From fac27853418699116304ad8d77270fe9a20873dc Mon Sep 17 00:00:00 2001
From: Ion Scerbatiuc <ion@rover.com>
Date: Thu, 19 Mar 2015 16:12:28 -0700
Subject: [PATCH] Handling the fallback in `reverse`

---
 rest_framework/reverse.py    |  9 ++++++++-
 rest_framework/versioning.py | 12 +-----------
 tests/test_reverse.py        | 27 +++++++++++++++++++++++++++
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/rest_framework/reverse.py b/rest_framework/reverse.py
index a251d99d6..e6d3f5634 100644
--- a/rest_framework/reverse.py
+++ b/rest_framework/reverse.py
@@ -3,6 +3,7 @@ Provide urlresolver functions that return fully qualified URLs or view names
 """
 from __future__ import unicode_literals
 from django.core.urlresolvers import reverse as django_reverse
+from django.core.urlresolvers import NoReverseMatch
 from django.utils import six
 from django.utils.functional import lazy
 
@@ -15,7 +16,13 @@ def reverse(viewname, args=None, kwargs=None, request=None, format=None, **extra
     """
     scheme = getattr(request, 'versioning_scheme', None)
     if scheme is not None:
-        return scheme.reverse(viewname, args, kwargs, request, format, **extra)
+        try:
+            return scheme.reverse(viewname, args, kwargs, request, format, **extra)
+        except NoReverseMatch:
+            # In case the versioning scheme reversal fails, fallback to the
+            # default implementation
+            pass
+
     return _reverse(viewname, args, kwargs, request, format, **extra)
 
 
diff --git a/rest_framework/versioning.py b/rest_framework/versioning.py
index 6f7952c03..51b886f38 100644
--- a/rest_framework/versioning.py
+++ b/rest_framework/versioning.py
@@ -1,7 +1,6 @@
 # coding: utf-8
 from __future__ import unicode_literals
 from django.utils.translation import ugettext_lazy as _
-from django.core.urlresolvers import NoReverseMatch
 from rest_framework import exceptions
 from rest_framework.compat import unicode_http_header
 from rest_framework.reverse import _reverse
@@ -123,16 +122,7 @@ class NamespaceVersioning(BaseVersioning):
 
     def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):
         if request.version is not None:
-            versioned_viewname = self.get_versioned_viewname(viewname, request)
-            try:
-                return super(NamespaceVersioning, self).reverse(
-                    versioned_viewname, args, kwargs, request, format, **extra
-                )
-            except NoReverseMatch:
-                # If the versioned viewname lookup fails, fallback to the
-                # default reversal, since it may be a non-API view
-                pass
-
+            viewname = self.get_versioned_viewname(viewname, request)
         return super(NamespaceVersioning, self).reverse(
             viewname, args, kwargs, request, format, **extra
         )
diff --git a/tests/test_reverse.py b/tests/test_reverse.py
index 675a9d5a0..08c270239 100644
--- a/tests/test_reverse.py
+++ b/tests/test_reverse.py
@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 from django.conf.urls import patterns, url
+from django.core.urlresolvers import NoReverseMatch
 from django.test import TestCase
 from rest_framework.reverse import reverse
 from rest_framework.test import APIRequestFactory
@@ -16,6 +17,18 @@ urlpatterns = patterns(
 )
 
 
+class MockVersioningScheme(object):
+
+    def __init__(self, raise_error=False):
+        self.raise_error = raise_error
+
+    def reverse(self, *args, **kwargs):
+        if self.raise_error:
+            raise NoReverseMatch()
+
+        return 'http://scheme-reversed/view'
+
+
 class ReverseTests(TestCase):
     """
     Tests for fully qualified URLs when using `reverse`.
@@ -26,3 +39,17 @@ class ReverseTests(TestCase):
         request = factory.get('/view')
         url = reverse('view', request=request)
         self.assertEqual(url, 'http://testserver/view')
+
+    def test_reverse_with_versioning_scheme(self):
+        request = factory.get('/view')
+        request.versioning_scheme = MockVersioningScheme()
+
+        url = reverse('view', request=request)
+        self.assertEqual(url, 'http://scheme-reversed/view')
+
+    def test_reverse_with_versioning_scheme_fallback_to_default_on_error(self):
+        request = factory.get('/view')
+        request.versioning_scheme = MockVersioningScheme(raise_error=True)
+
+        url = reverse('view', request=request)
+        self.assertEqual(url, 'http://testserver/view')