`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.
{
    LOCK(cs_wallets);
    return vpwallets;
}
std::shared_ptr<CWallet> GetWallet(const std::string& name)
{
    LOCK(cs_wallets);
    for (const std::shared_ptr<CWallet>& wallet : vpwallets) {
        if (wallet->GetName() == name) return wallet;
    }
    return nullptr;
}
static void ReleaseWallet(CWallet* wallet)
{
    wallet->WalletLogPrintf("Releasing wallet\n");
    wallet->BlockUntilSyncedToCurrentChain();
    wallet->Flush();
    delete wallet;
}
const uint32_t BIP32_HARDENED_KEY_LIMIT = 0x80000000;
const uint256 CMerkleTx::ABANDON_HASH(uint256S("0000000000000000000000000000000000000000000000000000000000000001"));
/** @defgroup mapWallet
 *
 * @{
 */
std::string COutput::ToString() const
{
    return strprintf("COutput(%s, %d, %d) [%s]", tx->GetHash().ToString(), i, nDepth, FormatMoney(tx->tx->vout[i].nValue));
}
class CAffectedKeysVisitor : public boost::static_visitor<void> {