gistfile1.diff

diff --git a/common/content/commands.js b/common/content/commands.js
--- a/common/content/commands.js
+++ b/common/content/commands.js
@@ -915,14 +915,22 @@
             }
 
             // highlight non-existent commands
-            let command = commands.get(cmd);
+            let command = Commands.prototype.get.call(subCmds ? {_exCommands: subCmds} : commands, cmd);
             if (!command) {
-                context.highlight(0, cmd.length, "SPELLCHECK");
+                if (!subCmds)
+                    context.highlight(0, cmd.length, "SPELLCHECK");
                 return;
             }
 
             // dynamically get completions as specified with the command's completer function
             [prefix] = context.filter.match(/^(?:\w*[\s!]|!)\s*/);
+            if (command.subCommands.length) {
+                context.fork("sub_" + command.name, prefix.length, this, "ex", command.subCommands);
+                let list = context.contextList;
+                if (/\/args$/.test(list[list.length -1].name))
+                    return;
+            }
+
             let cmdContext = context.fork(cmd, prefix.length);
             let argContext = context.fork("args", prefix.length);
             args = command.parseArgs(cmdContext.filter, argContext, { count: count, bang: bang });
@@ -949,9 +957,6 @@
                     }
                 }
             }
-
-            if (command.subCommands.length > 0)
-                context.fork("sub_" + cmd, prefix.length, this, "ex", command.subCommands);
         };
 
         completion.userCommand = function userCommand(context) {

gistfile2.js

//test
function num2chars(num) {
    var hintchars = "ZABCDEFGHIJKLMNOPQRSTUVWXY";
    var chars = "";
    var base = hintchars.length;
    do {
        chars = hintchars[num % base] + chars;
        num = Math.floor(num / base);
    } while (num > 0);
    return chars;
}

let res_str = [
["optest1", "sub sub test1"],
["optest2", "sub sub test2"],
["optest3", "sub sub test3"],
["optest4", "sub sub test4"],
["optest5", "sub sub test5"],
]

function showme (args) {
	liberator.echo("my name is " + this.name);
	for ([,a] in Iterator(Object.getOwnPropertyNames(args)))
		liberator.echo(a + " : " + args[a]);
}

commands.addUserCommand("cmdtop", "test", showme, {
	completer: completion.file,
	options: [
		[["-test", "-t"], commands.OPTION_LIST, null, [[num2chars(i), i] for (i in util.range(1, 10))], true],
	],
    literal: 0,
	subCommands: [
		let (i = num2chars(i))
		Command("scmd" + i, "sub command test" + i, showme, {
			options: [
				[["-noarg"]],
				[["-int"], commands.OPTION_INT]
			],
			completer: function (context) {
				context.title = [this.name + "'s completer", this.description];
				context.completions = [["comp" + this.name + ":" + j, this.name] for(j in util.range(1, 10))];
			},
			subCommands: [
				Command("sscmd" + i + num2chars(k), "sub sub commands " + k, showme, {
					options:[
						[["-tab" + k, "-t"], commands.OPTION_STRING, null, res_str ]
					],
					completer: function (context) {
						context.title = [this.name + "'s completer", this.description];
						context.completions = [[i, i * i * i] for (i in util.range(1, 10))];
					}
				}, true)
			for (k in util.range(1, 10))],
		}) for (i in util.range(1, 10))
	]
}, true);