Fixed #13335: Adjusted the r12950 fix to properly handle import errors resulting from nested calls to load_app.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12972 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/loading.py

@@ -75,16 +75,23 @@ class AppCache(object):
         app_module = import_module(app_name)
         try:
             imp.find_module('models', app_module.__path__)
+        except ImportError: 
+            self.nesting_level -= 1
+            # App has no models module, that's not a problem.
+            return None
+        try:
+            models = import_module('.models', app_name)
         except ImportError:
             self.nesting_level -= 1
             if can_postpone:
-                # Either the app has no models, or the package is still being
+                # Either the app has an error, or the package is still being
                 # imported by Python and the model module isn't available yet.
                 # We will check again once all the recursion has finished (in
                 # populate).
                 self.postponed.append(app_name)
                 return None
-        models = import_module('.models', app_name)
+            else:
+                raise
         self.nesting_level -= 1
         if models not in self.app_store:
             self.app_store[models] = len(self.app_store)

tests/regressiontests/admin_scripts/complex_app/admin/foo.py

@@ -0,0 +1,3 @@
+from django.contrib import admin
+from admin_scripts.complex_app.models.foo import Foo
+admin.site.register(Foo)

tests/regressiontests/admin_scripts/complex_app/models/__init__.py

@@ -0,0 +1,4 @@
+from admin_scripts.complex_app.models.bar import Bar
+from admin_scripts.complex_app.models.foo import Foo
+
+__all__ = ['Foo', 'Bar']

tests/regressiontests/admin_scripts/complex_app/models/bar.py

@@ -0,0 +1,7 @@
+from django.db import models
+
+from ..admin import foo
+class Bar(models.Model):
+    name = models.CharField(max_length=5)
+    class Meta:
+        app_label = 'complex_app'

tests/regressiontests/admin_scripts/complex_app/models/foo.py

@@ -0,0 +1,6 @@
+from django.db import models
+
+class Foo(models.Model):
+    name = models.CharField(max_length=5)
+    class Meta:
+        app_label = 'complex_app'

tests/regressiontests/admin_scripts/simple_app/models.py

@@ -0,0 +1 @@
+from admin_scripts.complex_app.models.bar import Bar

tests/regressiontests/admin_scripts/tests.py

@@ -957,7 +957,7 @@ class ManageMultipleSettings(AdminScriptTestCase):
         self.assertOutput(err, "Unknown command: 'noargs_command'")
 
 
-class ManageValidateImportErrorsReported(AdminScriptTestCase):
+class ManageValidate(AdminScriptTestCase):
     def tearDown(self):
         self.remove_settings('settings.py')
 
@@ -977,6 +977,16 @@ class ManageValidateImportErrorsReported(AdminScriptTestCase):
         self.assertNoOutput(out)
         self.assertOutput(err, 'ImportError')
 
+    def test_complex_app(self):
+        "manage.py validate does not raise an ImportError validating a complex app with nested calls to load_app"
+        self.write_settings('settings.py',
+            apps=['admin_scripts.complex_app', 'admin_scripts.simple_app'],
+            sdict={'DEBUG': True})
+        args = ['validate']
+        out, err = self.run_manage(args)
+        self.assertNoOutput(err)
+        self.assertOutput(out, '0 errors found')
+
 
 ##########################################################################
 # COMMAND PROCESSING TESTS