// Null byte injection (the string contains literal null byte)
        assertEquals("fess.log\0.txt", AdminLogAction.sanitizeFilename("fess.log\0.txt"));
    }

    @Test
    public void test_security_unicodeCharacters() {
        // Full-width dots and other Unicode characters
        assertEquals("\uff0e\uff0e/test.log", AdminLogAction.sanitizeFilename("\uff0e\uff0e/test.log"));
    }