Why:
* When code throws a UserNotLoggedIn error for a temporary account,
this takes them to Special:UserLogin and asks them to log in to
an account
* Users using temporary accounts are less likely to have a named
account, so should instead be sent to Special:CreateAccount
(as described in T358586)
* When doing this, the warning message should be customised to
talk about the user needing to create an account (and not
log in)
What:
* Update UserNotLoggedIn to redirect to Special:CreateAccount
when the user is logged in to a temporary account
** The code which constructs the exception object can override
this and force the redirect to always be to Special:UserLogin.
* When the redirect is to Special:CreateAccount, allow customising
the message shown by adding a '-for-temp-user' suffix to the
message key in UserNotLoggedIn.
** This suffix is only added if the resulting message exists,
so that code can choose whether they need a message that is
different to the one on Special:UserLogin.
* Update SpecialPage::requiredNamedUser to allow special pages to
force the redirect to always be to Special:UserLogin
** This is made use of in Special:ChangeEmail and
Special:ConfirmEmail, as these special pages only make sense
for use with an existing account.
* Update and add message keys to allow a different message for
Special:CreateAccount.
* Update and add tests for these changes.
Bug: T358586
Change-Id: Ie0dd06f51b1e2b85eef6be377f673a02732ce604
0fa81768c2