Work around https://github.com/pcapriotti/optparse-applicative/issues/146
by not using action "file" and instead passing -o bashdefault -o default
to complete. This way, when optparse fails to complete a filename, bash
will fall back to regular filename completion.
Unfortunately, optparse-applicative does not provide a way to control the
options passed to complete, so I had to modify its generated completion script.
Note that for "git annex" command completion, git's completion script already
used -o bashdefault -o default, so that works too.
"checkPresent baser" was wrong; the baser has a dummy checkPresent action
not the real one. So, to fix this, we need to call preparecheckpresent to
get a checkpresent action that can be used to check if chunks are present.
Note that, for remotes like S3, this means that the preparer is run,
which opens a S3 handle, that will be used for each checkpresent of a
chunk. That's a good thing; if we're resuming an upload that's already many
chunks in, it'll reuse that same http connection for each chunk it checks.
Still, it's not a perfectly ideal thing, since this is a different http
connection that the one that will be used to upload chunks. It would be
nice to improve the API so that both use the same http connection.
This needs a patch to git to cause the git-annex completion to be
auto-loaded when completing "git annex <tab>". Otherwise, it will only
load when "git-annex" is tab completed. Once loaded, it works for both
uses. I've submitted the git patch to the git mailing list.