Possible DB corruption bug

User's wallet failed to start due to this error:

```
DB verify checkpoint version: 0.25.0
[2019-06-03T00:24:15+02:00] INFO [main]: Checking database and resetting if corrupted
[2019-06-03T00:24:15+02:00] ERROR [visor]: bc.store.ForEachBlock failed: Not enough buffer data to deserialize
[2019-06-03T00:24:15+02:00] ERROR [main]: visor.ResetCorruptDB failed: Not enough buffer data to deserialize
[2019-06-03T00:24:15+02:00] INFO [main]: Closing database
[2019-06-03T00:24:15+02:00] INFO [main]: Goodbye
```

However, they did not send me the db file before he deleted it

The report contains only the database verification log and no database file, source location, or test case. Start by reproducing the reported Not enough buffer data to deserialize failure in the database-checking and reset path; done requires identifying a reproducible corruption case and confirming that recovery completes without the error.

Written by the indexing model from the issue text.