节点运行过程中出现panic

[AndreaHan]

环境：Alaya链
问题：Alaya节点运行时出现panic，这是什么panic
部分日志：
`DEBUG[07-21|09:09:21.950|consensus/cbft/network/router.go:205] consensusNodes in kMixingRandomNodes cNodes=25 ids=c45a914bba5ad5c7,6f5584a27a272099,00aa2e361168765c,fff1010bbf1762d1,ed552a64f708696a,9460fce5beea98e4,ab74f5500dd35497,a71e63927d7c9642,14c2b76bd5945f8f,205e875111a1b576,a2340b4acd4f7b74,505ef930162c1b07,87aa41f5f3ae9626,680b23be9f9b1fa7,d0f648262b54c16a,32d622ecfc31deaa,656e0ee96374d3f6,a138433f1bc37e0c,c0dc97ee57ba202f,8bc8734315acf2af,e504fb1ed169c96d,73686446756b8345,1fd9fd7d9c31dad1,0eb6b43a9945a062,3581081a17b98c9b
DEBUG[07-21|09:09:21.950|consensus/cbft/network/handler.go:731] Request missing viewchange failed err="no need sync viewchange"
DEBUG[07-21|09:09:21.951|consensus/cbft/sync_process.go:692] MissingPrepareVote epoch=89047 view=6 epoch=89047 viewNumber=6 beginIndex=7 endIndex=9 validatorLen=25
DEBUG[07-21|09:09:21.951|consensus/cbft/sync_process.go:699] The length of prepare vote epoch=89047 view=6 index=7 size=25
DEBUG[07-21|09:09:21.951|consensus/cbft/sync_process.go:699] The length of prepare vote epoch=89047 view=6 index=8 size=22
DEBUG[07-21|09:09:21.951|consensus/cbft/network/handler.go:709] Request missing prepareVote failed err="not need sync prepare vote"
DEBUG[07-21|09:09:21.951|consensus/cbft/network/router.go:233] kMixingRandomNodes select node msgHash=99a3d9…a6a0e3 cNodesLen=25 ncNodesLen=46 peerSetLen=50
DEBUG[07-21|09:09:21.951|consensus/cbft/network/router.go:110] Gossip message msgHash=99a3d9…a6a0e3 msgType=*protocols.PrepareVote msg={Epoch:89047,ViewNumber:6,Hash:20f2b8…59e8d6,Number:22261569,BlockIndex:8,ValidatorIndex:14} targetPeer=ed552a64f708696a,9460fce5beea98e4,205e875111a1b576,7dc831a166882750,e3c84ebcd351010d,ae75f869ed4d8bf8,3015687818ccdeac,218b20ee9cd80ea6
DEBUG[07-21|09:09:21.960|eth/handler.go:729] Received a message[NewBlockHashesMsg]------------ receiveAt=1626858561 peerId=fad7c5a4d4fef670 hash=0eeee5…fe9d7c number=22261567
DEBUG[07-21|09:09:21.993|eth/handler.go:729] Received a message[NewBlockHashesMsg]------------ receiveAt=1626858561 peerId=3fdefc6e19e46cb0 hash=1fa089…13c0f1 number=22261566
DEBUG[07-21|09:09:22.078|internal/ethapi/api.go:659] Executing VM call finished runtime=85.557µs
ERROR[07-21|09:09:22.078|rpc/server.go:134] goroutine 196934206 [running]:
github.com/PlatONnetwork/PlatON-Go/rpc.(*Server).serveRequest.func1(0xc0132392f0, 0x1758260, 0xc058df5d10)
/opt/jenkins/workspace/PlatON/build_ubuntu/rpc/server.go:133 +0x123
panic(0x12fb020, 0x21f64e0)
/usr/lib/go-1.13/src/runtime/panic.go:679 +0x1b2
github.com/PlatONnetwork/PlatON-Go/core.(*ExecutionResult).Return(...)
/opt/jenkins/workspace/PlatON/build_ubuntu/core/state_transition.go:97
