Index: cookielib.py
===================================================================
--- cookielib.py	(revision 74229)
+++ cookielib.py	(working copy)
@@ -1482,7 +1482,8 @@
         if domain is Absent:
             req_host, erhn = eff_request_host(request)
             domain = erhn
-        elif not domain.startswith("."):
+        # Dot on all domains is RFC required and helps self.clear() 
+        if not domain.startswith("."):
             domain = "."+domain
 
         # set default port
@@ -1641,6 +1642,27 @@
         finally:
             self._cookies_lock.release()
 
+    def add_cookie(self, req, name, value, attr={}):
+        """Make a RFC2109 valid cookie and add it to the jar"""
+        self._cookies_lock.acquire()
+        try:
+            self._now = int(time.time())
+            attr_set = [(name,value) ]
+            attr_set.extend([(n,v) for n,v in attr.items()])
+        
+            cookies = self._cookies_from_attrs_set([attr_set], req)
+            self._process_rfc2109_cookies(cookies)
+           
+            if len(cookies) == 1: 
+                cookie = cookies[0]
+                try:
+                    self.clear(cookie.domain, cookie.path, cookie.name)
+                except KeyError:
+                    pass
+                self.set_cookie(cookies[0])
+        finally:
+            self._cookies_lock.release()
+        
     def clear(self, domain=None, path=None, name=None):
         """Clear some cookies.
 
Index: _LWPCookieJar.py
===================================================================
--- _LWPCookieJar.py	(revision 74229)
+++ _LWPCookieJar.py	(working copy)
@@ -42,7 +42,7 @@
     for k in keys:
         h.append((k, str(cookie._rest[k])))
 
-    h.append(("version", str(cookie.version)))
+    if cookie.version is not None: h.append(("version", str(cookie.version)))
 
     return join_header_words([h])