[#2570] Fix IGroupForm check_data_dict not being called

Make group_create() and group_update() call the check_data_dict()
methods of IGroupForm plugins, like package_create() and
package_update() do with IDatasetForm plugins.

ckan/logic/action/create.py

@@ -512,6 +512,14 @@ def group_create(context, data_dict):
     except AttributeError:
         schema = group_plugin.form_to_db_schema()
 
+    if 'api_version' not in context:
+        # old plugins do not support passing the schema so we need
+        # to ensure they still work
+        try:
+            group_plugin.check_data_dict(data_dict, schema)
+        except TypeError:
+            group_plugin.check_data_dict(data_dict)
+
     data, errors = _validate(data_dict, schema, context)
     log.debug('group_create validate_errs=%r user=%s group=%s data_dict=%r',
               errors, context.get('user'), data_dict.get('name'), data_dict)

ckan/logic/action/update.py

@@ -415,6 +415,14 @@ def group_update(context, data_dict):
 
     _check_access('group_update', context, data_dict)
 
+    if 'api_version' not in context:
+        # old plugins do not support passing the schema so we need
+        # to ensure they still work
+        try:
+            group_plugin.check_data_dict(data_dict, schema)
+        except TypeError:
+            group_plugin.check_data_dict(data_dict)
+
     data, errors = _validate(data_dict, schema, context)
     log.debug('group_update validate_errs=%r user=%s group=%s data_dict=%r',
               errors, context.get('user'),