user_mail_tokens() doc is missing doc of required fields

The documentation for the user_mail_tokens() function reads:

/**
 * Return an array of token to value mappings for user e-mail messages.
 *
 * @param $account
 *  The user object of the account being notified.  Must contain at
 *  least the fields 'uid', 'name', and 'mail'.
 * @param $language
 *  Language object to generate the tokens with.
 * @return
 *  Array of mappings from token names to values (for use with strtr()).
 */

However, user_mail_tokens unconditionally calls user_pass_reset_url() which assumes the existence of 'pass' and 'login' fields, in order to set the '!login_url' token.

I can think of at least three possible fixes for this inconsistency:

1. Revise the documentation to note the additional requirements of the 'pass' and 'login' fields.
2. Set the '!login_url' token to url('user/login') if the 'pass' and 'login' fields are not supplied.
3. Call user_load() if the 'pass' and 'login' fields are not supplied.

Three trivial patches attached; pick one.