replace: prepare create_graft() for converting graft files wholesale

When converting all grafts in a graft file to replace refs, and one of
them happens to leave the original commit's parents unchanged, we do not
want to error out. Instead, we would like to issue a warning.

Prepare the create_graft() function for such a use case by adding a
`gentle` parameter. If set, we do not return an error when the replace ref
is unchanged, but a mere warning.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions