diff -r aa73e60f65e9 Lib/test/test_codecs.py
--- a/Lib/test/test_codecs.py	Fri Sep 21 17:26:35 2012 +0300
+++ b/Lib/test/test_codecs.py	Fri Sep 21 23:08:15 2012 +0300
@@ -1546,6 +1546,10 @@
             ("abc", 3)
         )
 
+        self.assertRaises(UnicodeDecodeError,
+            codecs.charmap_decode, b"\x00\x01\x02", "strict", "ab"
+        )
+
         self.assertEqual(
             codecs.charmap_decode(b"\x00\x01\x02", "replace", "ab"),
             ("ab\ufffd", 3)
@@ -1572,6 +1576,107 @@
             ("", len(allbytes))
         )
 
+    def test_decode_with_int2str_map(self):
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "strict",
+                                  {0: 'a', 1: 'b', 2: 'c'}),
+            ("abc", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "strict",
+                                  {0: 'Aa', 1: 'Bb', 2: 'Cc'}),
+            ("AaBbCc", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "strict",
+                                  {0: '\U0010FFFF', 1: 'b', 2: 'c'}),
+            ("\U0010FFFFbc", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "strict",
+                                  {0: 'a', 1: 'b', 2: ''}),
+            ("ab", 3)
+        )
+
+        self.assertRaises(UnicodeDecodeError,
+            codecs.charmap_decode, b"\x00\x01\x02", "strict",
+                                   {0: 'a', 1: 'b'}
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "replace",
+                                  {0: 'a', 1: 'b'}),
+            ("ab\ufffd", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "replace",
+                                  {0: 'a', 1: 'b', 2: None}),
+            ("ab\ufffd", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "ignore",
+                                  {0: 'a', 1: 'b'}),
+            ("ab", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "ignore",
+                                  {0: 'a', 1: 'b', 2: None}),
+            ("ab", 3)
+        )
+
+        allbytes = bytes(range(256))
+        self.assertEqual(
+            codecs.charmap_decode(allbytes, "ignore", {}),
+            ("", len(allbytes))
+        )
+
+    def test_decode_with_int2int_map(self):
+        a = ord('a')
+        b = ord('b')
+        c = ord('c')
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "strict",
+                                  {0: a, 1: b, 2: c}),
+            ("abc", 3)
+        )
+
+        # Issue #15379
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "strict",
+                                  {0: 0x10FFFF, 1: b, 2: c}),
+            ("\U0010FFFFbc", 3)
+        )
+
+        self.assertRaises(TypeError,
+            codecs.charmap_decode, b"\x00\x01\x02", "strict",
+                                   {0: 0x110000, 1: b, 2: c}
+        )
+
+        self.assertRaises(UnicodeDecodeError,
+            codecs.charmap_decode, b"\x00\x01\x02", "strict",
+                                   {0: a, 1: b},
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "replace",
+                                  {0: a, 1: b}),
+            ("ab\ufffd", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "ignore",
+                                  {0: a, 1: b}),
+            ("ab", 3)
+        )
+
+
 class WithStmtTest(unittest.TestCase):
     def test_encodedfile(self):
         f = io.BytesIO(b"\xc3\xbc")
diff -r aa73e60f65e9 Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Fri Sep 21 17:26:35 2012 +0300
+++ b/Objects/unicodeobject.c	Fri Sep 21 23:08:15 2012 +0300
@@ -5250,12 +5250,36 @@
             /* Apply mapping */
             if (PyLong_Check(x)) {
                 long value = PyLong_AS_LONG(x);
-                if (value < 0 || value > 65535) {
+                if (value < 0 || value > 0x10FFFF) {
                     PyErr_SetString(PyExc_TypeError,
-                                    "character mapping must be in range(65536)");
+                                    "character mapping must be in range(0x110000)");
                     Py_DECREF(x);
                     goto onError;
                 }
+
+#ifndef Py_UNICODE_WIDE
+                if (value > 0xFFFF) {
+                    /* see the code for 1-n mapping below */
+                    if (extrachars < 2) {
+                        /* resize first */
+                        Py_ssize_t oldpos = p - PyUnicode_AS_UNICODE(v);
+                        Py_ssize_t needed = 10 - extrachars;
+                        extrachars += needed;
+                        /* XXX overflow detection missing */
+                        if (_PyUnicode_Resize(&v,
+                                              PyUnicode_GET_SIZE(v) + needed) < 0) {
+                            Py_DECREF(x);
+                            goto onError;
+                        }
+                        p = PyUnicode_AS_UNICODE(v) + oldpos;
+                    }
+                    value -= 0x10000;
+                    *p++ = 0xD800 | (value >> 10);
+                    *p++ = 0xDC00 | (value & 0x3FF);
+                    extrachars -= 2;
+                }
+                else
+#endif
                 *p++ = (Py_UNICODE)value;
             }
             else if (x == Py_None) {