GH-96172 unicodedata: fix wrong default for east_asian_width

also return the correct width for unassigned but reserved characters
according to EastAsianWidth.txt

Author: cfbolz

Lib/test/test_unicodedata.py

@@ -220,6 +220,18 @@ def test_east_asian_width(self):
         self.assertEqual(eaw('\u2010'), 'A')
         self.assertEqual(eaw('\U00020000'), 'W')
 
+    def test_east_asian_width_unassigned(self):
+        eaw = self.db.east_asian_width
+        # unassigned
+        for char in '\u0530\u0ece\u10c6\u20fc\uaaca\U000107bd\U000115f2':
+            self.assertEqual(eaw(char), 'N')
+            self.assertIs(self.db.name(char, None), None)
+
+        # unassigned but reserved
+        for char in '\uFA6E\uFADA\U0002A6E0\U0002FA20\U0003134B\U0003FFFD':
+            self.assertEqual(eaw(char), 'W')
+            self.assertIs(self.db.name(char, None), None)
+
     def test_east_asian_width_9_0_changes(self):
         self.assertEqual(self.db.ucd_3_2_0.east_asian_width('\u231a'), 'N')
         self.assertEqual(self.db.east_asian_width('\u231a'), 'W')