When --fix-case was used (e.g. by bisync) on backends that can't set
modification times in place - such as Dropbox - files whose content
matched but whose modtimes differed would fail to rename with a
"from_lookup/not_found" error and abort the operation.
This happened because operations.NeedTransfer was called before the
fix-case rename. NeedTransfer's equality check would delete the
destination as a precursor to re-uploading it (the standard way to
update a modtime on these backends), so by the time the rename ran the
file no longer existed on the remote.
Fix by running the fix-case rename first, so that any subsequent
delete/re-upload happens at the correctly-cased destination path.
See: #8881
Nick Craig-Wood
de67f29b3f