> +static void env_append(struct argv_array *env, const char *key, const
> +char *val) {
> + const char *old = getenv(key);
> +
> + if (!old)
> + argv_array_pushf(env, "%s=%s", key, val);
> + else
> + argv_array_pushf(env, "%s=%s%c%s", key, old, PATH_SEP,
> val);
>+}
I would like a comment explaining this function.
> + * Finalize a temporary object directory by migrating its objects into
> +the main
> + * object database.
> + */
This should mention that it frees its argument.