Ticket #9427: admin_autodiscover_impfix3.patch

django/contrib/admin/__init__.py

@@ -9 +9 @@
     may want.
     """
     import imp
+    import sys
     from django.conf import settings
 
     for app in settings.INSTALLED_APPS:
@@ -25 +26 @@
             app_path = __import__(app, {}, {}, [app.split('.')[-1]]).__path__
         except AttributeError:
             continue
-
-        # Step 2: use imp.find_module to find the app's admin.py. For some
-        # reason imp.find_module raises ImportError if the app can't be found
-        # but doesn't actually try to import the module. So skip this app if
-        # its admin.py doesn't exist
+            
+        # Import the app's admin module.
         try:
-            imp.find_module('admin', app_path)
+            __import__("%s.admin" % app)
         except ImportError:
-            continue
-
-        # Step 3: import the app's admin file. If this has errors we want them
-        # to bubble up.
-        __import__("%s.admin" % app)
+            # The admin module may be raising an ImportError itself, so if
+            # this is the case, we want that error to bubble up.  However, if
+            # this app simply does not provide an admin module, we want to
+            # silently continue to the next app.
+            #
+            # Checking to see if this app has an admin module requires one of
+            # two different approaches.  If this app was imported through the
+            # use of a custom importer, we need to use that importer's
+            # find_module method, otherwise, we can just use imp.find_module.
+            # (imp does not have support for custom import hooks. For details,
+            # see the section titled "Integration with the 'imp' module" at
+            # http://www.python.org/dev/peps/pep-0302/)
+            #
+            # imp.find_module will raise an ImportError if it fails to find
+            # the specified module, but a custom importer will return None (as
+            # defined in PEP 302).
+            importer = sys.path_importer_cache.get(app_path[0], None) or imp
+            try:
+                if importer.find_module('admin', app_path) is not None:
+                    # The admin module exists, so let the ImportError bubble up.
+                    raise
+            except ImportError:
+                # The module failed to import and doesn't exist, so move on.
+                continue