Ignore annex.numcopies set to 0 in gitattributes or git config, or by
git-annex numcopies or by --numcopies, since that configuration would make
git-annex easily lose data. Same for mincopies.
This is a continuation of the work to make data only be able to be lost
when --force is used. It earlier led to the --trust option being disabled,
and similar reasoning applies here.
Most numcopies configs had docs that strongly discouraged setting it to 0
anyway. And I can't imagine a use case for setting to 0. Not that there
might not be one, but it's just so far from the intended use case of
git-annex, of managing and storing your data, that it does not seem like
it makes sense to cater to such a hypothetical use case, where any
git-annex drop can lose your data at any time.
Using a smart constructor makes sure every place avoids 0. Note that this
does mean that NumCopies is for the configured desired values, and not the
actual existing number of copies, which of course can be 0. The name
configuredNumCopies is used to make that clear.
Sponsored-by: Brock Spratlen on Patreon
This is conceptually very simple, just making a 1 that was hard coded be
exposed as a config option. The hard part was plumbing all that, and
dealing with complexities like reading it from git attributes at the
same time that numcopies is read.
Behavior change: When numcopies is set to 0, git-annex used to drop
content without requiring any copies. Now to get that (highly unsafe)
behavior, mincopies also needs to be set to 0. It seemed better to
remove that edge case, than complicate mincopies by ignoring it when
numcopies is 0.
This commit was sponsored by Denis Dzyubenko on Patreon.
