Improve git-annex's ability to find the path to its program, especially
when it needs to run itself in another repo to upgrade it.
Some parts of the code used readProgramFile, probably because I forgot that
programPath exists.
I noticed this when a git-annex auto-upgrade failed because it was running
git-annex upgrade --autoonly, but the code to run git-annex used
readProgramFile, which happened to point to an older build of git-annex.
This was originally added so that unannex could prevent the hook from
running while files were in a state that the hook would interpret as
old-style unlocked and so would lock.
Now that's gone, so the only thing the hook was preventing was two
pre-commit processes running simulantaneously. But such concurrency
is normal in git-annex and should not be a problem.
Does mean that .git/hooks/pre-commit-annex might run more concurrently,
that seems the only risk of it causing any problems.
When the recorded submodule commit changes on an adjusted branch, the
change is carried in the function that reverseAdjustedCommit passes
for adjustTree's adjusttreeitem parameter. Update the CommitObject
handling in adjustTree to consider adjusttreeitem so that a submodule
change is synced back.
Running `git annex add --force-small` on a modified submodule fails
when the submodule path is fed to hash-object. This failure is
unlikely to be triggered by a caller passing a submodule explicitly to
`git annex add` because there's nothing useful that annex-add can do
with a submodule. A more likely scenario for hitting this failure is
that the caller passes "." or a subdirectory to `annex-add` while a
submodule underneath the specified path happens to be modified.
addSmallOverridden already routes symbolic links through addFile
rather than using the custom hash-object/update-index call. The
latter is valid only for regular files, so extend this condition so
that everything that isn't a regular file goes through addFile. Doing
so avoids the above error because submodules come in as directories.
