Fixed #21221 -- Made form Media and static template tag use staticfiles if installed.

tests/staticfiles_tests/test_forms.py

@@ -0,0 +1,30 @@
+from django.contrib.staticfiles import storage
+from django.forms import Media
+from django.test import SimpleTestCase, override_settings
+from django.utils.six.moves.urllib.parse import urljoin
+
+
+class StaticTestStorage(storage.StaticFilesStorage):
+    def url(self, name):
+        return urljoin('https://example.com/assets/', name)
+
+
+@override_settings(
+    STATIC_URL='http://media.example.com/static/',
+    INSTALLED_APPS=('django.contrib.staticfiles', ),
+    STATICFILES_STORAGE='staticfiles_tests.test_forms.StaticTestStorage',
+)
+class StaticFilesFormsMediaTestCase(SimpleTestCase):
+    def test_absolute_url(self):
+        m = Media(
+            css={'all': ('path/to/css1', '/path/to/css2')},
+            js=('/path/to/js1', 'http://media.other.com/path/to/js2', 'https://secure.other.com/path/to/js3'),
+        )
+        self.assertEqual(
+            str(m),
+            """<link href="https://example.com/assets/path/to/css1" type="text/css" media="all" rel="stylesheet" />
+<link href="/path/to/css2" type="text/css" media="all" rel="stylesheet" />
+<script type="text/javascript" src="/path/to/js1"></script>
+<script type="text/javascript" src="http://media.other.com/path/to/js2"></script>
+<script type="text/javascript" src="https://secure.other.com/path/to/js3"></script>"""
+        )