- Fixed missing NULL check in SimpleXMLElement::xpath()
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  - Fixed missing NULL check in SimpleXMLElement::xpath()
Merge branch 'PHP-5.5' into PHP-5.6

* PHP-5.5:
  - Fixed missing NULL check in SimpleXMLElement::xpath()
Merge branch 'PHP-5.6'

* PHP-5.6:
  - Fixed missing NULL check in SimpleXMLElement::xpath()