p2p --pair: Fix interception of the magic-wormhole pairing code, which
since 0.8.2 it has sent to stderr rather than stdout.
This is highly annoying because I had asked the magic wormhole developers
for a machine-readable way to get the data, and instead they changed how
the data was output, and didn't even mention this in my issue, or in the
changelog.
Seems this needs to be tested periodically to make sure it's still working.
This commit was sponsored by Ethan Aubin.
Wormhole pairing will start to provide an appid to wormhole on 2021-12-31.
An appid can't be provided now because Debian stable is going to ship a
older version of git-annex that does not provide an appid. Assumption is
that by 2021-12-31, this version of git-annex will be shipped in a Debian
stable release. If that turns out to not be the case, this change will need
to be cherry-picked into the git-annex in Debian stable, or its wormhole
pairing will break.
This commit was sponsored by Thomas Hochstein on Patreon.
This interacts with it using stdio, which is surprisingly hard.
sendFile does not currently work, due to
https://github.com/warner/magic-wormhole/issues/108
Parsing the output to find the magic code is done as robustly as
possible, and should continue to work unless wormhole radically changes
the format of its codes. Presumably it will never output something that
looks like a wormhole code before the actual wormhole code; that would
also break this. It would be better if there was a way to make
wormhole not mix the code with other output, as requested in
https://github.com/warner/magic-wormhole/issues/104
Only exchange of files/directories is supported. To exchange messages,
https://github.com/warner/magic-wormhole/issues/99 would need to be resolved.
I don't need message exchange however.
