Steps to reproduce:

* Build with `integer` sanitizer
* `UBSAN_OPTIONS="suppressions=$(pwd)/test/sanitizer_suppressions/ubsan:print_stacktrace=1:halt_on_error=1:report_error_type=1" ./src/qt/bitcoin-qt`
* Enter into the RPC debug console: `decodepsbt "cHNidP8BAKOro2MDAwMDA5ggCAAA////CQAtAAD+///1AAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAJAAAAAAAAAAAAAAAAAAAAAAAAAD+///1Zm9ybmV3nWx1Y2vmelLmegAAAAAAAAAAAAAAAAAAAAMKAwMDAwMDAwMDAwMACvMBA3FkAAAAAAAAAAAABAAlAAAAAAAAACEWDQ0zDQ0NDQ0NDQ0NCwEAAH9/f39/fwMAAABNo6P///kAAA=="`
static constexpr uint8_t PSBT_IN_SCRIPTSIG = 0x07;
static constexpr uint8_t PSBT_IN_SCRIPTWITNESS = 0x08;
static constexpr uint8_t PSBT_IN_RIPEMD160 = 0x0A;
static constexpr uint8_t PSBT_IN_SHA256 = 0x0B;
static constexpr uint8_t PSBT_IN_HASH160 = 0x0C;
static constexpr uint8_t PSBT_IN_HASH256 = 0x0D;
static constexpr uint8_t PSBT_IN_TAP_KEY_SIG = 0x13;
static constexpr uint8_t PSBT_IN_TAP_SCRIPT_SIG = 0x14;
static constexpr uint8_t PSBT_IN_TAP_LEAF_SCRIPT = 0x15;
static constexpr uint8_t PSBT_IN_TAP_BIP32_DERIVATION = 0x16;
static constexpr uint8_t PSBT_IN_TAP_INTERNAL_KEY = 0x17;
static constexpr uint8_t PSBT_IN_TAP_MERKLE_ROOT = 0x18;
static constexpr uint8_t PSBT_IN_PROPRIETARY = 0xFC;
static constexpr uint8_t PSBT_OUT_REDEEMSCRIPT = 0x00;
static constexpr uint8_t PSBT_OUT_WITNESSSCRIPT = 0x01;
static constexpr uint8_t PSBT_OUT_BIP32_DERIVATION = 0x02;
static constexpr uint8_t PSBT_OUT_TAP_INTERNAL_KEY = 0x05;
static constexpr uint8_t PSBT_OUT_TAP_TREE = 0x06;
static constexpr uint8_t PSBT_OUT_TAP_BIP32_DERIVATION = 0x07;
static constexpr uint8_t PSBT_OUT_PROPRIETARY = 0xFC;
static constexpr uint8_t PSBT_SEPARATOR = 0x00;
const std::streamsize MAX_FILE_SIZE_PSBT = 100000000; 
static constexpr uint32_t PSBT_HIGHEST_VERSION = 0;
struct PSBTProprietary
{
    uint64_t subtype;
    std::vector<unsigned char> identifier;
    std::vector<unsigned char> key;
    std::vector<unsigned char> value;
    bool operator<(const PSBTProprietary &b) const {