`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.
int64_t nOrderPosOff = 0;
            for (const int64_t& nOffsetStart : nOrderPosOffsets)
            {
                if (nOrderPos >= nOffsetStart)
                    ++nOrderPosOff;
            }
            nOrderPos += nOrderPosOff;
            nOrderPosNext = std::max(nOrderPosNext, nOrderPos + 1);
            if (!nOrderPosOff)
                continue;
            
            if (!batch.WriteTx(*pwtx))
                return DBErrors::LOAD_FAIL;
        }
    }
    batch.WriteOrderPosNext(nOrderPosNext);
    return DBErrors::LOAD_OK;
}
int64_t CWallet::IncOrderPosNext(WalletBatch *batch)
{
    AssertLockHeld(cs_wallet); 
    int64_t nRet = nOrderPosNext++;
    if (batch) {
        batch->WriteOrderPosNext(nOrderPosNext);
    } else {
        WalletBatch(*database).WriteOrderPosNext(nOrderPosNext);
    }
    return nRet;
}
void CWallet::MarkDirty()