test: cover metadata reload with equal maximum timestamps

Signed-off-by: Feng Ruohang <rh@vonng.com>

cmd/bucket-metadata-reload_test.go

@@ -0,0 +1,54 @@
+// Copyright 2026 PGSTY contributors.
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+package cmd
+
+import (
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/minio/minio/internal/auth"
+	"github.com/minio/minio/internal/grid"
+)
+
+func TestPeerMetadataReloadWithEqualMaximumTimestamp(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{t: t, objAPITest: testPeerMetadataReloadWithEqualMaximumTimestamp})
+}
+
+func testPeerMetadataReloadWithEqualMaximumTimestamp(obj ObjectLayer, instanceType, bucket string, _ http.Handler, _ auth.Credentials, t *testing.T) {
+	disk, err := loadBucketMetadata(t.Context(), obj, bucket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	disk.TaggingConfigXML = []byte(`<Tagging><TagSet><Tag><Key>revision</Key><Value>new</Value></Tag></TagSet></Tagging>`)
+	disk.TaggingConfigUpdatedAt = UTCNow()
+	// An unrelated configuration has the greatest timestamp in both records.
+	disk.PolicyConfigUpdatedAt = disk.TaggingConfigUpdatedAt.Add(time.Hour)
+	if err := disk.Save(t.Context(), obj); err != nil {
+		t.Fatal(err)
+	}
+	resident := disk
+	resident.TaggingConfigXML = []byte(`<Tagging><TagSet><Tag><Key>revision</Key><Value>old</Value></Tag></TagSet></Tagging>`)
+	resident.TaggingConfigUpdatedAt = disk.TaggingConfigUpdatedAt.Add(-time.Minute)
+	if err := resident.parseAllConfigs(t.Context(), obj); err != nil {
+		t.Fatal(err)
+	}
+	if !resident.lastUpdate().Equal(disk.lastUpdate()) {
+		t.Fatal("fixture must have equal maximum timestamps")
+	}
+	globalBucketMetadataSys.Set(bucket, resident)
+
+	args := grid.MSS{peerRESTBucket: bucket}
+	if _, err := (&peerRESTServer{}).LoadBucketMetadataHandler(&args); err != nil {
+		t.Fatal(err)
+	}
+	tagging, _, err := globalBucketMetadataSys.GetTaggingConfig(bucket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := tagging.ToMap()["revision"]; got != "new" {
+		t.Errorf("%s: peer reload retained tag %q despite a newer tagging configuration", instanceType, got)
+	}
+}