Fixed #35326 -- handled temporary uploaded files for OverwritingStorage.

django/core/files/storage/filesystem.py

@@ -21,9 +21,7 @@ class FileSystemStorage(Storage, StorageSettingsMixin):
     Standard filesystem storage
     """
 
-    # The combination of O_CREAT and O_EXCL makes os.open() raise OSError if
-    # the file already exists before it's opened.
-    OS_OPEN_FLAGS = os.O_WRONLY | os.O_CREAT | os.O_EXCL | getattr(os, "O_BINARY", 0)
+    ALLOW_OVERWRITE = False
 
     def __init__(
         self,
@@ -98,12 +96,18 @@ def _save(self, name, content):
             try:
                 # This file has a file path that we can move.
                 if hasattr(content, "temporary_file_path"):
-                    file_move_safe(content.temporary_file_path(), full_path)
+                    file_move_safe(
+                        content.temporary_file_path(),
+                        full_path,
+                        allow_overwrite=self.ALLOW_OVERWRITE,
+                    )
 
                 # This is a normal uploadedfile that we can stream.
                 else:
-                    # The current umask value is masked out by os.open!
-                    fd = os.open(full_path, self.OS_OPEN_FLAGS, 0o666)
+                    open_flags = os.O_WRONLY | os.O_CREAT | getattr(os, "O_BINARY", 0)
+                    if not self.ALLOW_OVERWRITE:
+                        open_flags |= os.O_EXCL
+                    fd = os.open(full_path, open_flags, 0o666)
                     _file = None
                     try:
                         locks.lock(fd, locks.LOCK_EX)

tests/file_storage/tests.py

@@ -613,8 +613,7 @@ class OverwritingStorage(FileSystemStorage):
     unused name.
     """
 
-    # Mask out O_EXCL so os.open() doesn't raise OSError if the file exists.
-    OS_OPEN_FLAGS = FileSystemStorage.OS_OPEN_FLAGS & ~os.O_EXCL
+    ALLOW_OVERWRITE = True
 
     def get_available_name(self, name, max_length=None):
         """Override the effort to find an used name."""
@@ -648,6 +647,34 @@ def test_save_overwrite_behavior(self):
         finally:
             self.storage.delete(name)
 
+    def test_save_overwrite_behavior_temp_file(self):
+        """Saving to same file name twice overwrites the first file."""
+        name = "test.file"
+        self.assertFalse(self.storage.exists(name))
+        content_1 = b"content one"
+        content_2 = b"second content"
+        f_1 = TemporaryUploadedFile("tmp1", "text/plain", 11, "utf8")
+        f_1.write(content_1)
+        f_1.seek(0)
+        f_2 = TemporaryUploadedFile("tmp2", "text/plain", 14, "utf8")
+        f_2.write(content_2)
+        f_2.seek(0)
+        stored_name_1 = self.storage.save(name, f_1)
+        try:
+            self.assertEqual(stored_name_1, name)
+            self.assertTrue(self.storage.exists(name))
+            self.assertTrue(os.path.exists(os.path.join(self.temp_dir, name)))
+            with self.storage.open(name) as fp:
+                self.assertEqual(fp.read(), content_1)
+            stored_name_2 = self.storage.save(name, f_2)
+            self.assertEqual(stored_name_2, name)
+            self.assertTrue(self.storage.exists(name))
+            self.assertTrue(os.path.exists(os.path.join(self.temp_dir, name)))
+            with self.storage.open(name) as fp:
+                self.assertEqual(fp.read(), content_2)
+        finally:
+            self.storage.delete(name)
+
 
 class DiscardingFalseContentStorage(FileSystemStorage):
     def _save(self, name, content):