Registering multi-dimensional (multiple subcommands) command arguments leads to a NPE

[sero583]

Expected Behavior

It to work.

Actual Behavior

Throws an NPE when trying to join (cant join server).

Steps to Reproduce

new CommandParameter[][] {
            new CommandParameter[] {
                new CommandParameter("opt1", false, new String[] { "opt1" }),
                new CommandParameter("player", CommandParamType.TARGET, false)
            },
            new CommandParameter[] {
                new CommandParameter("opt2", false, new String[] { "opt2" }),
                new CommandParameter("player", CommandParamType.TARGET, false)
            },
            new CommandParameter[] {
                new CommandParameter("opt2", false, new String[] { "opt2" }),
                new CommandParameter("player", CommandParamType.TARGET, false)
            }
        };

Use this as a command parameter for a command and set it on a command class, see that when you join it will throw this NPE.

Crashdump, Backtrace or Other Files

java.lang.NullPointerException: null
        at cn.nukkit.network.protocol.AvailableCommandsPacket.lambda$encode$1(AvailableCommandsPacket.java:79) ~[nukkit.jar:?]
        at java.util.HashMap.forEach(Unknown Source) ~[?:1.8.0_192]
        at cn.nukkit.network.protocol.AvailableCommandsPacket.encode(AvailableCommandsPacket.java:68) ~[nukkit.jar:?]
        at cn.nukkit.Server.batchPackets(Server.java:689) ~[nukkit.jar:?]
        at cn.nukkit.network.RakNetInterface.putPacket(RakNetInterface.java:176) ~[nukkit.jar:?]
        at cn.nukkit.Player.dataPacket(Player.java:1063) ~[nukkit.jar:?]
        at cn.nukkit.Player.sendCommandData(Player.java:595) ~[nukkit.jar:?]
        at cn.nukkit.Player.setEnableClientCommand(Player.java:574) ~[nukkit.jar:?]
        at cn.nukkit.Player.doFirstSpawn(Player.java:842) ~[nukkit.jar:?]
        at cn.nukkit.Player.sendNextChunk(Player.java:834) ~[nukkit.jar:?]
        at cn.nukkit.Player.checkNetwork(Player.java:1836) ~[nukkit.jar:?]
        at cn.nukkit.Server.tick(Server.java:1165) ~[nukkit.jar:?]
        at cn.nukkit.Server.tickProcessor(Server.java:931) [nukkit.jar:?]
        at cn.nukkit.Server.start(Server.java:899) [nukkit.jar:?]
        at cn.nukkit.Server.<init>(Server.java:580) [nukkit.jar:?]
        at cn.nukkit.Nukkit.main(Nukkit.java:120) [nukkit.jar:?]

[Sleepybear]

I believe you need to have a key for each parameter.

Try doing something like:

Map<String, CommandParameter[]> params = new HashMap<>();
params.put("opt1", 
    new CommandParameter[] {
                new CommandParameter("opt1", false, new String[] { "opt1" }),
                new CommandParameter("player", CommandParamType.TARGET, false)
            });
params.put("opt2", 
            new CommandParameter[] {
                new CommandParameter("opt2", false, new String[] { "opt2" }),
                new CommandParameter("player", CommandParamType.TARGET, false)
            });

It shouldn't matter what the key names are, as long as they are unique.

[sero583]

There is actually a key for it, but its numeric, anyway when putting the integer key inside (with a loop) it will throw this NPE