We already have support in `git receive-pack` to deal with some legacy
repositories which have non-fatal issues.
Let's make `git fsck` itself useful with such repositories, too, by
allowing users to ignore known issues, or at least demote those issues
to mere warnings.
Example: `git -c fsck.missingEmail=ignore fsck` would hide
problems with missing emails in author, committer and tagger lines.
In the same spirit that `git receive-pack`'s usage of the fsck machinery
differs from `git fsck`'s – some of the non-fatal warnings in `git fsck`
are fatal with `git receive-pack` when receive.fsckObjects = true, for
example – we strictly separate the fsck.<msg-id> from the
receive.fsck.<msg-id> settings.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>