On my Linux Mint 19.1:
```bash
$ umask
0022
```

After the first run of `bitcoin-qt -sysperm=false` the `0700` permissions are expected for both the datadir (`~/.bitcoin`) and the walletdir (`~/.bitcoin/wallets`).

Actually, the directories are created with such access permissions:
```bash
$ stat ~/.bitcoin | grep Uid
Access: (0755/drwxr-xr-x)  Uid: ( 1000/ hebasto)   Gid: ( 1000/ hebasto)
$ stat ~/.bitcoin/wallets | grep Uid
Access: (0755/drwxr-xr-x)  Uid: ( 1000/ hebasto)   Gid: ( 1000/ hebasto)
```

Refs:
- #4286
- #13371
- #13389

NOTE: reading through the initial PR #4286 makes me think it was controversial. Is it a better and simpler way to just get rid of `-sysperm` option? I believe a user who needs this option can easily run `chown` command.
{
    
    
    if (args.IsArgSet("-bind")) {
        if (args.SoftSetBoolArg("-listen", true))
            LogPrintf("%s: parameter interaction: -bind set -> setting -listen=1\n", __func__);
    }
    if (args.IsArgSet("-whitebind")) {
        if (args.SoftSetBoolArg("-listen", true))
            LogPrintf("%s: parameter interaction: -whitebind set -> setting -listen=1\n", __func__);
    }
    if (args.IsArgSet("-connect")) {
        
        if (args.SoftSetBoolArg("-dnsseed", false))
            LogPrintf("%s: parameter interaction: -connect set -> setting -dnsseed=0\n", __func__);
        if (args.SoftSetBoolArg("-listen", false))
            LogPrintf("%s: parameter interaction: -connect set -> setting -listen=0\n", __func__);
    }
    std::string proxy_arg = args.GetArg("-proxy", "");