Bug in optflagopt

[pecastro]

I've bumped into some weird behaviour in another project whereas the use of an optflagopt option seemed to render unexpected behaviour of the option not being properly parsed.

I decided to come to the source and I extended the mod.rs test to show that something was amiss
pecastro@de5e4db

I've managed to make the test panic when you use an optflagopt in combination with other options.
Initial investigations from debugging the test show that the vals Vec of the Matches struct will have a Vec with Given rather than the option value specified and that is what's causing the return of None and triggering the panic.

self.vals:

[[(0, Val("foo"))], [(1, Val("bar"))], [], [(2, Given)]]

[ghostd]

Hi,

It seems to be expected:

getopts/src/tests/mod.rs

Lines 412 to 427 in c11eb65

	let long_args = vec!["--test=x".to_string()];
	match opts.parse(&long_args) {
	Ok(ref m) => {
	assert_eq!(m.opt_str("t").unwrap(), "x");
	assert_eq!(m.opt_str("test").unwrap(), "x");
	}
	_ => panic!(),
	}
	let long_args = vec!["--test".to_string(), "x".to_string()];
	match opts.parse(&long_args) {
	Ok(ref m) => {
	assert_eq!(m.opt_str("t"), None);
	assert_eq!(m.opt_str("test"), None);
	}
	_ => panic!(),
	}

[pecastro]

After digging a bit deeper the issue seems to be mainly to do with the parsing of an optflagopt whereby an -o=foo, -o foo, and --option=foo are parsed correctly whereas the --option foo is leaving foo as free an not consuming it as the argument to the option.

[pecastro]

@ghostd Yes, I've seen that whilst I was writing a fix and I'm correcting that test which I think it is wrong in my opinion.
The documentation for the method https://docs.rs/getopts/0.2.21/getopts/struct.Options.html#method.optflagopt doesn't specify that when the long option is used any optional parameter should be ignored ...

[pecastro]

Upon further attentive reading I did spot under the Parsing section of the Linux getopt user command https://man7.org/linux/man-pages/man1/getopt.1.html on the second to last paragraph the rules of engagement regarding the handling of optional arguments.
What tripped me was the absence in this documentation of any similar indication regarding the behaviour.
The https://man7.org/linux/man-pages/man3/getopt.3.html library does not state any such behaviour.

I've close the associated MR for now and I'll close this afterwards if no other insightful comments materialize ...