setgenerate true corrupts database on shutdown

[CaveSpectre11]

Reproduced on testnet (not reproduced on mainnet).

setgenerate true 1

Then stop your wallet; restarting it says chain is corrupt and needs to be resynched. Need to look into why.

[flyinghuman]

only in pow phase if you mine yourself blocks, else not.

[flyinghuman]

any solution for that?

[CaveSpectre11]

Not yet; The saved setup I had to reproduce the problem didn't actually do it, so I will need to re-setup the environment now that I have some sort of IDE to work (With Qt Creator) for investigation.

[CaveSpectre11]

Some chicken scratch in case I don't have this solved before I head out of town on vacation next week...

When mining; the last block being mined appears to be corrupt when the software comes back up; presumably because it wasn't written properly in the shutdown capture.

2019-06-26 23:32:27 CheckProofOfWork(): hash: d1a204254e8f43ddca90a8468eb3dbcaebf472bd5c66cb2139caee1d0fbe0a01, nbits: 1f22688b, bnTarget: 0022688b00000000000000000000000000000000000000000000000000000000
2019-06-26 23:32:27 ERROR: CheckProofOfWork() : hash doesn't match nBits
2019-06-26 23:32:27 ERROR: LoadBlockIndex() : CheckProofOfWork failed: CBlockIndex(pprev=0x7f61e0001680, nHeight=72, merkle=0000000000000000000000000000000000000000000000000000000000000000, hashBlock=d1a204254e8f43ddca90a8468eb3dbcaebf472bd5c66cb2139caee1d0fbe0a01)

After restarting and rebuilding the database; it returns to normal state. When shutting down (without setgenerate turned back on); the shutdown is clean.

More logs:

2019-06-26 23:55:42 proof-of-work found
  hash: 001d1213a8301fba17d1f5a6f34c31bfa8ed03db1f9533eb1d835424de762704
target: 0023c71f00000000000000000000000000000000000000000000000000000000
2019-06-26 23:55:42 CBlock(hash=001d1213a8301fba17d1f5a6f34c31bfa8ed03db1f9533eb1d835424de762704, ver=2, hashPrevBlock=010ecf2c1035039462afea44ccacf2a5cbd675d7ae3cbd43f94f2fccaf48521b, hashMerkleRoot=5dad6cd7dab89fd01111aa65cdda8a4e212871cb4ee3dbfc2b57cdeea23f2e78, nTime=1561593342, nBits=1f23c71f, nNonce=2355, vtx=1)
  CTransaction(hash=5dad6cd7da, ver=1, vin.size=1, vout.size=3, nLockTime=0)
    CTxIn(COutPoint(0000000000000000000000000000000000000000000000000000000000000000, 4294967295), coinbase 01640101)
    CTxOut(nValue=0.90000000, scriptPubKey=02b4c3395886ffe1f75a3784eba64e)
    CTxOut(nValue=0.03000000, scriptPubKey=0329b41789e8fd75dc7168d05dec32)
    CTxOut(nValue=0.07000000, scriptPubKey=031f3b25791150d4243608c51f39c1)

  vMerkleTree:  5dad6cd7dab89fd01111aa65cdda8a4e212871cb4ee3dbfc2b57cdeea23f2e78

2019-06-26 23:55:42 generated 0.90
2019-06-26 23:55:42 Verifying mncache.dat format...
2019-06-26 23:55:42 Loaded info from mncache.dat  1ms
2019-06-26 23:55:42   Masternodes: 0, peers who asked us for Masternode list: 0, peers we asked for Masternode list: 5, entries in Masternode list we asked for: 1, nDsqCount: 0
2019-06-26 23:55:42 Writing info to mncache.dat...
2019-06-26 23:55:42 Written info to mncache.dat  1ms
2019-06-26 23:55:42   Masternodes: 0, peers who asked us for Masternode list: 0, peers we asked for Masternode list: 5, entries in Masternode list we asked for: 3, nDsqCount: 0
2019-06-26 23:55:42 Masternode dump finished  4ms
2019-06-26 23:55:42 keypool keep 101
2019-06-26 23:55:42 ThreadBitcoinMiner() exceptionThreadBitcoinMiner exiting
2019-06-26 23:55:42 Shutdown: done

Startup

2019-06-26 23:55:57 CheckProofOfWork(): hash: 09eb3d2306443e78d190dd5afb307b2063e7da27835696e0617830b6abd59208, nbits: 2000e0cd, bnTarget: 00e0cd0000000000000000000000000000000000000000000000000000000000
2019-06-26 23:55:57 ERROR: CheckProofOfWork() : hash doesn't match nBits
2019-06-26 23:55:57 ERROR: LoadBlockIndex() : CheckProofOfWork failed: CBlockIndex(pprev=0x55954ba43ac0, nHeight=98, merkle=0000000000000000000000000000000000000000000000000000000000000000, hashBlock=09eb3d2306443e78d190dd5afb307b2063e7da27835696e0617830b6abd59208)
2019-06-26 23:55:57 : Error loading block database.

