Before renaming a sync conflict, bisync checks whether the two files are
identical. It compares hashes using check or cryptcheck, and as a last
resort, when neither is available, it compares the files by downloading
them (--download), so that the result is certain regardless of checksum
support.
Before this change, the fallback to --download happened only when bisync
knew up front that the remotes had no usable hash. It did not happen
when a hash that was expected to be present turned out to be missing
(for example, a backend that normally supports hashes returned a blank
one, or cryptcheck could not get the underlying hash). Those files were
counted as identical based on size alone.
After this change, a missing hash falls back to --download, the same as
when the remotes have no hash in common. --size-only and
--ignore-checksum still disable the fallback and keep the size-only
comparison.
Co-Authored-By: ASRodrigo1 <45823308+asrodrigo1@users.noreply.github.com>
