Sjoerd Mullender writes:

Fixed a TypeError: not enough arguments; expected 4, got 3.
When authentication is needed, the default http_error_401 method calls
retry_http_basic_auth.  The default version of that method expected a
data argument which wasn't provided, so now we provide the argument if
it was given and we also made the data argument optional.

Also changed other calls where data was optional to not pass data if
it was not passed to the calling method (in line with other similar
occurances).
diff --git a/Lib/urllib.py b/Lib/urllib.py
index ffbab22..dbe3bee 100644
--- a/Lib/urllib.py
+++ b/Lib/urllib.py
@@ -499,7 +499,10 @@
         fp.close()
         # In case the server sent a relative URL, join with original:
         newurl = basejoin("http:" + url, newurl)
-        return self.open(newurl, data)
+        if data is None:
+            return self.open(newurl)
+        else:
+            return self.open(newurl, data)
 
     # Error 301 -- also relocated (permanently)
     http_error_301 = http_error_302
@@ -517,9 +520,12 @@
                 scheme, realm = match.groups()
                 if string.lower(scheme) == 'basic':
                    name = 'retry_' + self.type + '_basic_auth'
-                   return getattr(self,name)(url, realm)
+                   if data is None:
+                       return getattr(self,name)(url, realm)
+                   else:
+                       return getattr(self,name)(url, realm, data)
 
-    def retry_http_basic_auth(self, url, realm, data):
+    def retry_http_basic_auth(self, url, realm, data=None):
         host, selector = splithost(url)
         i = string.find(host, '@') + 1
         host = host[i:]
@@ -527,9 +533,12 @@
         if not (user or passwd): return None
         host = user + ':' + passwd + '@' + host
         newurl = 'http://' + host + selector
-        return self.open(newurl, data)
+        if data is None:
+            return self.open(newurl)
+        else:
+            return self.open(newurl, data)
    
-    def retry_https_basic_auth(self, url, realm):
+    def retry_https_basic_auth(self, url, realm, data=None):
             host, selector = splithost(url)
             i = string.find(host, '@') + 1
             host = host[i:]