Bug fix for relative directory removal

UnitTest-e8af5d1.php

<?php

$examples = array(
	  '../'           => ''
	, '/../'          => ''
	, 'abc/../'       => 'abc'
	, '../def'        => 'def'
	, '/../def'       => 'def'
	, 'abc/../../def' => 'abc/def'
	, 'abc../'        => 'abc..'
	, 'abc/def../'    => 'abc/def..'
	, 'abc/def../ghi' => 'abc/def../ghi'
	, 'abc/def../ghi' => 'abc/def../ghi'

	, 'abc//def'      => 'abc/def'
	, 'abc///def'     => 'abc/def'
	, 'abc////def'    => 'abc/def'

	, '0/abc'         => '0/abc'
	, '00/abc'        => '00/abc'
	, 'abc/0'         => 'abc/0'
	, 'abc/00'        => 'abc/00'
	, 'abc/0/def'     => 'abc/0/def'
	, 'abc/00/def'    => 'abc/00/def'
);

foreach($examples as $uri=>$expectedResult)
{
	// $testResult = str_replace(array('//', '../'), '/', trim($uri, '/')) //fail
	// $testResult = preg_replace('#(^|/)\.\./|/+#', '/', $uri); //fail
	// $testResult = remove_relative_explode($uri);
	$testResult = remove_relative($uri);

	//echo $testResult;
	// remove leading and trailing slash if any, expectedResult does not care
	echo trim($testResult, '/') == $expectedResult ? '.' : 'F';
	echo " " . $uri . "\n";
}

function remove_relative($uri)
{
	$uris = array();
	$tok = strtok($uri, '/');
	while ($tok !== FALSE)
	{
		if (( ! empty($tok) OR $tok === '0') && $tok !== '..')
		{
			$uris[] = $tok;
		}
		$tok = strtok('/');
	}
	return implode('/', $uris);
}

function remove_relative_explode($url)
{
	$uris = array();
	$toks = explode('/', $url);
	foreach ($toks as $tok)
		($tok != '..' && ! empty($tok) || $tok === '0') && $uris[] = $tok;
	return implode('/', $uris);
}