None and [] are both possible

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)