Type error pretty printer shows something strange

[ice1000]

Environment

• IntelliJ Rust plugin version: 0.2.104.2714-192-nightly

Problem description

I have a pattern match like this, and intellij-rust gives me a strange message:

It shouldn't be Option>. The declaration is like this:

And now I've found a minimum-reproducible example:

Code for copy-pasting:

enum A {
    B(Option<Box<A>>),
}

fn main() {
    let a = A::B(None);
    match a {
        A::B(_) => unimplemented!(),
    }
}

[ice1000]

Also, why am I having an error here? My pattern matchings are perfectly correct.

[ice1000]

Actually, once _ pattern is used, the pattern checker will complain.

[ice1000]

This is related to #3996

[ice1000]

I have taken a look at the PR. I guess the cause is that patFieldList does not return _ patterns

#3996 (comment)