A backup reads from the source and writes it to the backup target
(repository). The name "target" is kept within the source code as it's
used there excessively.
This also includes two derived options `--from-insecure-no-password`
used for commands that require specifying a source repository. And
`--new-insecure-no-password` for the `key add` and `key passwd`
commands.
Specifying `--insecure-no-password` disabled the password prompt and
immediately uses an empty password. Passing a password via CLI option or
environment variable at the same time is an error.
use the same index size for compressed and uncompressed indexes.
Otherwise, decoding the index of a compressed repository requires
significantly more memory.
To prevent accidentally wiping all snapshots from a repository, that
option can only be used if either a snapshot filter or a keep policy is
specified.
Essentially, the option allows `forget --tag something
--unsafe-allow-remove-all` calls to remove all snapshots with a specific
tag.
`--keep-tag invalid-tag` was previously able to wipe all snapshots in a
repository. As a user specified a `--keep-*` option this is likely
unintentional. This forbid deleting all snapshot if a `--keep-*` option
was specified to prevent data loss. (Not specifying such an option
currently also causes the command to abort)
Depending on how long an operation takes to fail, the total retry
duration can currently vary between 1.5 and 15 minutes. In particular
for temporarily interrupted network connections, the former timeout is
too short. Thus always use a limit of 15 minutes.
The StdioWrapper type is really just a pair of io.WriteClosers, so
remove it in favor of a function that returns two of those. Test
coverage increases because the removed code was not tested.
RemoveUnpacked will eventually block removal of all filetypes other than
snapshots. However, getting there requires a major refactor to provide
some components with privileged access.
LoadRaw also includes improved context cancellation handling similar to the
implementation in repository.LoadUnpacked.
The removed cache backend test will be added again later on.
We don't need `error` here: the only existing implementation
of `ErrorHandler` always call `Backup.Error` and all
implementations of `Backup.Error` always return nil.
