch@iam.unibe.ch)
  *               2001-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 379 matching lines @@
     if (m_match == Tag)
         printf("%*stagQName().localName: %s\n", indent, "", tagQName().localName().ascii().data());
     printf("%*sisAttributeSelector(): %d\n", indent, "", isAttributeSelector());
     if (isAttributeSelector())
         printf("%*sattribute(): %s\n", indent, "", attribute().localName().ascii().data());
     printf("%*sargument(): %s\n", indent, "", argument().ascii().data());
     printf("%*sspecificity(): %u\n", indent, "", specificity());
     if (tagHistory()) {
         printf("\n%*s--> (relation == %d)\n", indent, "", relation());
         tagHistory()->show(indent + 2);
+    } else {
+        printf("\n%*s--> (relation == %d)\n", indent, "", relation());
     }
 }
 
 void CSSSelector::show() const
 {
     printf("\n******* CSSSelector::show(\"%s\") *******\n", selectorText().ascii().data());
     show(2);
     printf("******* end *******\n");
 }
 #endif
@@ skipping 466 matching lines @@
             return false;
         return (count - m_b) % m_a == 0;
     } else {
         if (count > m_b)
             return false;
         return (m_b - count) % (-m_a) == 0;
     }
 }
 
 } // namespace WebCore