Fix list loading for non-object lists

confiddler/core.py

@@ -246,19 +246,23 @@ def set_defaults_and_validate(validator, properties, instance, schema):
             yield error
 
     def fill_in_default_array_items(validator, items_schema, instance, schema):
-        new_items = []
-        for item in instance:
-            if "default" in items_schema:
-                default = copy.deepcopy(items_schema["default"])
-                if isinstance(default, dict):
+        if "default" in items_schema and isinstance(items_schema["default"], Mapping):
+            new_items = []
+            for item in instance:
+                if not isinstance(item, Mapping):
+                    new_items.append(item)
+                else:
+                    default = copy.deepcopy(items_schema["default"])
                     default = _Dict(default)
                     if item == {}:
+                        # FIXME: Instead of a simple bool, it would be better to specify
+                        #        WHICH properties in this dict were copied from the default value.
                         default.from_default = True
                     default.update(item)
                     new_items.append(default)
 
-        instance.clear()
-        instance.extend(new_items)
+            instance.clear()
+            instance.extend(new_items)
 
         # Descend into array list
         for error in validate_items(validator, items_schema, instance, schema):

confiddler/tests/test_core.py

@@ -119,6 +119,28 @@ def test_missing_required_property_no_default():
         load_config(f, schema)
 
 
+def test_load_list():
+    """
+    Make sure lists can be loaded properly
+    (e.g. that it isn't overwritten with the default, etc.)
+    """
+    schema = copy.deepcopy(TEST_SCHEMA)
+    schema['properties']['mylist'] = {
+        'type': 'array',
+        'items': {'type': 'string'},
+        'default': []
+    }
+
+    data = {'mylist': ['a', 'b', 'c']}
+
+    f = StringIO()
+    yaml.dump(data, f)
+    f.seek(0)
+
+    cfg = load_config(f, schema)
+    assert cfg['mylist'] == list('abc')
+
+
 def test_emit_defaults():
     schema = copy.deepcopy(TEST_SCHEMA)
     defaults = emit_defaults(schema)