Unexpected Behaviour for #[serde(skip_serializing)]

[SZenglein]

I have the following struct:

#[derive(Deserialize, Serialize, ToSchema, Clone, PartialEq, Eq)]
pub struct Auth {
    pub user: String,
    #[serde(skip_serializing)]
    pub password: Option<String>,
}

The struct is used for authentication to an external service, so the password must be saved in plaintext. However I want to be sure I don't accidentally leak the password to a user request.

Note that the password field does not have a skip_deserializing field. It should still be possible to write the field.

I know there are other solutions for this particular problem, but I was surprised the field was completely missing in the generated code.

Suggested solution:
Fields that are either skipped on deserializing or serializing should be treated as optional fields, while only fields that are always skipped are omitted.