Function resolve_res_subdir

perro_source/devtools/perro_cli/src/scaffold.rs:124–154

(
    input: &str,
    res_root: &Path,
    allowed_prefix: &str,
)

}

fn resolve_res_subdir(
    input: &str,
    res_root: &Path,
    allowed_prefix: &str,
) -> Result<PathBuf, String> {
    let trimmed = input.trim();
    if trimmed.is_empty() {
        return Ok(res_root.to_path_buf());
    }

    let rel = if let Some(stripped) = trimmed.strip_prefix(allowed_prefix) {
        stripped.trim_start_matches('/').trim_start_matches('\\')
    } else if trimmed.contains("://") {
        return Err(format!(
            "path must use `{allowed_prefix}*` or `/...` style segments"
        ));
    } else if trimmed.starts_with('/') || trimmed.starts_with('\\') {
        trimmed.trim_start_matches('/').trim_start_matches('\\')
    } else {
        trimmed
    };

    let rel_path = PathBuf::from(rel);
    if rel_path
        .components()
        .any(|c| matches!(c, std::path::Component::ParentDir))
    {
        return Err("res subdir cannot contain `..` segments".to_string());
    }
    Ok(res_root.join(rel_path))
}

pub(crate) fn validate_dlc_name(raw: &str) -> Result<String, String> {
    let dlc = raw.trim();