From 367bfaa5226eaae3278989e63f16063d5cc46cd8 Mon Sep 17 00:00:00 2001
From: Florian Apolloner <florian@apolloner.eu>
Date: Tue, 14 Aug 2012 21:12:08 +0200
Subject: [PATCH] Don't swallow AttributeError in
 core.urlresolvers.get_callable.

---
 django/core/urlresolvers.py                   | 27 +++++++++++--------
 .../urlpatterns_reverse/tests.py              | 18 +++++++++++--
 .../urlpatterns_reverse/views_broken.py       |  2 ++
 3 files changed, 34 insertions(+), 13 deletions(-)
 create mode 100644 tests/regressiontests/urlpatterns_reverse/views_broken.py

diff --git a/django/core/urlresolvers.py b/django/core/urlresolvers.py
index 1498c9989d..b83f2f51b0 100644
--- a/django/core/urlresolvers.py
+++ b/django/core/urlresolvers.py
@@ -89,18 +89,11 @@ def get_callable(lookup_view, can_fail=False):
     """
     if not callable(lookup_view):
         mod_name, func_name = get_mod_func(lookup_view)
+        if func_name == '':
+            return lookup_view
+
         try:
-            if func_name != '':
-                lookup_view = getattr(import_module(mod_name), func_name)
-                if not callable(lookup_view):
-                    raise ViewDoesNotExist(
-                        "Could not import %s.%s. View is not callable." %
-                        (mod_name, func_name))
-        except AttributeError:
-            if not can_fail:
-                raise ViewDoesNotExist(
-                    "Could not import %s. View does not exist in module %s." %
-                    (lookup_view, mod_name))
+            mod = import_module(mod_name)
         except ImportError:
             parentmod, submod = get_mod_func(mod_name)
             if (not can_fail and submod != '' and
@@ -110,6 +103,18 @@ def get_callable(lookup_view, can_fail=False):
                     (lookup_view, mod_name))
             if not can_fail:
                 raise
+        else:
+            try:
+                lookup_view = getattr(mod, func_name)
+                if not callable(lookup_view):
+                    raise ViewDoesNotExist(
+                        "Could not import %s.%s. View is not callable." %
+                        (mod_name, func_name))
+            except AttributeError:
+                if not can_fail:
+                    raise ViewDoesNotExist(
+                        "Could not import %s. View does not exist in module %s." %
+                        (lookup_view, mod_name))
     return lookup_view
 get_callable = memoize(get_callable, _callable_cache, 1)
 
diff --git a/tests/regressiontests/urlpatterns_reverse/tests.py b/tests/regressiontests/urlpatterns_reverse/tests.py
index 207cc56488..b9c64183e5 100644
--- a/tests/regressiontests/urlpatterns_reverse/tests.py
+++ b/tests/regressiontests/urlpatterns_reverse/tests.py
@@ -5,8 +5,9 @@ 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, NoReverseMatch,
-    Resolver404, ResolverMatch, RegexURLResolver, RegexURLPattern)
+from django.core.urlresolvers import (reverse, resolve, get_callable,
+    NoReverseMatch, Resolver404, ResolverMatch, RegexURLResolver,
+    RegexURLPattern)
 from django.http import HttpResponseRedirect, HttpResponsePermanentRedirect
 from django.shortcuts import redirect
 from django.test import TestCase
@@ -519,3 +520,16 @@ class ErroneousViewTests(TestCase):
         """
         # The regex error will be hit before NoReverseMatch can be raised
         self.assertRaises(ImproperlyConfigured, reverse, 'whatever blah blah')
+
+class ViewLoadingTests(TestCase):
+    def test_view_loading(self):
+        # A missing view (identified by an AttributeError) should raise
+        # ViewDoesNotExist, ...
+        self.assertRaisesRegexp(ViewDoesNotExist, ".*View does not exist in.*",
+            get_callable,
+            'regressiontests.urlpatterns_reverse.views.i_should_not_exist')
+        # ... but if the AttributeError is caused by something else don't
+        # swallow it.
+        self.assertRaises(AttributeError, get_callable,
+            'regressiontests.urlpatterns_reverse.views_broken.i_am_broken')
+
diff --git a/tests/regressiontests/urlpatterns_reverse/views_broken.py b/tests/regressiontests/urlpatterns_reverse/views_broken.py
new file mode 100644
index 0000000000..4953aab239
--- /dev/null
+++ b/tests/regressiontests/urlpatterns_reverse/views_broken.py
@@ -0,0 +1,2 @@
+# I just raise an AttributeError to confuse the view loading mechanism
+raise AttributeError('I am here to confuse django.core.urlresolvers.get_callable')