From 6062f296034aba72bdcf29ba55812d025d6faeeb Mon Sep 17 00:00:00 2001
From: yifan <xuyifan02@pingcap.com>
Date: Tue, 15 Jun 2021 22:31:58 +0800
Subject: [PATCH] fix null pointer

---
 util/logutil/log.go | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/util/logutil/log.go b/util/logutil/log.go
index 1a7b41ade9208..d99227e364e77 100644
--- a/util/logutil/log.go
+++ b/util/logutil/log.go
@@ -142,7 +142,7 @@ func initGRPCLogger(cfg *LogConfig) error {
 }
 
 func deepcopyLogConfig(o *log.Config) *log.Config {
-	return &log.Config{
+	c := &log.Config{
 		Level:            o.Level,
 		Format:           o.Format,
 		DisableTimestamp: o.DisableTimestamp,
@@ -156,12 +156,15 @@ func deepcopyLogConfig(o *log.Config) *log.Config {
 		DisableCaller:       o.DisableCaller,
 		DisableStacktrace:   o.DisableStacktrace,
 		DisableErrorVerbose: o.DisableErrorVerbose,
-		Sampling: &zap.SamplingConfig{
+	}
+	if o.Sampling != nil {
+		c.Sampling = &zap.SamplingConfig{
 			Initial:    o.Sampling.Initial,
 			Thereafter: o.Sampling.Thereafter,
 			Hook:       o.Sampling.Hook,
-		},
+		}
 	}
+	return c
 }
 
 // InitZapLogger is delegated to InitLogger.