Fix _all_docs call where keys is an empty list

Author: smithsz

src/cloudant/_common_util.py

@@ -237,11 +237,11 @@ def get_docs(r_session, url, encoder=None, headers=None, **params):
     """
     keys_list = params.pop('keys', None)
     keys = None
-    if keys_list:
+    if keys_list is not None:
         keys = json.dumps({'keys': keys_list}, cls=encoder)
     f_params = python_to_couch(params)
     resp = None
-    if keys:
+    if keys is not None:
         # If we're using POST we are sending JSON so add the header
         if headers is None:
             headers = {}

tests/unit/database_tests.py

@@ -432,6 +432,15 @@ def test_all_docs_post(self):
         keys_returned = [row['key'] for row in rows]
         self.assertTrue(all(x in keys_returned for x in keys_list))
 
+    def test_all_docs_post_empty_key_list(self):
+        """
+        Test the all_docs POST request functionality using empty keys param
+        """
+        self.populate_db_with_documents()
+        # Request all_docs using an empty key list
+        rows = self.db.all_docs(keys=[]).get('rows')
+        self.assertEqual(len(rows), 0)
+
     def test_all_docs_post_multiple_params(self):
         """
         Test the all_docs POST request functionality using keys and other params