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.
Mutex m_unlock_mutex;
    bool Unlock(const SecureString& strWalletPassphrase, bool accept_no_keys = false);
    bool ChangeWalletPassphrase(const SecureString& strOldWalletPassphrase, const SecureString& strNewWalletPassphrase);
    bool EncryptWallet(const SecureString& strWalletPassphrase);
    void GetKeyBirthTimes(std::map<CKeyID, int64_t> &mapKeyBirth) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    unsigned int ComputeTimeSmart(const CWalletTx& wtx, bool rescanning_old_block) const;
    /**
     * Increment the next transaction order id
     * @return next transaction order id
     */
    int64_t IncOrderPosNext(WalletBatch *batch = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    DBErrors ReorderTransactions();
    void MarkDirty();
    
    
    
    
    
    
    using UpdateWalletTxFn = std::function<bool(CWalletTx& wtx, bool new_tx)>;
    CWalletTx* AddToWallet(CTransactionRef tx, const TxState& state, const UpdateWalletTxFn& update_wtx=nullptr, bool fFlushOnClose=true, bool rescanning_old_block = false);
    bool LoadToWallet(const uint256& hash, const UpdateWalletTxFn& fill_wtx) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    void transactionAddedToMempool(const CTransactionRef& tx, uint64_t mempool_sequence) override;
    void blockConnected(const CBlock& block, int height) override;
    void blockDisconnected(const CBlock& block, int height) override;
    void updatedBlockTip() override;
    int64_t RescanFromTime(int64_t startTime, const WalletRescanReserver& reserver, bool update);
    struct ScanResult {
        enum { SUCCESS, FAILURE, USER_ABORT } status = SUCCESS;