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,