Fix bug #67644 - Memory corruption & crash during ob_start function callback
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  Fix bug #67644 - Memory corruption & crash during ob_start function callback
Merge branch 'PHP-5.5' into PHP-5.6

* PHP-5.5:
  Fix bug #67644 - Memory corruption & crash during ob_start function callback
Merge branch 'PHP-5.6'

* PHP-5.6:
  Fix bug #67644 - Memory corruption & crash during ob_start function callback