Fixed #36708 -- Initialized formset to None in ChangeList.__init__().

Thanks Antoliny for the review.

3 files changed, 7 insertions, 19 deletions

diff --git a/django/contrib/admin/options.py b/django/contrib/admin/options.py
index 6c202c8e61..2de07fde7e 100644
--- a/django/contrib/admin/options.py
+++ b/django/contrib/admin/options.py
@@ -2050,11 +2050,6 @@ class ModelAdmin(BaseModelAdmin):
             # me back" button on the action confirmation page.
             return HttpResponseRedirect(request.get_full_path())
 
-        # If we're allowing changelist editing, we need to construct a formset
-        # for the changelist given all the fields to be edited. Then we'll
-        # use the formset to validate/process POSTed data.
-        formset = cl.formset = None
-
         # Handle POSTed bulk-edit data.
         if request.method == "POST" and cl.list_editable and "_save" in request.POST:
             if not self.has_change_permission(request):
@@ -2063,13 +2058,11 @@ class ModelAdmin(BaseModelAdmin):
             modified_objects = self._get_list_editable_queryset(
                 request, FormSet.get_default_prefix()
             )
-            formset = cl.formset = FormSet(
-                request.POST, request.FILES, queryset=modified_objects
-            )
-            if formset.is_valid():
+            cl.formset = FormSet(request.POST, request.FILES, queryset=modified_objects)
+            if cl.formset.is_valid():
                 changecount = 0
                 with transaction.atomic(using=router.db_for_write(self.model)):
-                    for form in formset.forms:
+                    for form in cl.formset.forms:
                         if form.has_changed():
                             obj = self.save_form(request, form, change=True)
                             self.save_model(request, obj, form, change=True)
@@ -2095,11 +2088,11 @@ class ModelAdmin(BaseModelAdmin):
         # Handle GET -- construct a formset for display.
         elif cl.list_editable and self.has_change_permission(request):
             FormSet = self.get_changelist_formset(request)
-            formset = cl.formset = FormSet(queryset=cl.result_list)
+            cl.formset = FormSet(queryset=cl.result_list)
 
         # Build the list of media to be used by the formset.
-        if formset:
-            media = self.media + formset.media
+        if cl.formset:
+            media = self.media + cl.formset.media
         else:
             media = self.media
 
diff --git a/django/contrib/admin/views/main.py b/django/contrib/admin/views/main.py
index 8c9118808e..40a6b3bf3a 100644
--- a/django/contrib/admin/views/main.py
+++ b/django/contrib/admin/views/main.py
@@ -101,7 +101,7 @@ class ChangeList:
         self.preserved_filters = model_admin.get_preserved_filters(request)
         self.sortable_by = sortable_by
         self.search_help_text = search_help_text
-
+        self.formset = None
         # Get search parameters from the query string.
         _search_form = self.search_form_class(request.GET)
         if not _search_form.is_valid():
diff --git a/tests/admin_changelist/tests.py b/tests/admin_changelist/tests.py
index 68f6ca453e..319d6259f6 100644
--- a/tests/admin_changelist/tests.py
+++ b/tests/admin_changelist/tests.py
@@ -240,7 +240,6 @@ class ChangeListTests(TestCase):
         request.user = self.superuser
         m = ChildAdmin(Child, custom_site)
         cl = m.get_changelist_instance(request)
-        cl.formset = None
         template = Template(
             "{% load admin_list %}{% spaceless %}{% result_list cl %}{% endspaceless %}"
         )
@@ -285,7 +284,6 @@ class ChangeListTests(TestCase):
         admin.site.empty_value_display = "???"
         m = ChildAdmin(Child, admin.site)
         cl = m.get_changelist_instance(request)
-        cl.formset = None
         template = Template(
             "{% load admin_list %}{% spaceless %}{% result_list cl %}{% endspaceless %}"
         )
@@ -310,7 +308,6 @@ class ChangeListTests(TestCase):
         request.user = self.superuser
         m = EmptyValueChildAdmin(Child, admin.site)
         cl = m.get_changelist_instance(request)
-        cl.formset = None
         template = Template(
             "{% load admin_list %}{% spaceless %}{% result_list cl %}{% endspaceless %}"
         )
@@ -341,7 +338,6 @@ class ChangeListTests(TestCase):
         request.user = self.superuser
         m = ChildAdmin(Child, custom_site)
         cl = m.get_changelist_instance(request)
-        cl.formset = None
         template = Template(
             "{% load admin_list %}{% spaceless %}{% result_list cl %}{% endspaceless %}"
         )
@@ -370,7 +366,6 @@ class ChangeListTests(TestCase):
         request = self._mocked_authenticated_request("/grandchild/", self.superuser)
         m = GrandChildAdmin(GrandChild, custom_site)
         cl = m.get_changelist_instance(request)
-        cl.formset = None
         template = Template(
             "{% load admin_list %}{% spaceless %}{% result_list cl %}{% endspaceless %}"
         )