Duplicate negated options are accepted

[ifsheldon]

During the tests for the case-insensitive issue, it seems that I found one somewhat interesting issue(bug?).

    @Test
    public void testDuplicateNegatedOptionsRejected()
    {
        @CommandLine.Command(name = "negatable-options-demo")
        class NegatableOptionsDemo
        {
            @CommandLine.Option(names = "--verbose", negatable = true)
            boolean verbose= false;
            @CommandLine.Option(names = "--no-verbose")
            boolean nverbose = false;
        }
        NegatableOptionsDemo d = new NegatableOptionsDemo();
        CommandLine cmd = new CommandLine(d);
        cmd.execute("--verbose");
        assertTrue(d.verbose);
        assertFalse(d.nverbose);
        cmd.execute("--no-verbose");
        assertFalse(d.verbose); // it seems both fields have been set
        assertTrue(d.nverbose); // it seems both fields have been set
    }

I think this test should throw a duplication execption, but it passed.

[remkop]

Nice find, thank you!

Yes, this is a bug. It seems that when a negatable option is added, picocli checks that the option name and its negative form don't exist. However, when a non-negatable option is added, this check is not performed.