fix issue 9601: ftplib now provides a workaround for invalid response code returned on MKD and PWD by non-compliant FTPserver implementations such as ISS shipped with Windows server 2003
diff --git a/Lib/ftplib.py b/Lib/ftplib.py
index 8a097c0..ef69ca6 100644
--- a/Lib/ftplib.py
+++ b/Lib/ftplib.py
@@ -565,7 +565,11 @@
 
     def mkd(self, dirname):
         '''Make a directory, return its full pathname.'''
-        resp = self.sendcmd('MKD ' + dirname)
+        resp = self.voidcmd('MKD ' + dirname)
+        # fix around non-compliant implementations such as IIS shipped
+        # with Windows server 2003
+        if not resp.startswith('257'):
+            return ''
         return parse257(resp)
 
     def rmd(self, dirname):
@@ -574,7 +578,11 @@
 
     def pwd(self):
         '''Return current working directory.'''
-        resp = self.sendcmd('PWD')
+        resp = self.voidcmd('PWD')
+        # fix around non-compliant implementations such as IIS shipped
+        # with Windows server 2003
+        if not resp.startswith('257'):
+            return ''
         return parse257(resp)
 
     def quit(self):