Problem building XWiki Platform - Core - Core with Polish locale set (UtilTest.testConvertToAlphaNumeric())

There is a funny lil problem running

testConvertToAlphaNumeric()

in class

core\xwiki-core\src\test\java\com\xpn\xwiki\util\UtilTest.java 

assertEquals("e", Util.convertToAlphaNumeric("e$%?#^()"));

"?" (hex 0xA3) is a Polish letter (it's even the first letter of my name ) that is converted to "L" which in turns produces "eL" --> test fails --> build fails