github.com/PlatONnetwork/PlatON-Go/internal/ethapi.(*PublicBlockChainAPI).Call(0xc00dcf3120, 0x174ae60, 0xc02ba297c0, 0x0, 0x0, 0x0, 0xc070be8b20, 0x0, 0x0, 0x0, ...)
/opt/jenkins/workspace/PlatON/build_ubuntu/internal/ethapi/api.go:735 +0xbd
reflect.Value.call(0xc000178b00, 0xc0000c5488, 0x13, 0x148b63b, 0x4, 0xc03b79cc00, 0x4, 0x4, 0x4, 0x30, ...)
/usr/lib/go-1.13/src/reflect/value.go:460 +0x5f6
reflect.Value.Call(0xc000178b00, 0xc0000c5488, 0x13, 0xc03b79cc00, 0x4, 0x4, 0x2, 0x2, 0x2)
/usr/lib/go-1.13/src/reflect/value.go:321 +0xb4
github.com/PlatONnetwork/PlatON-Go/rpc.(*Server).handle(0xc0132392f0, 0x174ae60, 0xc02ba297c0, 0x1758260, 0xc058df5d10, 0xc03b79cb40, 0xc058df5d80, 0x0, 0x12e8e80)
/opt/jenkins/workspace/PlatON/build_ubuntu/rpc/server.go:310 +0x6b0
github.com/PlatONnetwork/PlatON-Go/rpc.(*Server).exec(0xc0132392f0, 0x174ae60, 0xc02ba297c0, 0x1758260, 0xc058df5d10, 0xc03b79cb40)
/opt/jenkins/workspace/PlatON/build_ubuntu/rpc/server.go:345 +0x1c4
github.com/PlatONnetwork/PlatON-Go/rpc.(*Server).serveRequest(0xc0132392f0, 0x174af20, 0xc07b7e41e0, 0x1758260, 0xc058df5d10, 0xc059fa4701, 0x1, 0x0, 0x0)
/opt/jenkins/workspace/PlatON/build_ubuntu/rpc/server.go:193 +0x3ff
github.com/PlatONnetwork/PlatON-Go/rpc.(*Server).ServeSingleRequest(...)
/opt/jenkins/workspace/PlatON/build_ubuntu/rpc/server.go:224
github.com/PlatONnetwork/PlatON-Go/rpc.(*Server).ServeHTTP(0xc0132392f0, 0x1744660, 0xc020fe3420, 0xc075f76c00)
/opt/jenkins/workspace/PlatON/build_ubuntu/rpc/http.go:252 +0x4f7
github.com/PlatONnetwork/PlatON-Go/rpc.(*virtualHostHandler).ServeHTTP(0xc01335cb40, 0x1744660, 0xc020fe3420, 0xc075f76c00)
/opt/jenkins/workspace/PlatON/build_ubuntu/rpc/http.go:319 +0x200
net/http.serverHandler.ServeHTTP(0xc013304c40, 0x1744660, 0xc020fe3420, 0xc075f76c00)
/usr/lib/go-1.13/src/net/http/server.go:2802 +0xa4
net/http.(*conn).serve(0xc07aaa4960, 0x174ae60, 0xc02ba295c0)
/usr/lib/go-1.13/src/net/http/server.go:1890 +0x875
created by net/http.(*Server).Serve
/usr/lib/go-1.13/src/net/http/server.go:2927 +0x38e

DEBUG[07-21|09:09:22.082|consensus/cbft/cbft.go:342] Received message from peer epoch=89047 view=6 peer=d2f55bc09c256d78 type=*protocols.PrepareVote msgHash=0a2bbc…2833fb BHash=20f2b8…59e8d6 msg={peer:d2f55bc09c256d78,type:*protocols.PrepareVote,msg:{Epoch:89047,ViewNumber:6,Hash:20f2b8…59e8d6,Number:22261569,BlockIndex:8,ValidatorIndex:0}} peerMsgCh=0
DEBUG[07-21|09:09:22.082|consensus/cbft/consensus_process.go:108] Receive PrepareVote epoch=89047 view=6 id=d2f55bc09c256d78 msg={Epoch:89047,ViewNumber:6,Hash:20f2b8…59e8d6,Number:22261569,BlockIndex:8,ValidatorIndex:0}`

[junjiequ123]

this issue raised relatively good, with panic in title as keyword. Node panic.
Need more explaination of WHEN this happen, after running for XXXX blocks, or shortly after fresh start?

[benbaley]

fixed in #95