make sure only users with valid mail addresses can subscribe

in principle, this seems good. however, a few issues with this:

• shouldn't we gracefully handle anonymous users here with a "Please [login] or [register] to subscribe to issues" sort of thing?
• if we're changing this code, i'd rather see global $user instead of screwing with $GLOBALS['user'] directly like this.

attached gets rid of the ugly globals var, and adds support for anon users.

question: might it be a better idea to simply access control the menu callback so anon can't get to it?

A) url() calls should always be escaped with '@' inside t(), not '!'.

B) We should add a drupal_get_destination() on the url() for anonymous, so that when the login, they get redirected back here.

attached should address your concerns.

Cool, thanks. Sorry I didn't notice/mention these before, but:

C) Couldn't we include a destination on the url for the profile edit link, so that once they submit the changes on their user account form, they're sent back here?

D) the "register" part of "Please login or register" should be its own separate link (also with the destination). Therefore, you should probably call drupal_get_destination() once and stash that in a variable, which you share among both links, and, depending on if we can get (C) working, there, too...

Thanks!
-Derek

Fixed C and D from my previous comment. drupal_get_destination() works great for the link to fix your account. Also, I changed that so it sends you directly to the edit tab, instead of just user/[uid]. As far as I can tell, this is RTBC. Any final objections?

code looks good. fire at will

Committed to HEAD and installed on d.o. I'm not going to backport this.

I don't have a way to test this, but won't an empty address still be validated by valid_email_address()? According to http://api.drupal.org/api/function/valid_email_address/5 empty e-mail addresses are valid.

no, an empty string would fail because it doesn't contain @