Fixed #6170 -- Ensured that a useful exception is raised when a regex is invalid in the URLConf.

Thanks to abrahamson.j for the report, to guettli for initial work on the patch, and to David Gouldin for the new patch and test.

3 files changed, 17 insertions, 1 deletions

diff --git a/django/core/urlresolvers.py b/django/core/urlresolvers.py
index 625ec6348b..58213a3a73 100644
--- a/django/core/urlresolvers.py
+++ b/django/core/urlresolvers.py
@@ -160,10 +160,16 @@ class LocaleRegexProvider(object):
         language_code = get_language()
         if language_code not in self._regex_dict:
             if isinstance(self._regex, basestring):
-                compiled_regex = re.compile(self._regex, re.UNICODE)
+                regex = self._regex
             else:
                 regex = force_unicode(self._regex)
+            try:
                 compiled_regex = re.compile(regex, re.UNICODE)
+            except re.error, e:
+                raise ImproperlyConfigured(
+                    u'"%s" is not a valid regular expression: %s' %
+                    (regex, unicode(e)))
+
             self._regex_dict[language_code] = compiled_regex
         return self._regex_dict[language_code]
 
diff --git a/tests/regressiontests/urlpatterns_reverse/erroneous_urls.py b/tests/regressiontests/urlpatterns_reverse/erroneous_urls.py
index 8e6433e16e..d1e4f3db5d 100644
--- a/tests/regressiontests/urlpatterns_reverse/erroneous_urls.py
+++ b/tests/regressiontests/urlpatterns_reverse/erroneous_urls.py
@@ -11,4 +11,6 @@ urlpatterns = patterns('',
     url(r'uncallable/$', 'regressiontests.urlpatterns_reverse.views.uncallable'),
     # Module does not exist
     url(r'missing_outer/$', 'regressiontests.urlpatterns_reverse.missing_module.missing_view'),
+    # Regex contains an error (refs #6170)
+    url(r'(regex_error/$', 'regressiontestes.urlpatterns_reverse.views.empty_view'),
 )
diff --git a/tests/regressiontests/urlpatterns_reverse/tests.py b/tests/regressiontests/urlpatterns_reverse/tests.py
index bb25806830..500a0e0327 100644
--- a/tests/regressiontests/urlpatterns_reverse/tests.py
+++ b/tests/regressiontests/urlpatterns_reverse/tests.py
@@ -511,3 +511,11 @@ class ErroneousViewTests(TestCase):
         self.assertRaises(ViewDoesNotExist, self.client.get, '/missing_outer/')
         self.assertRaises(ViewDoesNotExist, self.client.get, '/uncallable/')
 
+    def test_erroneous_reverse(self):
+        """
+        Ensure that a useful exception is raised when a regex is invalid in the
+        URLConf.
+        Refs #6170.
+        """
+        # The regex error will be hit before NoReverseMatch can be raised
+        self.assertRaises(ImproperlyConfigured, reverse, 'whatever blah blah')