Calculate buffer size once

appdirs.py

@@ -483,12 +483,13 @@ def _get_win_folder_with_jna(csidl_name):
     import array
     from com.sun import jna
     from com.sun.jna.platform import win32
-
-    buf = array.zeros('c', win32.WinDef.MAX_PATH * 2)
+
+    buf_size = win32.WinDef.MAX_PATH * 2
+    buf = array.zeros('c', buf_size)
     shell = win32.Shell32.INSTANCE
     shell.SHGetFolderPath(None, getattr(win32.ShlObj, csidl_name), None, win32.ShlObj.SHGFP_TYPE_CURRENT, buf)
     dir = jna.Native.toString(buf.tostring()).rstrip(u"\0")
-    
+
     # Downgrade to short path name if have highbit chars. See
     # <http://bugs.activestate.com/show_bug.cgi?id=85099>.
     has_high_char = False
@@ -497,13 +498,13 @@ def _get_win_folder_with_jna(csidl_name):
             has_high_char = True
             break
     if has_high_char:
-        buf = array.zeros('c', win32.WinDef.MAX_PATH * 2)
+        buf = array.zeros('c', buf_size)
         kernel = win32.Kernel32.INSTANCE
-        if kernal.GetShortPathName(dir, buf, win32.WinDef.MAX_PATH * 2):
+        if kernal.GetShortPathName(dir, buf, buf_size):
             dir = jna.Native.toString(buf.tostring()).rstrip(u"\0")
-    
+
     return dir
-    
+
 if system == "win32":
     try:
         import win32com.shell