`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 (it != pwallet->mapKeyMetadata.end()) {
            meta = &it->second;
        }
    }
    if (!meta) {
        auto it = pwallet->m_script_metadata.find(CScriptID(scriptPubKey));
        if (it != pwallet->m_script_metadata.end()) {
            meta = &it->second;
        }
    }
    if (meta) {
        ret.pushKV("timestamp", meta->nCreateTime);
        if (!meta->hdKeypath.empty()) {
            ret.pushKV("hdkeypath", meta->hdKeypath);
            ret.pushKV("hdseedid", meta->hd_seed_id.GetHex());
            ret.pushKV("hdmasterkeyid", meta->hd_seed_id.GetHex());
        }
    }
    
    
    
    UniValue labels(UniValue::VARR);
    std::map<CTxDestination, CAddressBookData>::iterator mi = pwallet->mapAddressBook.find(dest);
    if (mi != pwallet->mapAddressBook.end()) {
        labels.push_back(AddressBookDataToJSON(mi->second, true));
    }
    ret.pushKV("labels", std::move(labels));
    return ret;
}
static UniValue getaddressesbylabel(const JSONRPCRequest& request)