[4.0.x] Fixed #33628 -- Ignored directories with empty names in autoreloader check for template changes.

Regression in 68357b2ca9.

Backport of 62739b6e26 from main.

django/template/autoreload.py

@@ -16,7 +16,7 @@ def get_template_directories():
         if not isinstance(backend, DjangoTemplates):
             continue
 
-        items.update(Path.cwd() / to_path(dir) for dir in backend.engine.dirs)
+        items.update(Path.cwd() / to_path(dir) for dir in backend.engine.dirs if dir)
 
         for loader in backend.engine.template_loaders:
             if not hasattr(loader, "get_dirs"):
@@ -24,7 +24,7 @@ def get_template_directories():
             items.update(
                 Path.cwd() / to_path(directory)
                 for directory in loader.get_dirs()
-                if not is_django_path(directory)
+                if directory and not is_django_path(directory)
             )
     return items
 

docs/releases/3.2.13.txt

@@ -4,4 +4,12 @@ Django 3.2.13 release notes
 
 *April 11, 2022*
 
-Django 3.2.13 fixes two security issues with severity "high" in 3.2.12.
+Django 3.2.13 fixes two security issues with severity "high" in
+3.2.12 and a regression in 3.2.4.
+
+Bugfixes
+========
+
+* Fixed a regression in Django 3.2.4 that caused the auto-reloader to no longer
+  detect changes when the ``DIRS`` option of the ``TEMPLATES`` setting
+  contained an empty string (:ticket:`33628`).

docs/releases/4.0.4.txt

@@ -4,10 +4,15 @@ Django 4.0.4 release notes
 
 *April 11, 2022*
 
-Django 4.0.4 fixes two security issues with severity "high" and a bug in 4.0.3.
+Django 4.0.4 fixes two security issues with severity "high" and two bugs in
+4.0.3.
 
 Bugfixes
 ========
 
 * Fixed a regression in Django 4.0 that caused ignoring multiple
   ``FilteredRelation()`` relationships to the same field (:ticket:`33598`).
+
+* Fixed a regression in Django 3.2.4 that caused the auto-reloader to no longer
+  detect changes when the ``DIRS`` option of the ``TEMPLATES`` setting
+  contained an empty string (:ticket:`33628`).

tests/template_tests/test_autoreloader.py

@@ -68,6 +68,17 @@ class TemplateReloadTests(SimpleTestCase):
         autoreload.reset_loaders()
         self.assertEqual(mock_reset.call_count, 2)
 
+    @override_settings(
+        TEMPLATES=[
+            {
+                "DIRS": [""],
+                "BACKEND": "django.template.backends.django.DjangoTemplates",
+            }
+        ]
+    )
+    def test_template_dirs_ignore_empty_path(self):
+        self.assertEqual(autoreload.get_template_directories(), set())
+
     @override_settings(
         TEMPLATES=[
             {