Fix data loss bug in directory special remote

When moving a file to the remote failed, and partially transferred content
was left behind in the directory, re-running the same move would think it
succeeded and delete the local copy.

I reproduced data loss when moving files to a partition that was almost
full. Interrupting a transfer could have similar results.

Easily fixed by using a temp file which is then moved atomically into place
once the transfer completes.

I've audited other calls to copyFileExternal, and other special remote
file transfer code; everything else seems to use temp files correctly
(rsync, git), or otherwise use atomic transfers (bup, S3).

0 files changed, 0 insertions, 0 deletions