I get a lot of spurious messages like this in the log:
```
2019-08-31T18:07:53Z Synchronizing blockheaders, height: 592633 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
```
also
```
2019-08-31T18:19:47Z New outbound peer connected: version: 70015, blocks=592636, peer=0
2019-08-31T18:19:47Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:19:47Z New outbound peer connected: version: 70015, blocks=592636, peer=1
2019-08-31T18:19:48Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:19:48Z New outbound peer connected: version: 70015, blocks=592636, peer=2
2019-08-31T18:19:49Z Synchronizing blockheaders, height: 592636 (~100.00%)
```
This log message was introduced in #15615 by @jonasschnelli..
From what I understand, it's supposed to only be shown once per 2000 blocks, not multiple times for the same block.


assert(!(pindex->nStatus & BLOCK_HAVE_DATA) == (pindex->nTx == 0));
            assert(pindexFirstMissing == pindexFirstNeverProcessed);
        } else {
            
            if (pindex->nStatus & BLOCK_HAVE_DATA) assert(pindex->nTx > 0);
        }
        if (pindex->nStatus & BLOCK_HAVE_UNDO) assert(pindex->nStatus & BLOCK_HAVE_DATA);
        assert(((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TRANSACTIONS) == (pindex->nTx > 0)); 
        
        assert((pindexFirstNeverProcessed == nullptr) == pindex->HaveTxsDownloaded());
        assert((pindexFirstNotTransactionsValid == nullptr) == pindex->HaveTxsDownloaded());
        assert(pindex->nHeight == nHeight); 
        assert(pindex->pprev == nullptr || pindex->nChainWork >= pindex->pprev->nChainWork); 
        assert(nHeight < 2 || (pindex->pskip && (pindex->pskip->nHeight < nHeight))); 
        assert(pindexFirstNotTreeValid == nullptr); 
        if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE) assert(pindexFirstNotTreeValid == nullptr); 
        if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_CHAIN) assert(pindexFirstNotChainValid == nullptr); 
        if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_SCRIPTS) assert(pindexFirstNotScriptsValid == nullptr); 
        if (pindexFirstInvalid == nullptr) {
            
            assert((pindex->nStatus & BLOCK_FAILED_MASK) == 0); 
        }
        if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) && pindexFirstNeverProcessed == nullptr) {
            if (pindexFirstInvalid == nullptr) {
                
                
                
                
                if (pindexFirstMissing == nullptr || pindex == m_chain.Tip()) {
                    assert(setBlockIndexCandidates.count(pindex));