[BUGFIX] Fix parseUserFuncArguments to respect 0 as argument

"0" must be an valid "last argument" value in the parseUserFuncArguments
method.

The implementation of the argument iteration must strictly check if
the arguments string is empty.

Change-Id: I8cee20a48030ea9163f55723d9027f39c43e5e1c
Resolves: #68132
Related: #61256
Releases: master, 6.2
Reviewed-on: http://review.typo3.org/41218


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benjamin Mack <benni@typo3.org>
Tested-by: Benjamin Mack <benni@typo3.org>

typo3/sysext/core/Classes/Configuration/TypoScript/ConditionMatching/AbstractConditionMatcher.php

@@ -469,7 +469,7 @@ abstract class AbstractConditionMatcher {
 	protected function parseUserFuncArguments($arguments) {
 		$result = array();
 		$arguments = trim($arguments);
-		while ($arguments) {
+		while ($arguments !== '') {
 			if ($arguments[0] === ',') {
 				$result[] = '';
 				$arguments = substr($arguments, 1);