Fixed #28869 -- Made tagged test classes and methods inherit tags from parents.

tests/test_runner_apps/tagged/tests_inheritance.py

@@ -0,0 +1,29 @@
+from unittest import TestCase
+
+from django.test import tag
+
+
+@tag('foo')
+class FooBase(TestCase):
+    pass
+
+
+class Foo(FooBase):
+
+    def test_no_new_tags(self):
+        pass
+
+    @tag('baz')
+    def test_new_func_tag(self):
+        pass
+
+
+@tag('bar')
+class FooBar(FooBase):
+
+    def test_new_class_tag_only(self):
+        pass
+
+    @tag('baz')
+    def test_new_class_and_func_tags(self):
+        pass