Issue #7309: Unchecked pointer access when converting UnicodeEncodeError, UnicodeDecodeError, and UnicodeTranslateError to strings.
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index eff552f..8a0f30f 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -398,6 +398,43 @@
         self.assertTrue(unicode(Exception(u'a')))
         self.assertTrue(unicode(Exception(u'\xe1')))
 
+    def testUnicodeChangeAttributes(self):
+        # See issue 7309. This was a crasher.
+
+        u = UnicodeEncodeError('baz', u'xxxxx', 1, 5, 'foo')
+        self.assertEqual(str(u), "'baz' codec can't encode characters in position 1-4: foo")
+        u.end = 2
+        self.assertEqual(str(u), "'baz' codec can't encode character u'\\x78' in position 1: foo")
+        u.end = 5
+        u.reason = 0x345345345345345345
+        self.assertEqual(str(u), "'baz' codec can't encode characters in position 1-4: 965230951443685724997")
+        u.encoding = 4000
+        self.assertEqual(str(u), "'4000' codec can't encode characters in position 1-4: 965230951443685724997")
+        u.start = 1000
+        self.assertEqual(str(u), "'4000' codec can't encode characters in position 1000-4: 965230951443685724997")
+
+        u = UnicodeDecodeError('baz', 'xxxxx', 1, 5, 'foo')
+        self.assertEqual(str(u), "'baz' codec can't decode bytes in position 1-4: foo")
+        u.end = 2
+        self.assertEqual(str(u), "'baz' codec can't decode byte 0x78 in position 1: foo")
+        u.end = 5
+        u.reason = 0x345345345345345345
+        self.assertEqual(str(u), "'baz' codec can't decode bytes in position 1-4: 965230951443685724997")
+        u.encoding = 4000
+        self.assertEqual(str(u), "'4000' codec can't decode bytes in position 1-4: 965230951443685724997")
+        u.start = 1000
+        self.assertEqual(str(u), "'4000' codec can't decode bytes in position 1000-4: 965230951443685724997")
+
+        u = UnicodeTranslateError(u'xxxx', 1, 5, 'foo')
+        self.assertEqual(str(u), "can't translate characters in position 1-4: foo")
+        u.end = 2
+        self.assertEqual(str(u), "can't translate character u'\\x78' in position 1: foo")
+        u.end = 5
+        u.reason = 0x345345345345345345
+        self.assertEqual(str(u), "can't translate characters in position 1-4: 965230951443685724997")
+        u.start = 1000
+        self.assertEqual(str(u), "can't translate characters in position 1000-4: 965230951443685724997")
+
     def test_badisinstance(self):
         # Bug #2542: if issubclass(e, MyException) raises an exception,
         # it should be ignored