Function lexical_clean_absolute_path

crates/openshell-cli/src/ssh.rs:829–852

Lexically clean a POSIX-style absolute path by resolving `.` and `..` components, collapsing repeated separators, and stripping any trailing slash. Returns `None` if the input is empty or relative — the caller is expected to reject those before reaching this helper. This is *lexical* only: it does not consult the filesystem and so cannot follow symlinks. That trade-off is intentional — the functi

(path: &str)

/// SSH command. Symlink-based escapes inside the sandbox must be addressed
/// server-side.
fn lexical_clean_absolute_path(path: &str) -> Option<String> {
    if !path.starts_with('/') {
        return None;
    }
    let mut stack: Vec<&str> = Vec::new();
    for component in path.split('/') {
        match component {
            "" | "." => {}
            ".." => {
                stack.pop();
            }
            other => stack.push(other),
        }
    }
    if stack.is_empty() {
        return Some("/".to_string());
    }
    let mut out = String::with_capacity(path.len());
    for component in stack {
        out.push('/');
        out.push_str(component);
    }
    Some(out)
}

/// Validate that a sandbox-side source path passed to `sandbox download`
/// resolves under the sandbox writable root.