Fix debugging with Python2 on Windows with non-English locale (PY-17409)

Standart normcase() function doesn't change case for non-English letters, so we should do it manually.

python/helpers/pydev/pydevd_file_utils.py

@@ -42,6 +42,7 @@
 
 
 from pydevd_constants import *  #@UnusedWildImport
+from _pydev_filesystem_encoding import getfilesystemencoding
 import os.path
 import sys
 import traceback
@@ -72,6 +73,15 @@ PATHS_FROM_ECLIPSE_TO_PYTHON = []
 
 normcase = os_normcase # May be rebound on set_ide_os
 
+
+def norm_case(filename):
+    filename = os_normcase(filename)
+    if IS_PY3K:
+        return filename
+    enc = getfilesystemencoding()
+    return filename.decode(enc).lower().encode(enc)
+
+
 def set_ide_os(os):
     '''
     We need to set the IDE os because the host where the code is running may be
@@ -82,7 +92,7 @@ def set_ide_os(os):
     if os == 'UNIX':
         normcase = lambda f:f #Change to no-op if the client side is on unix/mac.
     else:
-        normcase = os_normcase
+        normcase = norm_case
 
     # After setting the ide OS, apply the normcase to the existing paths.