From 401cc1a5753ea04060f7a6299d517046f50f6885 Mon Sep 17 00:00:00 2001
From: lixd <xueduan.li@gmail.com>
Date: Sat, 15 Jan 2022 13:16:44 +0800
Subject: [PATCH 1/3] mvcc: add a fast return at put method

return when two leaseID is equal, avoid invalid operations.

Fixes #13600
---
 server/storage/mvcc/kvstore_txn.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/server/storage/mvcc/kvstore_txn.go b/server/storage/mvcc/kvstore_txn.go
index 56c2335c2..ab04bcf5f 100644
--- a/server/storage/mvcc/kvstore_txn.go
+++ b/server/storage/mvcc/kvstore_txn.go
@@ -220,6 +220,11 @@ func (tw *storeTxnWrite) put(key, value []byte, leaseID lease.LeaseID) {
 	tw.changes = append(tw.changes, kv)
 	tw.trace.Step("store kv pair into bolt db")
 
+	if oldLease == leaseID {
+		tw.trace.Step("attach lease to kv pair")
+		return
+	}
+
 	if oldLease != lease.NoLease {
 		if tw.s.le == nil {
 			panic("no lessor to detach lease")

From 1d706179be981e025ca8f510ca3978644c9f92eb Mon Sep 17 00:00:00 2001
From: lixd <xueduan.li@gmail.com>
Date: Sun, 16 Jan 2022 10:43:15 +0800
Subject: [PATCH 2/3] mvcc: add test-case

a test-case for new code-path.
---
 server/storage/mvcc/kv_test.go | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/server/storage/mvcc/kv_test.go b/server/storage/mvcc/kv_test.go
index f2be7f904..a4e13d693 100644
--- a/server/storage/mvcc/kv_test.go
+++ b/server/storage/mvcc/kv_test.go
@@ -360,6 +360,40 @@ func testKVDeleteMultipleTimes(t *testing.T, f deleteRangeFunc) {
 	}
 }
 
+func TestKVPutWithSameLease(t *testing.T)    { testKVPutWithSameLease(t, normalPutFunc) }
+func TestKVTxnPutWithSameLease(t *testing.T) { testKVPutWithSameLease(t, txnPutFunc) }
+
+func testKVPutWithSameLease(t *testing.T, f putFunc) {
+	b, tmpPath := betesting.NewDefaultTmpBackend(t)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, StoreConfig{})
+	defer cleanup(s, b, tmpPath)
+	leaseID := int64(1)
+
+	// put foo
+	rev := f(s, []byte("foo"), []byte("bar"), lease.LeaseID(leaseID))
+	if rev != 2 {
+		t.Errorf("rev = %d, want %d", 2, rev)
+	}
+
+	// put foo with same lease again
+	rev2 := f(s, []byte("foo"), []byte("bar"), lease.LeaseID(leaseID))
+	if rev2 != 3 {
+		t.Errorf("rev = %d, want %d", 3, rev2)
+	}
+
+	// check leaseID
+	r, err := s.Range(context.TODO(), []byte("foo"), nil, RangeOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	wkvs := []mvccpb.KeyValue{
+		{Key: []byte("foo"), Value: []byte("bar"), CreateRevision: 2, ModRevision: 3, Version: 2, Lease: leaseID},
+	}
+	if !reflect.DeepEqual(r.KVs, wkvs) {
+		t.Errorf("kvs = %+v, want %+v", r.KVs, wkvs)
+	}
+}
+
 // test that range, put, delete on single key in sequence repeatedly works correctly.
 func TestKVOperationInSequence(t *testing.T) {
 	b, tmpPath := betesting.NewDefaultTmpBackend(t)