apicodec: do not decode empty key for codec v2 (#1734)

 

Signed-off-by: tangenta <[email protected]>

Author: tangenta

internal/apicodec/codec_v2.go

@@ -13,6 +13,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/tikv/client-go/v2/internal/logutil"
 	"github.com/tikv/client-go/v2/tikvrpc"
+	"github.com/tikv/client-go/v2/util/intest"
 	"github.com/tikv/client-go/v2/util/redact"
 	"go.uber.org/zap"
 )
@@ -705,6 +706,14 @@ func (c *codecV2) EncodeKey(key []byte) []byte {
 }
 
 func (c *codecV2) DecodeKey(encodedKey []byte) ([]byte, error) {
+	if len(encodedKey) == 0 {
+		if !intest.InTest {
+			logutil.BgLogger().Warn(
+				"codecV2.DecodeKey called with empty key. This shouldn't happen in prod",
+				zap.Stack("stack"))
+		}
+		return nil, nil
+	}
 	// If the given key does not start with the correct prefix,
 	// return out of bound error.
 	if !bytes.HasPrefix(encodedKey, c.prefix) {

util/intest/in_unittest.go

@@ -0,0 +1,20 @@
+// Copyright 2025 TiKV Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build intest
+
+package intest
+
+// InTest checks if the code is running in test.
+var InTest = true

util/intest/not_in_unittest.go

@@ -0,0 +1,20 @@
+// Copyright 2025 TiKV Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !intest
+
+package intest
+
+// InTest checks if the code is running in test.
+var InTest = false