Fix CopyView not prefilling the form data for snippets

wagtail/admin/views/generic/__init__.py

@@ -15,6 +15,7 @@
 )
 from .models import (  # noqa: F401
     CopyView,
+    CopyViewMixin,
     CreateView,
     DeleteView,
     EditView,

wagtail/admin/views/generic/models.py

@@ -688,12 +688,18 @@ def form_invalid(self, form):
         return super().form_invalid(form)
 
 
-class CopyView(CreateView):
+class CopyViewMixin:
     def get_object(self, queryset=None):
-        return get_object_or_404(self.model, pk=unquote(str(self.kwargs["pk"])))
+        return get_object_or_404(
+            self.model, pk=unquote(str(self.kwargs[self.pk_url_kwarg]))
+        )
 
-    def get_form_kwargs(self):
-        return {**super().get_form_kwargs(), "instance": self.get_object()}
+    def get_initial_form_instance(self):
+        return self.get_object()
+
+
+class CopyView(CopyViewMixin, CreateView):
+    pass
 
 
 class EditView(

wagtail/snippets/tests/test_snippets.py

@@ -35,7 +35,6 @@
 )
 from wagtail.snippets.blocks import SnippetChooserBlock
 from wagtail.snippets.models import SNIPPET_MODELS, register_snippet
-from wagtail.snippets.views.snippets import CopyView
 from wagtail.snippets.widgets import (
     AdminSnippetChooser,
     SnippetChooserAdapter,
@@ -974,20 +973,29 @@ def setUp(self):
             StandardSnippet.snippet_viewset.get_url_name("copy"),
             args=(self.snippet.pk,),
         )
-        self.login()
+        self.user = self.login()
+
+    def test_without_permission(self):
+        self.user.is_superuser = False
+        self.user.save()
+        admin_permission = Permission.objects.get(
+            content_type__app_label="wagtailadmin", codename="access_admin"
+        )
+        self.user.user_permissions.add(admin_permission)
 
-    def test_simple(self):
+        response = self.client.get(self.url)
+        self.assertEqual(response.status_code, 302)
+        self.assertRedirects(response, reverse("wagtailadmin_home"))
+
+    def test_form_is_prefilled(self):
         response = self.client.get(self.url)
         self.assertEqual(response.status_code, 200)
         self.assertTemplateUsed(response, "wagtailsnippets/snippets/create.html")
 
-    def test_form_prefilled(self):
-        request = RequestFactory().get(self.url)
-        view = CopyView()
-        view.model = StandardSnippet
-        view.setup(request, pk=self.snippet.pk)
-
-        self.assertEqual(view._get_initial_form_instance(), self.snippet)
+        # Ensure form is prefilled
+        soup = self.get_soup(response.content)
+        text_input = soup.select_one('input[name="text"]')
+        self.assertEqual(text_input.attrs.get("value"), "Test snippet")
 
 
 @override_settings(WAGTAIL_I18N_ENABLED=True)

wagtail/snippets/views/snippets.py

@@ -5,7 +5,7 @@
 from django.core import checks
 from django.core.exceptions import ImproperlyConfigured, PermissionDenied
 from django.http import Http404
-from django.shortcuts import get_object_or_404, redirect
+from django.shortcuts import redirect
 from django.urls import path, re_path, reverse, reverse_lazy
 from django.utils.functional import cached_property
 from django.utils.text import capfirst
@@ -262,16 +262,8 @@ def get_context_data(self, **kwargs):
         return context
 
 
-class CopyView(CreateView):
-    def get_object(self):
-        return get_object_or_404(self.model, pk=self.kwargs["pk"])
-
-    def _get_initial_form_instance(self):
-        instance = self.get_object()
-        # Set locale of the new instance
-        if self.locale:
-            instance.locale = self.locale
-        return instance
+class CopyView(generic.CopyViewMixin, CreateView):
+    pass
 
 
 class EditView(generic.CreateEditViewOptionalFeaturesMixin, generic.EditView):