[#691] Remove fq on legacy search API and force public datasets

Even if it is a backwards breaking change we sholdn't be allowing the fq
parameter to be set through the API as it can lead to privacy issues. We
will also enforce that all datasets available through the API are public
(as the v3 API does)

ckan/controllers/api.py

@@ -532,6 +532,12 @@ def search(self, ver=None, register=None):
                         params = search.\
                             convert_legacy_parameters_to_solr(params)
                     query = search.query_for(model.Package)
+
+                    # Remove any existing fq param and set the capacity to
+                    # public
+                    if 'fq' in params:
+                        del params['fq']
+                    params['fq'] = '+capacity:public'
                     results = query.run(params)
                 return self._finish_ok(results)
             except search.SearchError, e: