[4.2.x] Fixed #34512 -- Restored breadcrumbs on admin app index view.

Thanks Adam (ataylor32) for the report.

Regression in 872b611.
Backport of 9440f6b from main

django/contrib/admin/templates/admin/app_index.html

@@ -4,14 +4,16 @@
 {% block bodyclass %}{{ block.super }} app-{{ app_label }}{% endblock %}
 
 {% if not is_popup %}
-{% block breadcrumbs %}
-<div class="breadcrumbs">
-<a href="{% url 'admin:index' %}">{% translate 'Home' %}</a>
-&rsaquo;
-{% for app in app_list %}
-{{ app.name }}
-{% endfor %}
-</div>
+{% block nav-breadcrumbs %}
+  <nav aria-label="{% translate 'Breadcrumbs' %}">
+    <div class="breadcrumbs">
+      <a href="{% url 'admin:index' %}">{% translate 'Home' %}</a>
+      &rsaquo;
+      {% for app in app_list %}
+        {{ app.name }}
+      {% endfor %}
+    </div>
+  </nav>
 {% endblock %}
 {% endif %}
 

docs/releases/4.2.1.txt

@@ -44,3 +44,6 @@ Bugfixes
 
 * Fixed a regression in Django 4.2 that caused incorrect ``ClearableFileInput``
   margins in the admin (:ticket:`34506`).
+
+* Fixed a regression in Django 4.2 where breadcrumbs didn't appear on admin
+  site app index views (:ticket:`34512`).

tests/admin_views/test_breadcrumbs.py

@@ -23,3 +23,7 @@ def test_breadcrumbs_absent(self):
     def test_breadcrumbs_present(self):
         response = self.client.get(reverse("admin:auth_user_add"))
         self.assertContains(response, '<nav aria-label="Breadcrumbs">')
+        response = self.client.get(
+            reverse("admin:app_list", kwargs={"app_label": "auth"})
+        )
+        self.assertContains(response, '<nav aria-label="Breadcrumbs">')