This fixes a missing .lower() on the encoding name, a wrong byte undecodable by UTF-8, a wrong variable name, hopefully some windows buildbot on 3.x and adds a proper skip. It might break other things though.

Lib/test/test_imp.py

@@ -85,13 +85,14 @@ class ImportTests(unittest.TestCase):
         # and issue never happens for dynamic modules.
         # But sources modified to follow generic way for processing pathes.
 
-        locale_encoding = locale.getpreferredencoding()
+        # the return encoding can be uppercase
+        locale_encoding = locale.getpreferredencoding().lower()
 
         # covers utf-8 and Windows ANSI code pages
         # one non-space symbol from every page
         # (http://en.wikipedia.org/wiki/Code_page)
         known_locales = {
-            'utf-8' : b'\xe4',
+            'utf-8' : b'\xc3\xa4',
             'cp1250' : b'\x8C',
             'cp1251' : b'\xc0',
             'cp1252' : b'\xc0',
@@ -104,10 +105,12 @@ class ImportTests(unittest.TestCase):
             }
 
         special_char = known_locales.get(locale_encoding)
-        if special_char:
-            encoded_char = special_char.decode(locale_encoding)
-            temp_mod_name = 'test_imp_helper_' + encoded_char
-            test_package_name = 'test_imp_helper_package_' + encoded_char
+        if not special_char:
+            self.skipTest("can't run this test with %s as preferred encoding"
+                          % locale_encoding)
+        decoded_char = special_char.decode(locale_encoding)
+        temp_mod_name = 'test_imp_helper_' + decoded_char
+        test_package_name = 'test_imp_helper_package_' + decoded_char
         init_file_name = os.path.join(test_package_name, '__init__.py')
         try:
             with open(temp_mod_name + '.py', 'w') as file: