assertTemplateUsed asserts against template partial name regardless of origin

[Jacob Walls]

Currently, you can provide a named template partial like "hello" to assertTemplateUsed, which scrupulously complies with its doc'd intention to assert against names, but I can imagine wanting to provide the "qualified" path like my_page.html#hello:

diff --git a/tests/test_utils/templates/template_used/partials.html b/tests/test_utils/templates/template_used/partials.html
new file mode 100644
index 0000000000..5c8db3d657
--- /dev/null
+++ b/tests/test_utils/templates/template_used/partials.html
@@ -0,0 +1,5 @@
+{% partialdef hello %}
+<p>Hello</p>
+{% endpartialdef %}

diff --git a/tests/test_utils/tests.py b/tests/test_utils/tests.py
index 9c22b61b4f..f7500ddc22 100644
--- a/tests/test_utils/tests.py
+++ b/tests/test_utils/tests.py
@@ -510,6 +510,14 @@ class AssertTemplateUsedContextManagerTests(SimpleTestCase):
             render_to_string("template_used/base.html")
             render_to_string("template_used/base.html")
 
+        # passes
+        with self.assertTemplateUsed("hello"):
+            render_to_string("template_used/partials.html#hello")
+
+        # fails
+        with self.assertTemplateUsed("template_used/partials.html#hello"):
+            render_to_string("template_used/partials.html#hello")
+
     def test_nested_usage(self):
         with self.assertTemplateUsed("template_used/base.html"):
             with self.assertTemplateUsed("template_used/include.html"):

Notice the hint "Actual template(s) used: hello" does not point to the origin, really.

AssertionError: False is not true : Template 'template_used/partials.html#hello' was not a template used to render the response. Actual template(s) used: hello

And if we regard the unqualified way as dubious, I'm suggesting we should yank it before 6.0.

The fix doesn't look to be invasive. Curious to hear from others.