`ScanForWalletTransactions()` has the following comment about its return value:

```
 * Returns null if scan was successful. Otherwise, if a complete rescan was not
 * possible (due to pruning or corruption), returns pointer to the most recent
 * block that could not be scanned.
```

This is not strictly true. If `abortrescan` is called, then `ScanForWalletTransactions()` will return `nullptr`, even though the scan wasn't successful to the tip.

This in turn causes a minor bug in `importmulti`, where the call doesn't return the correct error and warning about potentially not finding transactions if `abortrescan` was called.

I think the correct fix is for `ScanForWalletTransactions()` to inform the caller that the rescan was aborted.
{
    if (!MoneyRange(txout.nValue))
        throw std::runtime_error(std::string(__func__) + ": value out of range");
    return ((IsMine(txout) & filter) ? txout.nValue : 0);
}
bool CWallet::IsChange(const CTxOut& txout) const
{
    return IsChange(txout.scriptPubKey);
}
bool CWallet::IsChange(const CScript& script) const
{
    
    
    
    
    
    
    
    if (::IsMine(*this, script))
    {
        CTxDestination address;
        if (!ExtractDestination(script, address))
            return true;
        LOCK(cs_wallet);
        if (!mapAddressBook.count(address))
            return true;
    }
    return false;
}
CAmount CWallet::GetChange(const CTxOut& txout) const