Fixed #16734 -- Set script prefix even outside of requests

Thanks Tim Graham for the review.

tests/user_commands/tests.py

@@ -1,5 +1,7 @@
 import os
 
+from admin_scripts.tests import AdminScriptTestCase
+
 from django.apps import apps
 from django.core import management
 from django.core.management import BaseCommand, CommandError, find_commands
@@ -159,6 +161,23 @@ class CommandTests(SimpleTestCase):
             BaseCommand.check = saved_check
 
 
+class CommandRunTests(AdminScriptTestCase):
+    """
+    Tests that need to run by simulating the command line, not by call_command.
+    """
+    def tearDown(self):
+        self.remove_settings('settings.py')
+
+    def test_script_prefix_set_in_commands(self):
+        self.write_settings('settings.py', apps=['user_commands'], sdict={
+            'ROOT_URLCONF': '"user_commands.urls"',
+            'FORCE_SCRIPT_NAME': '"/PREFIX/"',
+        })
+        out, err = self.run_manage(['reverse_url'])
+        self.assertNoOutput(err)
+        self.assertEqual(out.strip(), '/PREFIX/some/url/')
+
+
 class UtilsTests(SimpleTestCase):
 
     def test_no_existent_external_program(self):