From 2d2859bec27c9e3994cff6be56dd5fe0f694a24c Mon Sep 17 00:00:00 2001
From: Tom Forbes <tom@tomforb.es>
Date: Sun, 21 Jul 2019 21:55:25 +0100
Subject: [PATCH] [2.2.x] Fixed #30506 -- Fixed crash of autoreloader when path
 contains null characters.

Backport of 2ff517ccb6116c1be6338e6bdcf08a313defc5c7 from master.
---
 django/utils/autoreload.py           | 14 +++++++++-----
 docs/releases/2.2.4.txt              |  3 +++
 tests/utils_tests/test_autoreload.py | 11 +++++++++++
 3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/django/utils/autoreload.py b/django/utils/autoreload.py
index 2fdc2f3f83b..3153f3f14d9 100644
--- a/django/utils/autoreload.py
+++ b/django/utils/autoreload.py
@@ -135,11 +135,15 @@ def iter_modules_and_files(modules, extra_files):
         if not filename:
             continue
         path = pathlib.Path(filename)
-        if not path.exists():
-            # The module could have been removed, don't fail loudly if this
-            # is the case.
-            continue
-        results.add(path.resolve().absolute())
+        try:
+            if not path.exists():
+                # The module could have been removed, don't fail loudly if this
+                # is the case.
+                continue
+            results.add(path.resolve().absolute())
+        except ValueError as e:
+            # Network filesystems may return null bytes in file paths.
+            logger.debug('"%s" raised when resolving path: "%s"' % (str(e), path))
     return frozenset(results)
 
 
diff --git a/docs/releases/2.2.4.txt b/docs/releases/2.2.4.txt
index 0ad92f4ab1c..af0950d7005 100644
--- a/docs/releases/2.2.4.txt
+++ b/docs/releases/2.2.4.txt
@@ -18,3 +18,6 @@ Bugfixes
   :class:`~django.contrib.postgres.fields.DateRangeField` or
   :class:`~django.contrib.postgres.fields.DateTimeRangeField`, if the right
   hand side of an expression is the same type (:ticket:`30621`).
+
+* Fixed a regression in Django 2.2 where auto-reloader crashes if a file path
+  contains nulls characters (``'\x00'``) (:ticket:`30506`).
diff --git a/tests/utils_tests/test_autoreload.py b/tests/utils_tests/test_autoreload.py
index c7308ca53ad..59eb32ed70d 100644
--- a/tests/utils_tests/test_autoreload.py
+++ b/tests/utils_tests/test_autoreload.py
@@ -138,6 +138,17 @@ class TestIterModulesAndFiles(SimpleTestCase):
         fake_main = types.ModuleType('__main__')
         self.assertEqual(autoreload.iter_modules_and_files((fake_main,), frozenset()), frozenset())
 
+    def test_path_with_embedded_null_bytes(self):
+        for path in (
+            'embedded_null_byte\x00.py',
+            'di\x00rectory/embedded_null_byte.py',
+        ):
+            with self.subTest(path=path):
+                self.assertEqual(
+                    autoreload.iter_modules_and_files((), frozenset([path])),
+                    frozenset(),
+                )
+
 
 class TestCommonRoots(SimpleTestCase):
     def test_common_roots(self):