Fixes PostgreSQL tests.

wagtail/contrib/postgres_search/backend.py

@@ -209,7 +209,8 @@ class PostgresSearchQueryCompiler(BaseSearchQueryCompiler):
         else:
             sub_field_name = None
         for field in fields:
-            if field.field_name == field_name:
+            if isinstance(field, SearchField) \
+                    and field.field_name == field_name:
                 # Note: Searching on a specific related field using
                 # `.search(fields=…)` is not yet supported by Wagtail.
                 # This method anticipates by already implementing it.

wagtail/contrib/postgres_search/models.py

@@ -14,6 +14,8 @@ from .utils import get_descendants_content_types_pks
 
 
 class TextIDGenericRelation(GenericRelation):
+    auto_created = True
+
     def get_content_type_lookup(self, alias, remote_alias):
         field = self.remote_field.model._meta.get_field(
             self.content_type_field_name)

wagtail/wagtailcore/models.py

@@ -1035,7 +1035,7 @@ class Page(six.with_metaclass(PageBase, AbstractPage, index.Indexed, Clusterable
     def copy(self, recursive=False, to=None, update_attrs=None, copy_revisions=True, keep_live=True, user=None):
         # Fill dict with self.specific values
         specific_self = self.specific
-        default_exclude_fields = ['id', 'path', 'depth', 'numchild', 'url_path', 'path']
+        default_exclude_fields = ['id', 'path', 'depth', 'numchild', 'url_path', 'path', 'index_entries']
         exclude_fields = default_exclude_fields + specific_self.exclude_fields_in_copy
         specific_dict = {}