For it to be useful for `trail`, the `prebuild` hook has to run
after both pagespecs and sorting work. The other use case
-I've seen for a similar hook was for Guiseppe Bilotta to
+I've seen for a similar hook was for Giuseppe Bilotta to
sort an inline-of-inlines by mtime of newest post, but that
can't be the same hook, because it has to run after pagespecs
work, but before sorting.
>> utime or sleep; I chose utime, since sleeping for 1 second would
>> slow down the test significantly. Please merge or cherry-pick
>> `smcv/trail-test` (there's only one commit). --[[smcv]]
+
+----
+
+[[!template id=gitbranch branch=smcv/ready/trail author=smcv]]
+
+Some later changes to trail:
+
+* Display the trail links at beginning/end of default `page.tmpl`
+ as suggested on IRC
+* Improve CSS, particularly in blueview and goldtype themes
+ ([example](http://blueview.hosted.pseudorandom.co.uk/posts/second_post/))
+* Fix a possible bug regarding state deletion
+
+--[[smcv]]
+
+> Applied --[[Joey]]
+
+----
+
+### Trail plugin creates unexpected interdependencies?
+*(ikiwiki master branch 2014-06-06 also tested with 3.20140228 release)*
+
+I noticed the problem when using the [[/plugins/contrib/album]] plugin but a bit of testing revealed that the [[trail]] plugin, which is used by [[/plugins/contrib/album]] may be the cause of the problem.
+
+On a site with the following structure where all albumN.mdwn files have the `\[[!inline pages="page(./album01/*)" trail="yes"]]` directive set. All albumN pages and imgN pages get rebuilt whenever any one of the albumN or imgN pages are changed and the command `ikiwiki --setup wiki.setup --refresh --verbose`
+ is issued.
+
+ /index.mdwn Contains no links maps or inlines
+ |-album01.mdwn \[[!inline pages="page(./album01/*)" trail="yes"]]
+ |-album01/
+ | |-imgA.mdwn
+ | |-imgB.mdwn
+ |
+ |-album02.mdwn \[[!inline pages="page(./album02/*)" trail="yes"]]
+ |-album02/
+ | |-imgC.mdwn
+ | |-imgD.mdwn
+ |
+ |-album03.mdwn \[[!inline pages="page(./album03/*)" trail="yes"]]
+ |-album03/
+ | |-imgE.mdwn
+ | |-imgF.mdwn
+
+Changing the index.mdwn page also triggers a full rebuild of all pages with [[trail]] directives. My sites tend to look like the above but with double digit numbers of files in at each level. Changing any file then means a full rebuild of a rather complex site which takes a long time.
+
+My setup and test may very well have mistakes but perhaps someone using the trail plugin could check (using the --verbose flag) if all their trails get rebuild when changing only one. I also find it curious that changes to the parent index.mdwn page triggers the same behaviour.
+
+I have removed a similar comment from the album discussion.
+
+ --[[kjs]]
+
+> I would expect changing imgE.mdwn to rebuild album03.mdwn (because album03
+> inlines imgE) and vice versa (because imgE uses album03's \[[!meta title]]).
+>
+> I would not expect changing imgE.mdwn or album03.mdwn to affect album02
+> or imgC.
+>
+> I would also not expect changing index.mdwn to rebuild anything else
+> unless there is a valid dependency reason to do so.
+>
+> Can you reproduce this problem in a wiki that does not contain anything
+> private, and publish its git repo somewhere? (I realise photo galleries
+> tend to be more personal/private than typical wikis, so you don't
+> necessarily want to link the real thing - that's why my album demos
+> tend to use dummy data). --[[smcv]]
+
+>> I was expecting the same depends pattern you describe.
+>> My photo wikis are mostly public so I've set up a publicly accessible repo
+>> (update-server-info type, git clone the first link below), a low-res copy of
+>> the underlay and a quick sanitized setup file.
+
+>>* [[http://www.kalleswork.net/downloads/stockholm/.git]]
+>>* [[http://www.kalleswork.net/downloads/stockholm.underlay.tar.gz]]
+>>* [[http://www.kalleswork.net/downloads/stockholm.setup]]
+
+>> It might be a bit unwieldly and the site itself at [[http://stockholm.kalleswork.net]]
+>> uses a few tweaks to the album templates and css, but I don't currently
+>> have access to the machine where I setup a cleaner debug wiki to test.
+>> (travelling atm). The images will likely be distorted due to the up scaling
+>> bug in the [[img]] plugin but other than that it should work.
+
+>> Let me know if you need anything else. Would be great to hear it works
+>> as expected for everyone else ;) --[[kjs]]
+
+>>> Hmm. Investigating the indexdb:
+>>>
+>>> perl -le 'use Storable; my $index = Storable::retrieve("stockholm/.ikiwiki/indexdb"); use Data::Dumper; print Dumper $index' |less
+>>>
+>>> indicates that `20130504` depends on `internal(*)` and so does `20130505`.
+>>>
+>>> After adding some `Carp::cluck` calls to the bits of IkiWiki.pm that add
+>>> dependencies, this turns out to be two similar issues, in `album` and
+>>> `trail`: they each use `pagespec_match_list` with the pagespec
+>>> `internal(*)` in order to apply a trivial filter (accept everything)
+>>> to an existing list for its side-effect of sorting that list.
+>>> Bug filed as [[bugs/trails depend on everything]] --smcv