From 0a39aa4d326153bc10c64ef675be93cd18536ad7 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Mon, 13 Jul 2026 13:53:29 +0100
Subject: [PATCH] hdfs: fix incorrect modtime after uploading a file or setting
 its modtime

SetModTime (which Put and Update also use) kept the caller's full
precision modtime in memory while Chtimes sets it with second
precision, so until the object was re-read the modtime did not match
what a fresh listing would report. This broke wrappers which compare
exact modtimes, such as the hasher backend's fingerprint and the VFS
cache. Truncate the modtime to second precision to match what the
server stores.
---
 backend/hdfs/object.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/backend/hdfs/object.go b/backend/hdfs/object.go
index d6d25297f..688e663ea 100644
--- a/backend/hdfs/object.go
+++ b/backend/hdfs/object.go
@@ -50,7 +50,10 @@ func (o *Object) SetModTime(ctx context.Context, modTime time.Time) error {
 	if err != nil {
 		return err
 	}
-	o.modTime = modTime
+	// Chtimes sets the modtime with second precision so truncate
+	// here too to keep the in-memory modtime identical to the one a
+	// fresh listing returns.
+	o.modTime = modTime.Truncate(time.Second)
 	return nil
 }