Sadly my bug report about this is not going to get fixed it seems, so
I have to drag around a whole added module file just to deal with it.
https://github.com/haskell/directory/issues/52
This is actually worse than I thought; when git is being run with a
detached work tree, GIT_INDEX_FILE is treated as a path relative to CWD,
instead of the normal behavior of relative the top of the work tree.
This seems to make it basically impossible for any program that wants to
use GIT_INDEX_FILE to use anything other than an absolute path to it; there
are too many configurations to keep straight that can change how git
interprets what should be a simple relative path to a file.
(I have complained to the git developers.)
This affected git annex view. It turns out that some other places
that use GIT_INDEX_FILE were already working around the bug. I removed the
workaround from Annex.Branch since the new workaround will do.
There's a potential race where the smudge filter is run at the same time an
object is being downloaded. If the download finished after the inAnnex
check, and before the keys db was updated, the associated file would not
get updated with the downloaded content.
I'm not sure this closes the race; it may only narrow the window. Problem
is, the keys database needs to communicate between two different processes.
In the case of the assistant, the transferkeys command is the other
process, and it closes the db handle after getting the file. So, it should
re-open the database and so see the update that the smudge filter has
written to it. But, what if the smudge filter takes a while to update the
database?
The keys database handle needs to be closed after merging, because the
smudge filter, in another process, updates the database. Old cached info
can be read for a while from the open database handle; closing it ensures
that the info written by the smudge filter is available.
This is pretty horribly ad-hoc, and it's especially nasty that the
transferrer closes the database every time.