PHPT for bug 39863

Hi there, I've included my first ever phpt. Can someone please look over it and check that it meets your quality guidelines for a unit test? Once that's done, it probably should be included in the mainline test suite once someone from your security team says yes to bug 39863. The issue it tests is fairly serious - file_exists() amongst others can be fooled into saying a file exists, when in fact it doesn't - with a very simple and well known null byte injection. This test demonstrates the issue. I've tested the underlying test on CentOS / my hand rolled PHP 5.2.11 and MacOS X / Apple's PHP 5.3.1 and both fail this test. This issue should also be tested on non-Unix platforms, such as Windows. But I don't know how phpt's could test for say c:\boot.ini or another well known file. If I was fixing the bug, I'd canonicalize the value and positively validate the filename to only include acceptable characters for my OS's filenames. If the filename fails canonicalization or validation, returning false is more than acceptable for file_exists(), but other similarly afflicted file functions should be tested and their return result set according to the function's capabilities. thanks, Andrew