kvcoord: fix QueryLocks and LeaseInfo handling in txnWriteBuffer

This commit fixes an oversight in how we handled QueryLocks and
LeaseInfo requests in the txnWriteBuffer. We simply pass the request and
the response through, but we forgot to properly propagate the response
out. The bug was exposed in a recent refactor
65476fc.

Release note: None

Author: yuzefovich

pkg/kv/kvclient/kvcoord/txn_interceptor_write_buffer.go

@@ -1168,11 +1168,18 @@ func (rr requestRecord) toResp(
 	case *kvpb.QueryLocksRequest, *kvpb.LeaseInfoRequest:
 		// These requests don't interact with buffered writes, so we simply
 		// let the response through unchanged.
+		ru = br
 
 	default:
 		return ru, kvpb.NewError(unsupportedMethodError(req.Method()))
 	}
 
+	if buildutil.CrdbTestBuild {
+		if ru.GetInner() == nil {
+			panic(errors.AssertionFailedf("expected response to be set for type %T", rr.origRequest))
+		}
+	}
+
 	return ru, nil
 }
 

pkg/kv/kvclient/kvcoord/txn_interceptor_write_buffer_test.go

@@ -270,15 +270,21 @@ func TestTxnWriteBufferBlindWritesIncludingOtherRequests(t *testing.T) {
 	getB := &kvpb.GetRequest{RequestHeader: kvpb.RequestHeader{Key: keyB}}
 	delC := delArgs(keyC, txn.Sequence)
 	scanDE := &kvpb.ScanRequest{RequestHeader: kvpb.RequestHeader{Key: keyD, EndKey: keyE}}
+	queryLocks := &kvpb.QueryLocksRequest{RequestHeader: kvpb.RequestHeader{Key: keyA, EndKey: keyE}, IncludeUncontended: true}
+	leaseInfo := &kvpb.LeaseInfoRequest{}
 	ba.Add(putA)
 	ba.Add(getB)
 	ba.Add(delC)
 	ba.Add(scanDE)
+	ba.Add(queryLocks)
+	ba.Add(leaseInfo)
 
 	mockSender.MockSend(func(ba *kvpb.BatchRequest) (*kvpb.BatchResponse, *kvpb.Error) {
-		require.Len(t, ba.Requests, 2)
+		require.Len(t, ba.Requests, 4)
 		require.IsType(t, &kvpb.GetRequest{}, ba.Requests[0].GetInner())
 		require.IsType(t, &kvpb.ScanRequest{}, ba.Requests[1].GetInner())
+		require.IsType(t, &kvpb.QueryLocksRequest{}, ba.Requests[2].GetInner())
+		require.IsType(t, &kvpb.LeaseInfoRequest{}, ba.Requests[3].GetInner())
 
 		br := ba.CreateReply()
 		br.Txn = ba.Txn
@@ -289,13 +295,15 @@ func TestTxnWriteBufferBlindWritesIncludingOtherRequests(t *testing.T) {
 	require.Nil(t, pErr)
 	require.NotNil(t, br)
 
-	// Expect 4 responses, even though only 2 KV requests were sent. Moreover,
-	// ensure that the responses are in the correct order.
-	require.Len(t, br.Responses, 4)
+	// Expect 6 responses, even though only 4 KV requests were sent. Moreover,
+	// ensure that the responses are in the correct order and non-nil.
+	require.Len(t, br.Responses, 6)
 	require.IsType(t, &kvpb.PutResponse{}, br.Responses[0].GetInner())
 	require.IsType(t, &kvpb.GetResponse{}, br.Responses[1].GetInner())
 	require.IsType(t, &kvpb.DeleteResponse{}, br.Responses[2].GetInner())
 	require.IsType(t, &kvpb.ScanResponse{}, br.Responses[3].GetInner())
+	require.IsType(t, &kvpb.QueryLocksResponse{}, br.Responses[4].GetInner())
+	require.IsType(t, &kvpb.LeaseInfoResponse{}, br.Responses[5].GetInner())
 
 	// Verify the writes were buffered correctly.
 	expBufferedWrites := []bufferedWrite{