Fixed #24476 -- Added context manager/decorator for overriding script prefix.

Tests were using an undocumented keyword argument for easily overriding
script prefix while reversing. This is now changed into a test utility
which can be used as decorator or context manager.

2 files changed, 23 insertions, 3 deletions

diff --git a/django/core/urlresolvers.py b/django/core/urlresolvers.py
index cf42768add..563d4a7ade 100644
--- a/django/core/urlresolvers.py
+++ b/django/core/urlresolvers.py
@@ -527,15 +527,14 @@ def resolve(path, urlconf=None):
     return get_resolver(urlconf).resolve(path)
 
 
-def reverse(viewname, urlconf=None, args=None, kwargs=None, prefix=None, current_app=None):
+def reverse(viewname, urlconf=None, args=None, kwargs=None, current_app=None):
     if urlconf is None:
         urlconf = get_urlconf()
     resolver = get_resolver(urlconf)
     args = args or []
     kwargs = kwargs or {}
 
-    if prefix is None:
-        prefix = get_script_prefix()
+    prefix = get_script_prefix()
 
     if not isinstance(viewname, six.string_types):
         view = viewname
diff --git a/django/test/utils.py b/django/test/utils.py
index 5224bcfb71..0101919d11 100644
--- a/django/test/utils.py
+++ b/django/test/utils.py
@@ -12,11 +12,13 @@ from django.apps import apps
 from django.conf import UserSettingsHolder, settings
 from django.core import mail
 from django.core.signals import request_started
+from django.core.urlresolvers import get_script_prefix, set_script_prefix
 from django.db import reset_queries
 from django.http import request
 from django.template import Template
 from django.test.signals import setting_changed, template_rendered
 from django.utils import six
+from django.utils.decorators import ContextDecorator
 from django.utils.encoding import force_str
 from django.utils.translation import deactivate
 
@@ -595,3 +597,22 @@ def require_jinja2(test_func):
         'OPTIONS': {'keep_trailing_newline': True},
     }])(test_func)
     return test_func
+
+
+class ScriptPrefix(ContextDecorator):
+    def __enter__(self):
+        set_script_prefix(self.prefix)
+
+    def __exit__(self, exc_type, exc_val, traceback):
+        set_script_prefix(self.old_prefix)
+
+    def __init__(self, prefix):
+        self.prefix = prefix
+        self.old_prefix = get_script_prefix()
+
+
+def override_script_prefix(prefix):
+    """
+    Decorator or context manager to temporary override the script prefix.
+    """
+    return ScriptPrefix(prefix)