Fixed #17892 -- Do not include whole RegexURLPattern lists in RegexURLResolver repr

Thanks milosu for the report and the initial patch.

django/core/urlresolvers.py

@@ -245,8 +245,13 @@ class RegexURLResolver(LocaleRegexProvider):
         self._app_dict = {}
 
     def __repr__(self):
+        if isinstance(self.urlconf_name, list) and len(self.urlconf_name):
+            # Don't bother to output the whole list, it can be huge
+            urlconf_repr = '<%s list>' % self.urlconf_name[0].__class__.__name__
+        else:
+            urlconf_repr = repr(self.urlconf_name)
         return force_str('<%s %s (%s:%s) %s>' % (
-            self.__class__.__name__, self.urlconf_name, self.app_name,
+            self.__class__.__name__, urlconf_repr, self.app_name,
             self.namespace, self.regex.pattern))
 
     def _populate(self):

tests/regressiontests/urlpatterns_reverse/tests.py

@@ -6,7 +6,7 @@ from __future__ import absolute_import, unicode_literals
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
 from django.core.urlresolvers import (reverse, resolve, get_callable,
-    NoReverseMatch, Resolver404, ResolverMatch, RegexURLResolver,
+    get_resolver, NoReverseMatch, Resolver404, ResolverMatch, RegexURLResolver,
     RegexURLPattern)
 from django.http import HttpResponseRedirect, HttpResponsePermanentRedirect
 from django.shortcuts import redirect
@@ -172,6 +172,16 @@ class URLPatternReverse(TestCase):
         self.assertRaises(NoReverseMatch, reverse, None)
 
 class ResolverTests(unittest.TestCase):
+    def test_resolver_repr(self):
+        """
+        Test repr of RegexURLResolver, especially when urlconf_name is a list
+        (#17892).
+        """
+        # Pick a resolver from a namespaced urlconf
+        resolver = get_resolver('regressiontests.urlpatterns_reverse.namespace_urls')
+        sub_resolver = resolver.namespace_dict['test-ns1'][1]
+        self.assertIn('<RegexURLPattern list>', repr(sub_resolver))
+
     def test_non_regex(self):
         """
         Verifies that we raise a Resolver404 if what we are resolving doesn't