The "pack_kept_objects" variable is defined as static to the repack
builtin, but is inherently related to the pack-objects arguments that
the builtin uses when generating new packs.
Move that field into the "struct pack_objects_args", and shuffle around
where we append the corresponding command-line option when preparing a
pack-objects process. Specifically:
- `write_cruft_pack()` always wants to pass "--honor-pack-keep", so
explicitly set the `pack_kept_objects` field to "0" when initializing
the `write_pack_opts` struct before calling `write_cruft_pack()`.
- `write_filtered_pack()` no longer needs to handle writing the
command-line option "--honor-pack-keep" when preparing a pack-objects
process, since its call to `prepare_pack_objects()` will have already
taken care of that.
`write_filtered_pack()` also reads the `pack_kept_objects` field to
determine whether to write the existing kept packs with a leading "^"
character, so update that to read through the `po_args` pointer
instead.
- `cmd_repack()` also no longer has to write the "--honor-pack-keep"
flag explicitly, since this is also handled via its call to
`prepare_pack_objects()`.
Since there is a default value for "pack_kept_objects" that relies on
whether or not we are writing a bitmap (and not writing a MIDX), extract
a default initializer for `struct pack_objects_args` that keeps this
conditional default behavior.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>