Added getStaged, to get the versions of git-annex branch files staged in its
index, and use during transitions so the result of merging sibling branches
is used.
The catFileStop in performTransitionsLocked is absolutely necessary,
without that the bug still occurred, because git cat-file was already
running and was looking at the old index file.
Note that getLocal still has cat-file look at the git-annex branch, not the
index. It might be faster if it looked at the index, but probably only
marginally so, and I've not benchmarked it to see if it's faster at all. I
didn't want to change unrelated behavior as part of this bug fix. And as
the need for catFileStop shows, using the index file has added
complications.
Anyway, it still seems fine for getLocal to look at the git-annex branch,
because normally the index file is updated just before the git-annex branch
is committed, and so they'll contain the same information. It's only during
a transition that the two diverge.
This commit was sponsored by Paul Walmsley in honor of Mark Phillips.
git-annex allows managing files with git, without checking the file
contents into git. While that may seem paradoxical, it is useful when
dealing with files larger than git can currently easily handle, whether due
to limitations in memory, checksumming time, or disk space.
For documentation, see doc/ or <https://git-annex.branchable.com/>