[meta] Anon flagging: things to check

$flag->theme():

- The variable $js_action isn't used.
- It seems we don't force the output to be the "Flag this!" link. See #996710: Anon flagging: Output of "flag this!" links only isn't enforced

$flag->_unflag():

- "$_COOKIE['flag']" is a typo.
- What's the purpose of these two lines? It should be documented (e.g., why it's not in _unflag_anonymous() instead).

See #1000128: Anon flagging: delete dead code

$this->_flag_anonymous() etc.:

I guess the lines "$_COOKIE['flags'] = $cookie_flags" and "$_COOKIE[$cookie_key] = 1" have some purpose. It should be documented.

This isn't important, now that our code isn't messy.

D7:

We use CACHE_DISABLED which doesn't seem to exist. (Maybe some of the other cache-related variables we use have changed in D7 as well.)

See #1001076: Anon flagging: CACHE_DISABLED gone in D7

Views:

        'value' => '***CURRENT_USER***',
        'numeric' => TRUE,
      );
      $join->extra[] = array(
        'field' => 'sid',
        'value' => flag_get_sid(),

We should use ***FLAG_SID*** instead of flag_get_sid() to make the query cacheable.

See #1003232: Use query substitution for the SID

D7: $flag->theme():

Why does the second drupal_add_js() call uses 'scope' but the first doesn't?

See #1005040: Fix parameters to drupal_add_js()

We have:

function flag_user($op, &$edit, &$account, $category = NULL) {
  switch ($op) {
    case 'login':
      // Migrate anonymous flags to this user's account.
      if (module_exists('session_api') && ($sid = flag_get_sid(0))) {

Should it be "flag_get_sid(0)" or "flag_get_sid()"?

(Yeah, it seems "flag_get_sid(0)" is correct (although I remember the author of Session API saying the SID is now preserved between logins). Whatever, it won't hurt to double check this part. MySQL does emit warning.)

We say, "Warning: Adding this relationship for any flag that contains anonymous flagging access will disable page caching for anonymous users when this view is executed. [...]"
But this is only true when [...]

See #1006526: Anon flagging: clarify Views warning