None and [] are both possible

config.py

@@ -17,7 +17,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #
 # The original `Config` design model is unproudly borrowed from 
-# the rough gus of pypy: pypy: http://codespeak.net/svn/pypy/dist/pypy/config/
+# the rough pypy's guys: http://codespeak.net/svn/pypy/dist/pypy/config/
 # the whole pypy projet is under MIT licence
 # ____________________________________________________________
 from error import (HiddenOptionError, ConfigError, NotFoundError, 
@@ -154,14 +154,7 @@ class Config(object):
         if type(getattr(self._cfgimpl_descr, name)) != SymLinkOption:
             self._validate(name, getattr(self._cfgimpl_descr, name))
         self.setoption(name, value, self._cfgimpl_owner)
-
-#    def __setitem__(self, key, value):
-#        print "entering __setitem__"
-#        if '.' in name:
-#            homeconfig, name = self._cfgimpl_get_home_by_path(name)
-#            return "hello" #setattr(homeconfig, name, value)
-#        return "titi"
-                 
+        
     def _validate(self, name, opt_or_descr):
         if not type(opt_or_descr) == OptionDescription:
             apply_requires(opt_or_descr, self) 
@@ -325,11 +318,11 @@ class Config(object):
             if who == 'auto':
                 if not child._is_hidden():
                     child.hide()
-            if value is None and who != 'default':
-                if child.is_multi():
-                     child.setowner(self, ['default' for i in range(len(child.getdefault()))])
-                else:
-                    child.setowner(self, 'default')
+            if (value is None and who != 'default' and not child.is_multi()):
+                child.setowner(self, 'default')
+                self._cfgimpl_values[name] = child.getdefault()
+            elif (value == [] and who != 'default' and child.is_multi()):
+                child.setowner(self, ['default' for i in range(len(child.getdefault()))])
                 self._cfgimpl_values[name] = child.getdefault()
             else:         
                 child.setowner(self, newowner)

option.py

@@ -17,7 +17,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #
 # The original `Config` design model is unproudly borrowed from 
-# the rough gus of pypy: pypy: http://codespeak.net/svn/pypy/dist/pypy/config/
+# the rough pypy's guys: http://codespeak.net/svn/pypy/dist/pypy/config/
 # the whole pypy projet is under MIT licence
 # ____________________________________________________________
 from autolib import special_owners
@@ -80,7 +80,6 @@ class Option(HiddenBaseType, DisabledBaseType, ModeBaseType):
                 if val != None:
                     # None allows the reset of the value
                     return self._validate(val)
-
         return True
 
     def getdefault(self):

test/test_option_setting.py

@@ -25,7 +25,6 @@ def make_description():
                                            wantframework_option,
                                            intoption, boolop])
     return descr
-
 #____________________________________________________________
 # change with __setattr__
 def test_attribute_access():
@@ -36,7 +35,13 @@ def test_attribute_access():
     # let's try to change it again
     config.string = "foo"
     assert config.string == "foo"
-#    raises(ConflictConfigError, 'config.string = "bar"')
+
+def test_setitem():
+    s = StrOption("string", "", default=["string"], multi=True)
+    descr = OptionDescription("options", "", [s])
+    config = Config(descr)
+    config.string = ["foo", "eggs"]
+    
 
 def test_reset():
     "if value is None, resets to default owner"
@@ -50,6 +55,20 @@ def test_reset():
     assert config.string == 'string'
     assert config._cfgimpl_value_owners['string'] == 'default'
 
+def test_reset_with_multi():
+    s = StrOption("string", "", default=["string"], default_multi="string" , multi=True)
+    descr = OptionDescription("options", "", [s])
+    config = Config(descr)
+    config.string = []
+    assert config.string == ["string"]
+    assert config._cfgimpl_value_owners['string'] == ['default']
+    config.string = ["eggs", "spam", "foo"]
+    assert config._cfgimpl_value_owners['string'] == ['user', 'user', 'user']
+    config.string = []
+    assert config.string == ["string"]
+    assert config._cfgimpl_value_owners['string'] == ['default']
+    raises(ConfigError, "config.string = None")
+    
 def test_idontexist():
     descr = make_description()
     cfg = Config(descr)