fix empy serach range query

ckanext/odsh/plugin.py

@@ -396,6 +396,8 @@ class OdshPlugin(plugins.SingletonPlugin, DefaultTranslation, DefaultDatasetForm
         except ValueError:
             return search_params
 
+        empty_range = start_date and end_date and start_date > end_date
+
         if not start_date and not end_date:
             return search_params
 
@@ -416,7 +418,7 @@ class OdshPlugin(plugins.SingletonPlugin, DefaultTranslation, DefaultDatasetForm
             start_date=start_date, end_date=end_date)
 
         enclosing_query = ''
-        if do_enclosing_query:
+        if do_enclosing_query and not empty_range:
             enclosing_query_start = 'extras_temporal_start:[* TO {start_date}]'.format(
                 start_date=start_date)
 

ckanext/odsh/tests/test_search.py

@@ -52,6 +52,17 @@ class TestSearch(helpers.FunctionalTestBase):
         # assert
         assert dataset['name'] in response
 
+    @odsh_test()
+    def test_query_with_end_before_start_finds_no_dataset(self):
+        # arrange
+        datasetA = self._create_dataset('dataseta', '1960-01-01', '1960-12-31')
+
+        # act
+        response = self._perform_date_search('1960-12-30', '1960-02-01')
+
+        # assert
+        self._assert_no_results(response)
+
     @odsh_test()
     def test_query_with_wrong_dates_shows_error(self):
         # arrange