`banlist.dat` was introduced in https://github.com/bitcoin/bitcoin/pull/6310, storing nodes that were automatically banned (due to exceeding the misbehavior threshold) and manually banned (through the `setban` RPC).

Automatic bans were removed in https://github.com/bitcoin/bitcoin/pull/19219 and replaced with a discouragement filter. That filter is not saved to disk/persisted over shutdown/startup. The `banlist.dat` therefore now only contains addresses that have been banned through the `setban` rpc.

Since https://github.com/bitcoin/bitcoin/pull/15935, we have a specific file for configuration that is updated through the RPC and persisted over shutdown/startup, namely `settings.json`. We should therefore move the manual ban configuration from `banlist.dat` to `settings.json`. Doing so has a couple of benefits:

- `settings.json` is human readable and easily analyzable by any json parser.
- we wouldn't need to maintain custom [de]serialization code for the `banlist.dat` file.

`banlist.dat` is expected to be fairly small and infrequently updated, so disk space/performance are not huge concerns.
{
    
    
    
    
    std::set_new_handler(std::terminate);
    LogPrintf("Error: Out of memory. Terminating.\n");
    
    std::terminate();
};
bool AppInitBasicSetup(const ArgsManager& args)
{
    
#ifdef _MSC_VER
    
    _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);
    _CrtSetReportFile(_CRT_WARN, CreateFileA("NUL", GENERIC_WRITE, 0, nullptr, OPEN_EXISTING, 0, 0));
    
    _set_abort_behavior(0, _WRITE_ABORT_MSG | _CALL_REPORTFAULT);
#endif
#ifdef WIN32
    
    HeapSetInformation(nullptr, HeapEnableTerminationOnCorruption, nullptr, 0);
#endif
    if (!InitShutdownState()) {
        return InitError(Untranslated("Initializing wait-for-shutdown state failed."));
    }
    if (!SetupNetworking()) {
        return InitError(Untranslated("Initializing networking failed."));