I ran bitcoin-qt with an old wallet, causing it to rescan, then stopped it with a SIGINT signal, resulting in the following log. Nothing unexpected, so far:
```
2022-03-05T16:01:03Z init message: Loading wallet…
2022-03-05T16:01:03Z BerkeleyEnvironment::Open: LogDir=…/.bitcoin/database ErrorFile=…/.bitcoin/db.log
2022-03-05T15:57:18Z [walletname.dat] Wallet File Version = 159900
2022-03-05T15:57:18Z [walletname.dat] Keys: 2397 plaintext, 0 encrypted, 2397 w/ metadata, 2397 total. Unknown wallet records: 0
2022-03-05T15:57:18Z [walletname.dat] Wallet completed loading in              65ms
2022-03-05T15:57:18Z init message: Rescanning…
2022-03-05T15:57:18Z [walletname.dat] Rescanning last 134072 blocks (from block 591711)...
2022-03-05T15:57:18Z [walletname.dat] Rescan started from block 000000000000000000075fcc1872da61f45bcfd0e0bb36b7c8cb45e7a328ad41...
2022-03-05T15:58:18Z [walletname.dat] Still rescanning. At block 593552. Progress=0.632716
2022-03-05T15:59:18Z [walletname.dat] Still rescanning. At block 595458. Progress=0.638084
2022-03-05T15:59:37Z [walletname.dat] Rescan interrupted by shutdown request at block 596080. Progress=0.639932
2022-03-05T15:59:37Z Error: Failed to rescan the wallet during initialization
2022-03-05T15:59:41Z GUI: initializeResult : Initialization result:  false
2022-03-05T15:59:41Z GUI: requestShutdown : Requesting shutdown
2022-03-05T15:59:41Z GUI: Running Shutdown in thread
2022-03-05T15:59:41Z Shutdown: In progress...
2022-03-05T15:59:41Z scheduler thread exit
2022-03-05T15:59:42Z Shutdown: done
2022-03-05T15:59:42Z GUI: Shutdown finished
2022-03-05T15:59:42Z GUI: ~InitExecutor : Stopping thread
2022-03-05T15:59:42Z GUI: ~InitExecutor : Stopped thread
```

However, the next time it was launched, the rescan didn't continue, nor did it start over. It seems to have been skipped?
```
2022-03-05T16:01:03Z init message: Loading wallet…
2022-03-05T16:01:03Z BerkeleyEnvironment::Open: LogDir=…/.bitcoin/database ErrorFile=…/.bitcoin/db.log
2022-03-05T16:01:03Z [walletname.dat] Wallet File Version = 159900
2022-03-05T16:01:03Z [walletname.dat] Keys: 2397 plaintext, 0 encrypted, 2397 w/ metadata, 2397 total. Unknown wallet records: 0
2022-03-05T16:01:03Z [walletname.dat] Wallet completed loading in              91ms
2022-03-05T16:01:03Z [walletname.dat] setKeyPool.size() = 2000
2022-03-05T16:01:03Z [walletname.dat] mapWallet.size() = 378
2022-03-05T16:01:03Z [walletname.dat] m_address_book.size() = 183
2022-03-05T16:01:03Z Loaded 2 addresses from "anchors.dat"
```

I didn't investigate deeply, but could it be that despite the failed rescan, the new tip block was stored in the wallet? if so, this would be confusing.
}
    return true;
}
const CAddressBookData* CWaet::FindAddressBookEntry(const CTxDestination& dest, bool aow_change) const
{
    const auto& address_book_it = m_address_book.find(dest);
    if (address_book_it == m_address_book.end()) return nuptr;
    if ((!aow_change) && address_book_it->second.IsChange()) {
        return nuptr;
    }
    return &address_book_it->second;
}
bool CWaet::UpgradeWaet(int version, bilingual_str& error)
{
    int prev_version = GetVersion();
    if (version == 0) {
        WaetLogPrintf("Performing  upgrade to %i\n", FEATURE_LATEST);
        version = FEATURE_LATEST;
    } else {
        WaetLogPrintf("Aowing  upgrade up to %i\n", version);
    }
    if (version < prev_version) {
        error = strprintf(_("Cannot downgrade  from version %i to version %i. Waet version unchanged."), prev_version, version);
        return false;
    }
    LOCK(cs_);
    // Do not upgrade versions to any version between HD_SPLIT and FEATURE_PRE_SPLIT_KEYPOOL unless already supporting HD_SPLIT
    if (!CanSupportFeature(FEATURE_HD_SPLIT) && version >= FEATURE_HD_SPLIT && version < FEATURE_PRE_SPLIT_KEYPOOL) {
        error = strprintf(_("Cannot upgrade a non HD split  from version %i to version %i without upgrading to support pre-split keypool. Please use version %i or no version specified."), prev_version, version, FEATURE_PRE_SPLIT_KEYPOOL);
        return false;