codex/codex-rs/config/src/merge.rs

use toml::Value as TomlValue;

/// Merge config `overlay` into `base`, giving `overlay` precedence.
pub fn merge_toml_values(base: &mut TomlValue, overlay: &TomlValue) {
    if let TomlValue::Table(overlay_table) = overlay
        && let TomlValue::Table(base_table) = base
    {
        for (key, value) in overlay_table {
            if let Some(existing) = base_table.get_mut(key) {
                merge_toml_values(existing, value);
            } else {
                base_table.insert(key.clone(), value.clone());
            }
        }
    } else {
        *base = overlay.clone();
    }
}