From b18bb65fd2ba0d4f3a0c3a15355c2a9c5afa9969 Mon Sep 17 00:00:00 2001
From: Aymeric Augustin <aymeric.augustin@m4x.org>
Date: Wed, 5 Aug 2015 11:06:26 +0200
Subject: [PATCH] [1.8.x] Accounted for error files in the autoreloader.

* When some old files contain errors, the second call to
  gen_filenames() should return them.
* When some new files contain errors, the first call to
  gen_filenames(only_new=True) should return them.

Backport of 23620cb8e0 from master
---
 django/utils/autoreload.py           |  4 +--
 tests/utils_tests/test_autoreload.py | 40 ++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/django/utils/autoreload.py b/django/utils/autoreload.py
index 5cb7fd0bac..807a1f76ba 100644
--- a/django/utils/autoreload.py
+++ b/django/utils/autoreload.py
@@ -95,7 +95,7 @@ def gen_filenames(only_new=False):
         if only_new:
             return []
         else:
-            return _cached_filenames
+            return _cached_filenames + clean_files(_error_files)
 
     new_modules = module_values - _cached_modules
     new_filenames = clean_files(
@@ -122,7 +122,7 @@ def gen_filenames(only_new=False):
     _cached_modules = _cached_modules.union(new_modules)
     _cached_filenames += new_filenames
     if only_new:
-        return new_filenames
+        return new_filenames + clean_files(_error_files)
     else:
         return _cached_filenames + clean_files(_error_files)
 
diff --git a/tests/utils_tests/test_autoreload.py b/tests/utils_tests/test_autoreload.py
index ff4cf63e1c..bd96baa340 100644
--- a/tests/utils_tests/test_autoreload.py
+++ b/tests/utils_tests/test_autoreload.py
@@ -1,4 +1,5 @@
 import os
+import shutil
 import tempfile
 from importlib import import_module
 
@@ -6,6 +7,7 @@ from django import conf
 from django.contrib import admin
 from django.test import TestCase, override_settings
 from django.test.utils import extend_sys_path
+from django.utils import autoreload
 from django.utils._os import npath, upath
 from django.utils.autoreload import gen_filenames
 
@@ -98,3 +100,41 @@ class TestFilenameGenerator(TestCase):
         self.assertIn(npath(filename), gen_filenames())
         os.unlink(filename)
         self.assertNotIn(filename, gen_filenames())
+
+    def test_check_errors(self):
+        """
+        When a file containing an error is imported in a function wrapped by
+        check_errors(), gen_filenames() returns it.
+
+        Run assertions twice to test uncached and cached access.
+        """
+        dirname = tempfile.mkdtemp()
+        filename = os.path.join(dirname, 'test_syntax_error.py')
+        self.addCleanup(shutil.rmtree, dirname)
+        with open(filename, 'w') as f:
+            f.write("Ceci n'est pas du Python.")
+
+        with extend_sys_path(dirname):
+            with self.assertRaises(SyntaxError):
+                autoreload.check_errors(import_module)('test_syntax_error')
+        self.assertIn(npath(filename), gen_filenames())
+        self.assertIn(npath(filename), gen_filenames())
+
+    def test_check_errors_only_new(self):
+        """
+        When a file containing an error is imported in a function wrapped by
+        check_errors(), gen_filenames(only_new=True) returns it.
+
+        Run assertions twice to test uncached and cached access.
+        """
+        dirname = tempfile.mkdtemp()
+        filename = os.path.join(dirname, 'test_syntax_error.py')
+        self.addCleanup(shutil.rmtree, dirname)
+        with open(filename, 'w') as f:
+            f.write("Ceci n'est pas du Python.")
+
+        with extend_sys_path(dirname):
+            with self.assertRaises(SyntaxError):
+                autoreload.check_errors(import_module)('test_syntax_error')
+        self.assertIn(npath(filename), gen_filenames(only_new=True))
+        self.assertNotIn(npath(filename), gen_filenames(only_new=True))