Whenever the edit form is submitted, but not saved, the page location
select should reduce to the currently selected value. This was only done
when previewing before, but is also needed in order to support the case of
adding an attachment to a page that is just being created.
Before this change, the attachment plugin would get a weird value in
$form->field("page"), that did not reflect the actual page location.
To handle this, avoid populating %renderedfiles in preview,
and in expiry, check if the file is in %renderedfiles, if it is
do not delete it since it was saved.
Conflicts:
IkiWiki/Plugin/recentchanges.pm
Note that smcv's approach of using urlto also gets the url right when
redirecting to a non-html file, which is a better approach than my recent
fix to recentchanges
Simon McVittie
Joey Hess