pd panic if peer has no leader

[nietingbao]

pd/server/handler.go

Line 1050 in d82f4fa

IsLeader: peerID == region.GetLeader().Id,

version: v6.1.0

if TiKV cannot start and some region may lose leader , pd will panic during running. logs below are what we met in our env

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1bc477e]

goroutine 516 [running]:
github.com/tikv/pd/server.(*Handler).packHotRegions(0xc000691d10, 0x1a38d66?, {0x2708d13, 0x4})
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/pd/server/handler.go:1050 +0x37e
github.com/tikv/pd/server.(*Handler).PackHistoryHotReadRegions(0xc00470ee30?)
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/pd/server/handler.go:1005 +0x3e
github.com/tikv/pd/server/storage.(*HotRegionStorage).pullHotRegionInfo(0xc0002c7280)
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/pd/server/storage/hot_region_storage.go:258 +0x2e
github.com/tikv/pd/server/storage.(*HotRegionStorage).backgroundFlush(0xc0002c7280)
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/pd/server/storage/hot_region_storage.go:218 +0x195
created by github.com/tikv/pd/server/storage.NewHotRegionsStorage
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/pd/server/storage/hot_region_storage.go:159 +0x21b

[nietingbao]

/type bug

[rleungx]

seem #5330 accidentally fixes this problem.

[nietingbao]

seem #5330 accidentally fixes this problem.

thanks a lot