Update checks.py (#10462)

Prevent "RemovedInDjango51Warning: The DEFAULT_FILE_STORAGE setting is deprecated. Use STORAGES instead."

CHANGELOG.txt

@@ -4,6 +4,7 @@ Changelog
 5.3 (xx.xx.xxxx) - IN DEVELOPMENT
 ~~~~~~~~~~~~~~~~
 
+ * Fix: Update system check for overwriting storage backends to recognise the `STORAGES` setting introduced in Django 4.2 (phijma-leukeleu)
  * Maintenance: Update BeautifulSoup upper bound to 4.12.x (scott-8)
 
 

CONTRIBUTORS.md

@@ -754,6 +754,7 @@
 * Meghana Reddy
 * Chinedu Ihedioha
 * scott-8
+* phijma-leukeleu
 
 ## Translators
 

docs/releases/5.3.md

@@ -18,7 +18,7 @@ depth: 1
 
 ### Bug fixes
 
- * ...
+ * Update system check for overwriting storage backends to recognise the `STORAGES` setting introduced in Django 4.2 (phijma-leukeleu)
 
 ### Documentation
 

wagtail/admin/checks.py

@@ -188,8 +188,17 @@ def wagtail_admin_base_url_check(app_configs, **kwargs):
 @register("file_overwrite")
 def file_overwrite_check(app_configs, **kwargs):
     from django.conf import settings
+    from django import VERSION as DJANGO_VERSION
 
-    file_storage = getattr(settings, "DEFAULT_FILE_STORAGE", None)
+    if DJANGO_VERSION >= (5, 1):
+        file_storage = getattr(settings, "STORAGES")["default"]["BACKEND"]
+    elif DJANGO_VERSION >= (4, 2):
+        try:
+            file_storage = getattr(settings, "STORAGES")["default"]["BACKEND"]
+        except AttributeError:
+            file_storage = getattr(settings, "DEFAULT_FILE_STORAGE", None)
+    else:
+        file_storage = getattr(settings, "DEFAULT_FILE_STORAGE", None)
 
     errors = []