field_reassign_with_default could be false positive

[Fullstop000]

I tried this code:

#[derive(Clone, Default)]
pub struct FileNode {
    name: String,
    delay_data_sync: Arc<AtomicBool>,
}

impl Drop for FileNode {
    fn drop(&mut self) {
        self.close()
    }
}

impl FileNode {
    fn new(name: &str) -> Self {
        let mut f = FileNode::default();
        f.name = name.to_owned();
        f
    }
    
    fn close(&self) {}
}

I expected to see this happen:
Clippy reports ok as FileNode implements Drop manually

Instead, this happened:
Clippy complains about field assignment outside of initializer for an instance created with Default::default(). If refactoring the codes as the suggestion clippy provides, rustc just throws the error:

cannot move out of type `FileNode`, which implements the `Drop` trait
move occurs because value has type `Arc<AtomicBool>`, which does not implement the `Copy` trait rustc(E0509)

Meta

• cargo clippy -V: clippy 0.0.212 (1773f60 2020-11-08)
• rustc -Vv:

rustc 1.49.0-nightly (1773f60ea 2020-11-08)
binary: rustc
commit-hash: 1773f60ea5d42e86b8fdf78d2fc5221ead222bc1
commit-date: 2020-11-08
host: x86_64-unknown-linux-gnu
release: 1.49.0-nightly

[flip1995]

Can you provide an example on playground? I don't get this error after applying the lint: Playground

[Fullstop000]

@flip1995 Sorry I forgot to post the Drop part
https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=3f6e5e3e6ca7da0317fb753cf0d2a1bd

[ebroto]

Indeed, the Drop part is important. We hit E0509 because functional record update moves or copies the remaining fields. Since Arc<AtomicBool> does not implement Copy we are moving out of the struct that implements Drop.

To fix this, we should avoid linting if the type implements Drop and has any field which is not Copy.