Usage is printed when all options have default values

[Matthiee]

Description

I have an option specified as

[Name("c", "check")]
[Description("Reports the amount of duplicates without changing anything")]
[DefaultValue(true)] // Note defaults to true and not required
public bool OnlyCheck { get; set; }

But still it prints the usages when it should not print them in this case.

Run without specifying the "check" option as CLI argument.

Workaround

Current workaround: setting AutoPrintUsageAndErrors = false.

Todo

Problem is caused by CommandLineParser`TOption.cs#L255-L265.

We wrongly assume noArgsSupplied means we should print the usage.
This is mostly correct but there is a scenario where this shouldn't.

A scenario where we only have optional options that have at least one with DefaultValue specified.