[#1841] define NameConflict error instead of using Excepion itself

ckan/logic/__init__.py

@@ -16,6 +16,10 @@
 _validate = df.validate
 
 
+class NameConflict(Exception):
+    pass
+
+
 class AttributeDict(dict):
     def __getattr__(self, name):
         try:
@@ -377,7 +381,7 @@ def get_action(action):
     for plugin in p.PluginImplementations(p.IActions):
         for name, auth_function in plugin.get_actions().items():
             if name in resolved_action_plugins:
-                raise Exception(
+                raise NameConflict(
                     'The action %r is already implemented in %r' % (
                         name,
                         resolved_action_plugins[name]
@@ -628,7 +632,7 @@ def get_validator(validator):
         for plugin in p.PluginImplementations(p.IValidators):
             for name, validator in plugin.get_validators().items():
                 if name in _validators_cache:
-                    raise Exception(
+                    raise NameConflict(
                         'The validator %r is already defined' % (name,)
                     )
                 log.debug('Validator function {0} from plugin {1} was inserted'.format(name, plugin.name))
@@ -675,7 +679,7 @@ def get_converter(converter):
         for plugin in p.PluginImplementations(p.IConverters):
             for name, converter in plugin.get_converters().items():
                 if name in _converters_cache:
-                    raise Exception(
+                    raise NameConflict(
                         'The converter %r is already defined' % (name,)
                     )
                 log.debug('Converter function {0} from plugin {1} was inserted'.format(name, plugin.name))