+the transient underlay. There is a regression test. However, this branch
+is blocked by working out what the desired behaviour is, on
+[[todo/autoindex_should_use_add__95__autofile]].
+
+> I wonder why this needs to be configurable? I suppose that gets back to
+> whether it makes sense to check these files in or not. The benefits of
+> checking them in:
+>
+> * You can edit them from the VCS, don't have to go into the web
+> interface. Of course, files from the underlays have a similar issue,
+> but does it make sense to make that wart larger?
+> * You can know you can build the same site with nothing missing
+> even if you don't there enable autoindex or whatever. (Edge case.)
+
+>> I'm not sure that that's a huge wart; you can always "edit by
+>> overwriting". If you're running a local clone of the wiki on your laptop
+>> or whatever, you have the underlays already, and can copy from there.
+>> Tag and autoindex pages have rather simple source code anyway. --s
+
+> The benefit of using transient pages seems to just be avoiding commit
+> clutter? For files that are never committed, transient pages are a clear
+> win, but I wonder if adding configuration clutter just to avoid some
+> commit clutter is really worth it.
+
+>> According to the last section of
+>> [[todo/auto-create_tag_pages_according_to_a_template]], [[chrysn]] and
+>> Eric both feel rather strongly that it should be possible to
+>> not commit any tags; in [[plugins/autoindex/discussion]],
+>> lollipopman and [[JoeRayhawk]] both requested the same for autoindex.
+>> I made it configurable because, as you point out,
+>> there are also reasons why it makes sense to check these
+>> automatically-created files in. I'm neutral on this, personally.
+>>
+>> If this is a point of contention, would you accept a branch that
+>> just adds `transient` and uses it for [[plugins/recentchanges]],
+>> which aren't checked in and never have been? I've split the
+>> branch up in the hope that *some* of it can get merged.
+>>
+>>> I will be happy to merge transient-recentchanges when it's ready.
+>>> I see no obstacle to merging transient-tag either, and am not
+>>> really against using it for autoindex or aggregate either
+>>> once they get completed.
+>>> I just wanted to think through why configurability is needed.
+>>> --[[Joey]]
+>>
+>> One potentially relevant point is that configuration clutter only
+>> affects the site admin whereas commit clutter is part of the whole
+>> wiki's history. --[[smcv]]
+
+> Anyway, the configurability
+> appears subtly broken; the default is only 1 if a new setup file is
+> generated. (Correction: It was not even the default then --[[Joey]])
+> With an existing setup file, the 'default' values in
+> `getsetup` don't take effect, so it will default to undef, which
+> is treated the same as 0. --[[Joey]]
+
+>> Fixed in the branches, hopefully. (How disruptive would it be to have
+>> defaults take effect whenever the setup file doesn't set a value, btw?
+>> It seems pretty astonishing to have them work as they do at the moment.) --s
+
+>>> Well, note that default is not actually a documented field in
+>>> getsetup hooks at all! (It is used in IkiWiki.pm's own `getsetup()`, and
+>>> the concept may have leaked out into one or two plugins (comments,
+>>> transient)).
+>>>
+>>> Running getsetup at plugin load time is something I have considered
+>>> doing. It would simplify some checkconfig hooks that just set hardcoded
+>>> defaults. Although since dying is part of the getsetup hook's API, it
+>>> could be problimaric.
+>>> --[[Joey]]