Patches by Michael Reilly to correctly deal with ftp URLs of the form

gvanrossum · gvanrossum · commit 1ebcf6aabb35 · 1999-08-18T21:51:10.000Z
ftp://user@host//root/path: the double slash in the pathname means to
go to the root directory even if the initial directory isn't the root.
diff --git a/Lib/ftplib.py b/Lib/ftplib.py
@@ -437,6 +437,8 @@ def cwd(self, dirname):
 			except error_perm, msg:
 				if msg[:3] != '500':
 					raise error_perm, msg
+		elif dirname == '':
+			dirname = '.'  # does nothing, but could return error
 		cmd = 'CWD ' + dirname
 		return self.voidcmd(cmd)
 
