Fields that are string slices fail to validate when containing newlines

[LostLuma]

Using string slices in a validated struct instead of strings causes a validation error if the field sent by the client contains newlines.

Here is the struct I noticed this issue on:

#[derive(Deserialize, Serialize, Validate)]
pub struct CreateFile<'r> {
    #[validate(length(min = 1, max = 32))]
    name: Option<&'r str>,
    #[validate(length(min = 1, max = 300_000))]
    content: &'r str,
}

Sending a newline character in either field causes the server to respond with the following error:

{
    "code": 422,
    "message": "Unprocessable Entity. The request was well-formed but was unable to be followed due to semantic errors.",
    "errors": null
}

Replacing the content field type with String instead fixes the issue, which I did for the time being.
I'd however like to abstain from doing so since it is, as far as I'm aware, less efficient and Rocket discourages doing so.

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This issue is not present when using the validator crate on its own (neither version v0.16.1 nor v0.18.1 are affected).