Issue #17223: array module: Fix a crasher when converting an array containing
invalid characters (outside range [U+0000; U+10ffff]) to Unicode: repr(array),
str(array) and array.tounicode(). Patch written by Manuel Jacob.
diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index a532a9f..bfef4fa 100755
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -1069,6 +1069,12 @@
 
         self.assertRaises(TypeError, a.fromunicode)
 
+    def test_issue17223(self):
+        # this used to crash
+        a = array.array('u', b'\xff' * 4)
+        self.assertRaises(ValueError, a.tounicode)
+        self.assertRaises(ValueError, str, a)
+
 class NumberTest(BaseTest):
 
     def test_extslice(self):