Fixed #21382 - Added "has_original" to stacked inlines.

Report and original patch from jrief.

django/contrib/admin/templates/admin/edit_inline/stacked.html

@@ -4,7 +4,7 @@ <h2>{{ inline_admin_formset.opts.verbose_name_plural|capfirst }}</h2>
 {{ inline_admin_formset.formset.management_form }}
 {{ inline_admin_formset.formset.non_form_errors }}
 
-{% for inline_admin_form in inline_admin_formset %}<div class="inline-related{% if forloop.last %} empty-form last-related{% endif %}" id="{{ inline_admin_formset.formset.prefix }}-{% if not forloop.last %}{{ forloop.counter0 }}{% else %}empty{% endif %}">
+{% for inline_admin_form in inline_admin_formset %}<div class="inline-related{% if inline_admin_form.original or inline_admin_form.show_url %} has_original{% endif %}{% if forloop.last %} empty-form last-related{% endif %}" id="{{ inline_admin_formset.formset.prefix }}-{% if not forloop.last %}{{ forloop.counter0 }}{% else %}empty{% endif %}">
   <h3><b>{{ inline_admin_formset.opts.verbose_name|capfirst }}:</b>&nbsp;<span class="inline_label">{% if inline_admin_form.original %}{{ inline_admin_form.original }}{% else %}#{{ forloop.counter }}{% endif %}</span>
       {% if inline_admin_form.show_url %}<a href="{{ inline_admin_form.absolute_url }}">{% trans "View on site" %}</a>{% endif %}
     {% if inline_admin_formset.formset.can_delete and inline_admin_form.original %}<span class="delete">{{ inline_admin_form.deletion_field.field }} {{ inline_admin_form.deletion_field.label_tag }}</span>{% endif %}

tests/admin_inlines/tests.py

@@ -239,6 +239,21 @@ def test_inline_editable_pk(self):
             '<input class="vIntegerField" id="id_editablepkbook_set-2-0-manual_pk" name="editablepkbook_set-2-0-manual_pk" type="text" />',
              html=True, count=1)
 
+    def test_stacked_inline_edit_form_contains_has_original_class(self):
+        holder = Holder.objects.create(dummy=1)
+        holder.inner_set.create(dummy=1)
+        response = self.client.get('/admin/admin_inlines/holder/%s/' % holder.pk)
+        self.assertContains(
+            response,
+            '<div class="inline-related has_original" id="inner_set-0">',
+            count=1
+        )
+        self.assertContains(
+            response,
+            '<div class="inline-related" id="inner_set-1">',
+            count=1
+        )
+
 
 @override_settings(PASSWORD_HASHERS=('django.contrib.auth.hashers.SHA1PasswordHasher',))
 class TestInlineMedia(TestCase):