From a7d9afd61bb36ed7bc9cd3b13a594db32c1f3cec Mon Sep 17 00:00:00 2001
From: Mahmoud Hashemi <mahmoud@hatnote.com>
Date: Sun, 2 Feb 2025 21:38:50 -0800
Subject: [PATCH] add fsync to atomic_save for correctness

---
 boltons/fileutils.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/boltons/fileutils.py b/boltons/fileutils.py
index 18c66567..2a057704 100644
--- a/boltons/fileutils.py
+++ b/boltons/fileutils.py
@@ -465,6 +465,9 @@ def __enter__(self):
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         if self.part_file:
+            # Ensure data is flushed and synced to disk before closing
+            self.part_file.flush()
+            os.fsync(self.part_file.fileno())
             self.part_file.close()
         if exc_type:
             if self.rm_part_on_exc: