Fix potential bug in requestmethod where you cannot specify None for a keyword...

Fix potential bug in requestmethod where you cannot specify None for a keyword argument where None is not the default

lib/python/AccessControl/requestmethod.py

@@ -15,14 +15,16 @@ import inspect
 from zExceptions import Forbidden
 from zope.publisher.interfaces.browser import IBrowserRequest
 
+_default = []
+
 def _buildFacade(spec, docstring):
     """Build a facade function, matching the decorated method in signature.
     
-    Note that defaults are replaced by None, and _curried will reconstruct
+    Note that defaults are replaced by _default, and _curried will reconstruct
     these to preserve mutable defaults.
     
     """
-    args = inspect.formatargspec(formatvalue=lambda v: '=None', *spec)
+    args = inspect.formatargspec(formatvalue=lambda v: '=_default', *spec)
     callargs = inspect.formatargspec(formatvalue=lambda v: '', *spec)
     return 'def _facade%s:\n    """%s"""\n    return _curried%s' % (
         args, docstring, callargs)
@@ -60,7 +62,7 @@ def requestmethod(*methods):
             if defaults is not None:
                 args, kwparams = args[:arglen], args[arglen:]
                 for positional, (key, default) in zip(kwparams, defaults):
-                    if positional is None:
+                    if positional is _default:
                         kw[key] = default
                     else:
                         kw[key] = positional
@@ -68,7 +70,7 @@ def requestmethod(*methods):
             return callable(*args, **kw)
         
         # Build a facade, with a reference to our locally-scoped _curried
-        facade_globs = dict(_curried=_curried)
+        facade_globs = dict(_curried=_curried, _default=_default)
         exec _buildFacade(spec, callable.__doc__) in facade_globs
         return facade_globs['_facade']
     

lib/python/AccessControl/requestmethod.txt

@@ -57,12 +57,12 @@ original closely, and keyword parameter defaults must be preserved::
   >>> import inspect
   >>> mutabledefault = dict()
   >>> @requestmethod('POST')
-  ... def foo(bar, baz=mutabledefault, REQUEST=None, **kw):
-  ...     return bar, baz is mutabledefault, REQUEST
+  ... def foo(bar, baz=mutabledefault, egg=mutabledefault, REQUEST=None, **kw):
+  ...     return bar, baz is mutabledefault, egg is None, REQUEST
   >>> inspect.getargspec(foo)[:3]
-  (['bar', 'baz', 'REQUEST'], None, 'kw')
-  >>> foo('spam')
-  ('spam', True, None)
+  (['bar', 'baz', 'egg', 'REQUEST'], None, 'kw')
+  >>> foo('spam', egg=None)
+  ('spam', True, True, None)
   
 The requestmethod decorator factory can be used for any request method, simply
 pass in the desired request method::