Fixed #18373 - improved handling of Resolver404s from views

When django.core.urlresolvers.resolve was called from a view, failed
and the exception was propagated and rendered by technical_404_response,
the URL mentioned on the page was the current URL instead of the URL
passed to resolve().

Fixed by using the path attribute from the Resolver404 exception instead
of request.path_info. Also cleaned up the exceptions to use standard
named parameters instead of stuffing a dict in args[0]

django/core/urlresolvers.py

@@ -69,8 +69,11 @@ class ResolverMatch(object):
 
 
 class Resolver404(Http404):
-    pass
 
+    def __init__(self, path, tried=None):
+        super(Resolver404, self).__init__()
+        self.path = path
+        self.tried = tried
 
 class NoReverseMatch(Exception):
     pass
@@ -322,7 +325,7 @@ class RegexURLResolver(LocaleRegexProvider):
                 try:
                     sub_match = pattern.resolve(new_path)
                 except Resolver404 as e:
-                    sub_tried = e.args[0].get('tried')
+                    sub_tried = e.tried
                     if sub_tried is not None:
                         tried.extend([pattern] + t for t in sub_tried)
                     else:
@@ -333,8 +336,8 @@ class RegexURLResolver(LocaleRegexProvider):
                         sub_match_dict.update(sub_match.kwargs)
                         return ResolverMatch(sub_match.func, sub_match.args, sub_match_dict, sub_match.url_name, self.app_name or sub_match.app_name, [self.namespace] + sub_match.namespaces)
                     tried.append([pattern])
-            raise Resolver404({'tried': tried, 'path': new_path})
-        raise Resolver404({'path': path})
+            raise Resolver404(new_path, tried=tried)
+        raise Resolver404(path)
 
     @property
     def urlconf_module(self):

django/views/debug.py

@@ -475,9 +475,11 @@ class ExceptionReporter(object):
 def technical_404_response(request, exception):
     "Create a technical 404 error response. The exception should be the Http404."
     try:
-        tried = exception.args[0]['tried']
-    except (IndexError, TypeError, KeyError):
+        tried = exception.tried
+        error_url = exception.path
+    except AttributeError:
         tried = []
+        error_url = request.path_info[1:] # Trim leading slash
     else:
         if (not tried                           # empty URLconf
             or (request.path == '/'
@@ -494,7 +496,7 @@ def technical_404_response(request, exception):
     c = Context({
         'urlconf': urlconf,
         'root_urlconf': settings.ROOT_URLCONF,
-        'request_path': request.path_info[1:],  # Trim leading slash
+        'request_path': error_url,
         'urlpatterns': tried,
         'reason': force_bytes(exception, errors='replace'),
         'request': request,

tests/urlpatterns_reverse/tests.py

@@ -272,10 +272,10 @@ class ResolverTests(unittest.TestCase):
             self.fail('resolve did not raise a 404')
         except Resolver404 as e:
             # make sure we at least matched the root ('/') url resolver:
-            self.assertTrue('tried' in e.args[0])
-            tried = e.args[0]['tried']
-            self.assertEqual(len(e.args[0]['tried']), len(url_types_names), 'Wrong number of tried URLs returned.  Expected %s, got %s.' % (len(url_types_names), len(e.args[0]['tried'])))
-            for tried, expected in zip(e.args[0]['tried'], url_types_names):
+            self.assertTrue(hasattr(e, 'tried'))
+            tried = e.tried
+            self.assertEqual(len(tried), len(url_types_names), 'Wrong number of tried URLs returned.  Expected %s, got %s.' % (len(url_types_names), len(tried)))
+            for tried, expected in zip(tried, url_types_names):
                 for t, e in zip(tried, expected):
                     self.assertIsInstance(t, e['type']), str('%s is not an instance of %s') % (t, e['type'])
                     if 'name' in e:

tests/view_tests/tests/test_debug.py

@@ -69,6 +69,14 @@ class DebugViewTests(TestCase):
         response = self.client.get('/raises404/')
         self.assertEqual(response.status_code, 404)
 
+    def test_raised_404(self):
+        response = self.client.get('/views/raises404/')
+        self.assertContains(response, "<code>not-in-urls</code>, didn't match", status_code=404)
+
+    def test_404_not_in_urls(self):
+        response = self.client.get('/not-in-urls')
+        self.assertContains(response, "<code>not-in-urls</code>, didn't match", status_code=404)
+
     def test_view_exceptions(self):
         for n in range(len(except_args)):
             self.assertRaises(BrokenException, self.client.get,

tests/view_tests/views.py

@@ -57,7 +57,7 @@ def raises403(request):
 
 def raises404(request):
     resolver = get_resolver(None)
-    resolver.resolve('')
+    resolver.resolve('/not-in-urls')
 
 
 def redirect(request):