Fixed #19998 -- Fixed --ignorenonexistent support for XML based fixtures.

django/core/serializers/xml_serializer.py

@@ -155,6 +155,7 @@ class Deserializer(base.Deserializer):
         super(Deserializer, self).__init__(stream_or_string, **options)
         self.event_stream = pulldom.parse(self.stream, self._make_parser())
         self.db = options.pop('using', DEFAULT_DB_ALIAS)
+        self.ignore = options.pop('ignorenonexistent', False)
 
     def _make_parser(self):
         """Create a hardened XML parser (no custom/external entities)."""
@@ -188,6 +189,7 @@ class Deserializer(base.Deserializer):
         # {m2m_accessor_attribute : [list_of_related_objects]})
         m2m_data = {}
 
+        model_fields = Model._meta.get_all_field_names()
         # Deseralize each field.
         for field_node in node.getElementsByTagName("field"):
             # If the field is missing the name attribute, bail (are you
@@ -198,7 +200,9 @@ class Deserializer(base.Deserializer):
 
             # Get the field from the Model. This will raise a
             # FieldDoesNotExist if, well, the field doesn't exist, which will
-            # be propagated correctly.
+            # be propagated correctly unless ignorenonexistent=True is used.
+            if self.ignore and field_name not in model_fields:
+                continue
             field = Model._meta.get_field(field_name)
 
             # As is usually the case, relation fields get the special treatment.

tests/fixtures_regress/fixtures/sequence_extra_xml.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<django-objects version="1.0">
+    <object pk="1" model="fixtures_regress.animal">
+        <field type="CharField" name="name">Wolf</field>
+        <field type="CharField" name="extra_name">Super Wolf</field>
+        <field type="CharField" name="latin_name">Canis lupus</field>
+        <field type="IntegerField" name="count">3</field>
+        <field type="FloatField" name="weight">1.2</field>
+    </object>
+</django-objects>

tests/fixtures_regress/tests.py

@@ -87,6 +87,20 @@ class TestFixtures(TestCase):
         )
         self.assertEqual(Animal.specimens.all()[0].name, 'Lion')
 
+    def test_loaddata_not_found_fields_ignore_xml(self):
+        """
+        Test for ticket #19998 -- Ignore entries in the XML serialised data
+        for fields that have been removed from the model definition.
+        """
+        management.call_command(
+            'loaddata',
+            'sequence_extra_xml',
+            ignore=True,
+            verbosity=0,
+            commit=False
+        )
+        self.assertEqual(Animal.specimens.all()[0].name, 'Wolf')
+
     @skipIfDBFeature('interprets_empty_strings_as_nulls')
     def test_pretty_print_xml(self):
         """