CLI::Option::envname() should trigger validators only if corresponding subcommand is called

[w3lld0ne]

Basic example:

auto CliApp = new CLI::App("myapp");
auto sub1 = CliApp->add_subcommand("sub1");
std::filesystem::path someFile = "";
sub1->add_option("-f,--file", someFile)->envname("SOME_FILE")->required()->expected(1)->check(CLI::ExistingFile);
auto sub2 = CliApp->add_subcommand("sub2");
int completelyUnrelatedToSub1 = 0;
sub2->add_option("-v,--value", completelyUnrelatedToSub1)->required()->expected(1);

try
{
	CliApp->parse(argsCount, args);
}
catch (const CLI::ParseError& e)
{
	return CliApp->exit(e);
}

Here if I call myapp.exe sub2 -v 111 and I have %SOME_FILE% env var defined as invalid/non-existing file path (it's not happening if there is no such env var defined), CLI::ExistingFile validator will abort the execution, even though I haven't even called the subcommand it's defined for. If I'd want this check to happen in sub2, I'd simply add the same option to it as well.

Even better: try to call myapp.exe (no arguments) or myapp.exe -h and we'll be greeted with the same validation error. It's funny because the error states Run with --help for more information. and that's what we do :) The only thing that works fine is myapp.exe -v.

If I remove ->envname("SOME_FILE") part from --file option registration (or delete %SOME_FILE% var from environment), everything works as it should: it's still marked as ->required(), but this is checked only for execution of sub1 subcommand.

P.S. I'm on Windows 11 22H2, compiling release v2.3.2 in VS2022 17.6.4 in C++20 mode. Will try the main branch soon.

[phlptp]

I will check on this, thanks.