Passing None for args results in empty string passed to module

[jsturtevant]

When passing None to a loaded module, it causes the module to end up with one argument passed with a "":

let wasi_module = vm
            .wasi_module_mut()
            .ok_or_else(|| anyhow::Error::msg("Not found wasi module"))
            .map_err(|err| ExecutorError::Execution(err.into()))?;

wasi_module.initialize(
            None,
            Some(envs.iter().map(|s| s as &str).collect()),
            None,
        );

results in module that gets an arg:

fn main() {
    let args: Vec<_> = env::args().collect();
    let mut cmd = "daemon";
    if !args.is_empty() {
      //!! args isn't empy! it is ""
    }

See containerd/runwasi#146 (comment) for more info.

It looks like the code here is pushing something onto the args for the module:

wasmedge-rust-sdk/crates/wasmedge-sys/src/instance/module.rs

Lines 551 to 564 in 441dfe1

	pub fn init_wasi(
	&mut self,
	args: Option<Vec<&str>>,
	envs: Option<Vec<&str>>,
	preopens: Option<Vec<&str>>,
	) {
	// parse args
	let cstr_args: Vec<_> = match args {
	Some(args) => args
	.iter()
	.map(|&x| std::ffi::CString::new(x).unwrap())
	.collect(),
	None => vec![],
	};

[jsturtevant]

So I ended up figuring out this isn't really a bug since the first parameter to wasm modules should be the program name to match things like c/c++.