[1.10.x] Fixed #26896 -- Allowed a lazy base_url for FileSystemStorage.

Backport of b820b6108a7d3f11ec18774d16d657f4f63fe9fa from master

1 files changed, 2 insertions, 2 deletions

diff --git a/django/core/files/storage.py b/django/core/files/storage.py
index b5348948fe..c3ad1faadf 100644
--- a/django/core/files/storage.py
+++ b/django/core/files/storage.py
@@ -254,8 +254,6 @@ class FileSystemStorage(Storage):
     def __init__(self, location=None, base_url=None, file_permissions_mode=None,
                  directory_permissions_mode=None):
         self._location = location
-        if base_url is not None and not base_url.endswith('/'):
-            base_url += '/'
         self._base_url = base_url
         self._file_permissions_mode = file_permissions_mode
         self._directory_permissions_mode = directory_permissions_mode
@@ -286,6 +284,8 @@ class FileSystemStorage(Storage):
 
     @cached_property
     def base_url(self):
+        if self._base_url is not None and not self._base_url.endswith('/'):
+            self._base_url += '/'
         return self._value_or_setting(self._base_url, settings.MEDIA_URL)
 
     @cached_property