default value of global flags is not set on new nodes if creating user doesn't have access

Ugh, the break goes further than just that bit.

Even if I remove the passing of the $user param to flag_get_flags(), the flag is not set, because flag_field_attach_save(), which handles saving of flags for all edit forms, causes the usual flag access checks to happen:

    flag($state ? 'flag' : 'unflag', $flag_name, $id);

and hence because the current user can't use the flag, the access checks inside the flag handler return FALSE and nothing happens.

A bit of issue queue & git archaeology shows that:

1. this was originally fixed / implemented in #320276: Respect flag defaults on node/add forms regardless of permission, where hook_nodeapi() was changed to pass the $skip_permission_check parameter when flagging. However, this uses flag(), which at that commit DID NOT receive the extra parameter -- so AFAICT, the fix in fact didn't work.
2. it was then (further) broken by #1149496: Flagging on node form checks perms of node author - should check perms of active user, which removed the passing of the $skip_permission_check parameter (which was doing nothing anyway). This commit is only on 6x2x, however the (not very helpful) dump commit c36124e then puts all of 6x2x on 7x2x.

Tests + full patch.

Patches test results are as expected; committing.

Issue #1882006 by joachim: Fixed flag defaults not respected on node add form if creating user doesn't have access.

added detail