Backported the url changes from 2.0.

url function now behaves properly while given an empty dict.

CHANGES.txt

@@ -4,8 +4,7 @@ Changes
 1.13.5 (unreleased)
 -------------------
 
-- Nothing changed yet.
-
+- Fix the url() function to behave properly while passed an empty data dict.
 
 1.13.4 (2010-06-01)
 -------------------

src/grokcore/view/ftests/url/url_function.py

@@ -78,6 +78,14 @@
   >>> url(request, herd, None, data=dict(name="Peter"))
   'http://127.0.0.1/herd?name=Peter'
 
+Providing an empty dict gives the same result than giving None:
+
+  >>> url(request, herd, data={})
+  'http://127.0.0.1/herd'
+
+  >>> url(request, herd, data=None)
+  'http://127.0.0.1/herd'
+
 Since order in dictionairies is arbitrary we'll test the presence of multiple
 keywords by using find()
 

src/grokcore/view/util.py

@@ -18,23 +18,24 @@
 from zope.traversing.browser.interfaces import IAbsoluteURL
 from zope.traversing.browser.absoluteurl import _safe as SAFE_URL_CHARACTERS
 
+
 def url(request, obj, name=None, data=None):
     url = getMultiAdapter((obj, request), IAbsoluteURL)()
     if name is not None:
         url += '/' + urllib.quote(name.encode('utf-8'), SAFE_URL_CHARACTERS)
-        
-    if data is None:
+
+    if not data:
         return url
-    
+
     if not isinstance(data, dict):
         raise TypeError('url() data argument must be a dict.')
-        
+
     for k,v in data.items():
         if isinstance(v, unicode):
             data[k] = v.encode('utf-8')
         if isinstance(v, (list, set, tuple)):
             data[k] = [
                 isinstance(item, unicode) and item.encode('utf-8')
                 or item for item in v]
-            
+
     return url + '?' + urllib.urlencode(data, doseq=True)