Serializing Nested Array of Tables incorrectly

[alanhdu]

The TOML table equivalent to the following JSON:

{"table": [
  {"inner": [ {} ] }
]}

should serialize into

[[table]]
  [[table.inner]]

Instead, it serializes into:

[[table.inner]]

which is equivalent to {'table': {'inner': [{}]}}.

Found with rust-fuzz/targets#72.

[alanhdu]

One result of this is that

extern crate toml;

fn main() {
    let s = r#"
    [[table]]
      [[table.inner]]
    "#;
    let data: toml::Value = toml::from_str(s).unwrap();

    println!("{}", toml::to_string(&data).unwrap());
}

outputs

[[table.inner]]