The git checkout and build process can leave the checkout
date in the tarball release, leading to unstable sorting.
I tried to use `git restore-mtime`, but that doesn't work for
ikiwiki, because dgit interferes with it.
When building ikiwiki from a tarball, the mtime (conceptually, the
last modification date of the file) is preserved by tar, but the inode
change time (creation/metadata-change date of *this copy* of the file)
is not. This seems to lead to unstable sort ordering and
unreproducible builds.
The page can't possibly have been modified before it was created, so
we can assume that the modification date is an upper bound for the
creation date.
This avoids nasty surprises on upgrade if a site is using httpauth,
or passwordauth with an account_creation_password, and relying on
only a select group of users being able to edit the site. We can revisit
this for ikiwiki 4.
srcfile_stat got called on a file from the underlay that no longer existed.
I am not 100% sure of the circumstances of that; I was able to reproduce
the bug but neglected to snapshot the tree, and then accidentially
got it to stop crashing. I know that a transient tag page got deleted using
the web interface to trigger the crash.
It seems that process_changed_files must have returned the file, despite it
being deleted. And since the file was not checked into git, it seems it
must have not been included in @IkiWiki::underlayfiles, which would have
caused process_changed_files to not return it.
I do not know why a transient tag page would not be in
@IkiWiki::underlayfiles. There is a bug here that I don't understand.
This is just a workaround -- run srcfile_stat such that it won't crash,
and if it is unable to stat a file, find_changed knows it's not changed,
so it's ok to skip it.
Also made find_new_files run srcfile_stat such that it won't crash, just
because I was there.
- suggest ghostscript (required for PDF-to-PNG thumbnailing)
and libmagickcore-extra (required for SVG-to-PNG thumbnailing)
- build-depend on ghostscript so the test for scalable images can be run