More logs:
Startup marks the following

2019-06-26 23:55:57 CheckProofOfWork(): hash: 09eb3d2306443e78d190dd5afb307b2063e7da27835696e0617830b6abd59208, nbits: 2000e0cd, bnTarget: 00e0cd0000000000000000000000000000000000000000000000000000000000
2019-06-26 23:55:57 ERROR: CheckProofOfWork() : hash doesn't match nBits
2019-06-26 23:55:57 ERROR: LoadBlockIndex() : CheckProofOfWork failed: CBlockIndex(pprev=0x55954ba43ac0, nHeight=98, merkle=0000000000000000000000000000000000000000000000000000000000000000, hashBlock=09eb3d2306443e78d190dd5afb307b2063e7da27835696e0617830b6abd59208)

But looking back to block 98

2019-06-26 23:55:41 CreateNewBlock(): total size 1000
2019-06-26 23:55:41 Running UCCMiner with 1 transactions in block (268 bytes)
2019-06-26 23:55:41 BitcoinMiner:
2019-06-26 23:55:41 proof-of-work found
  hash: 0085a555dadc75ca5724b8af5a9a8d8910d0d2379282572961380fb6bf705808
target: 00e0cd0000000000000000000000000000000000000000000000000000000000
2019-06-26 23:55:41 CBlock(hash=0085a555dadc75ca5724b8af5a9a8d8910d0d2379282572961380fb6bf705808, ver=2, hashPrevBlock=00061486a7eee527655574e72a2c9368d75e59921018ccd6653a60253824805b, hashMerkleRoot=372fd8e3e63dd6c7e602954c1c979a18170759a160630495d25a921f49544b66, nTime=1561593341, nBits=2000e0cd, nNonce=68, vtx=1)
  CTransaction(hash=372fd8e3e6, ver=1, vin.size=1, vout.size=3, nLockTime=0)
    CTxIn(COutPoint(0000000000000000000000000000000000000000000000000000000000000000, 4294967295), coinbase 01620101)
    CTxOut(nValue=0.90000000, scriptPubKey=0378098c3deabd3b0924f1c00ebf1c)
    CTxOut(nValue=0.03000000, scriptPubKey=0329b41789e8fd75dc7168d05dec32)
    CTxOut(nValue=0.07000000, scriptPubKey=031f3b25791150d4243608c51f39c1)

  vMerkleTree:  372fd8e3e63dd6c7e602954c1c979a18170759a160630495d25a921f49544b66

2019-06-26 23:55:41 generated 0.90
2019-06-26 23:55:41 keypool keep 99
2019-06-26 23:55:41 UpdateTip: new best=0085a555dadc75ca5724b8af5a9a8d8910d0d2379282572961380fb6bf705808  height=98  log2_work=20.299344  tx=99  date=2019-06-26 23:55:41 progress=1.000000  cache=19
2019-06-26 23:55:41 AddToWallet 372fd8e3e63dd6c7e602954c1c979a18170759a160630495d25a921f49544b66  new

nbits and target matched; but the hash definitely got wonked up.

[CaveSpectre11]

The corruption is detected in bool CBlockTreeDB::LoadBlockIndexGuts(); where it finds a bad block hash:

2019-06-27 01:55:32 loading 84:
        blck: 2f7b87e1b69828561c0a1e1e76a7fbdf6875e7499fdb781fa7546049930b4613
        hash: null
        prev: 0001879cca6b84bdf6dd5248280608082bfe778721672c9046491a6ba313a370
        next: 0000000000000000000000000000000000000000000000000000000000000000
2019-06-27 01:55:32 CheckProofOfWork(): hash: 2f7b87e1b69828561c0a1e1e76a7fbdf6875e7499fdb781fa7546049930b4613, nbits: 1f035a7f, bnTarget: 00035a7f00000000000000000000000000000000000000000000000000000000
2019-06-27 01:55:32 ERROR: CheckProofOfWork() : hash doesn't match nBits

In the above; it shouldn't have been 2f7b87e1b69828561c0a1e1e76a7fbdf6875e7499fdb781fa7546049930b4613; so it's wrong in the database. I need to go through the write and see if there's a way to prevent it from writing, or complete the correct writing, during a shutdown... or otherwise find where it's being written incorrectly...

... or figure out a way to throw it away and go load the block from the network instead.

The first option prevents this problem. The second option begins a path down a road I want to go on eventually... removing the corruptions when wallets crash, so you don't have to reindex or load from a bootstrap if your don't get your wallet shut down cleanly.

[neoncoin-project]

Any updates @CaveSpectre11 ? Im working on a project and the same happends, when i shutdown the wallet when setgenerate is running, the database corrupts.

[flyinghuman]

as we don't need setgenerate anymore because we are in POS State we did ignore this Problem @neoncoin-tech - but yes, this is annoying and it would be good to have it fixed.