Index: Objects/unicodeobject.c
===================================================================
--- Objects/unicodeobject.c	(revision 58574)
+++ Objects/unicodeobject.c	(working copy)
@@ -1056,21 +1056,39 @@
 {
     PyObject *buffer = NULL, *unicode;
     Py_buffer info;
+    /* strlen("latin-1") + 1 safety + \0 */
+    char lower[9], *l = lower, *e;
 
     if (encoding == NULL)
-	encoding = PyUnicode_GetDefaultEncoding();
+        encoding = PyUnicode_GetDefaultEncoding();
 
+    /* Convert encoding to lower case in order to catch e.g. UTF-8 */
+    e = (char*)encoding;
+    while (*e && (l - lower) < 8) {
+        if (isupper(Py_CHARMASK(*e))) {
+            *l++ = tolower(Py_CHARMASK(*e++));
+        }
+        else {
+            *l++ = *e++;
+        }
+    }
+    *l = '\0';
+
     /* Shortcuts for common default encodings */
-    if (strcmp(encoding, "utf-8") == 0)
+    if (strcmp(lower, "utf-8") == 0)
         return PyUnicode_DecodeUTF8(s, size, errors);
-    else if (strcmp(encoding, "latin-1") == 0)
+    else if (strcmp(lower, "latin-1") == 0)
         return PyUnicode_DecodeLatin1(s, size, errors);
 #if defined(MS_WINDOWS) && defined(HAVE_USABLE_WCHAR_T)
-    else if (strcmp(encoding, "mbcs") == 0)
+    else if (strcmp(lower, "mbcs") == 0)
         return PyUnicode_DecodeMBCS(s, size, errors);
 #endif
-    else if (strcmp(encoding, "ascii") == 0)
+    else if (strcmp(lower, "ascii") == 0)
         return PyUnicode_DecodeASCII(s, size, errors);
+    else if (strcmp(lower, "utf-16") == 0)
+        return PyUnicode_DecodeUTF16(s, size, errors, 0);
+    else if (strcmp(lower, "utf-32") == 0)
+        return PyUnicode_DecodeUTF32(s, size, errors, 0);
 
     /* Decode via the codec registry */
     buffer = NULL;
Index: Lib/test/regrtest.py
===================================================================
--- Lib/test/regrtest.py	(revision 58574)
+++ Lib/test/regrtest.py	(working copy)
@@ -1119,6 +1119,15 @@
             if not os.path.supports_unicode_filenames:
                 self.expected.add('test_pep277')
 
+            # doctest, profile and cProfile tests fail when the codec for the fs
+            # encoding isn't built in because PyUnicode_Decode() adds two calls
+            # into Python.
+            encs = ("utf-8", "latin-1", "ascii", "mbcs", "utf-16", "utf-32")
+            if sys.getfilesystemencoding().lower() not in encs:
+                self.expected.add('test_profile')
+                self.expected.add('test_cProfile')
+                self.expected.add('test_doctest')
+
             try:
                 from test import test_socket_ssl
             except ImportError: