Re: [GSoC PATCH v4 7/7] Documentation/git-repack: document --drop-filtered and --dry-run

On Mon, Aug 10, 2026 at 7:41 PM Siddharth Shrimali
<[email protected]> wrote:

>  Documentation/git-repack.adoc | 37 +++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
>
> diff --git a/Documentation/git-repack.adoc b/Documentation/git-repack.adoc
> index 72c42015e2..63943b078c 100644
> --- a/Documentation/git-repack.adoc
> +++ b/Documentation/git-repack.adoc
> @@ -12,6 +12,7 @@ SYNOPSIS
>  'git repack' [-a] [-A] [-d] [-f] [-F] [-l] [-n] [-q] [-b] [-m]
>         [--window=<n>] [--depth=<n>] [--threads=<n>] [--keep-pack=<pack-name>]
>         [--write-midx[=<mode>]] [--name-hash-version=<n>] [--path-walk]
> +       [--filter=<filter-spec>] [--drop-filtered [--dry-run]]
>
>  DESCRIPTION
>  -----------
> @@ -182,6 +183,42 @@ depth is 4095.
>         `objects` and `objects/info/alternates` sections of
>         linkgit:gitrepository-layout[5].
>
> +--drop-filtered::
> +       Delete the local objects that match the `--filter` specification
> +       instead of keeping them in a separate packfile, reclaiming the
> +       disk space they occupy. This is intended for partial clones,
> +       where the filtered objects are promisor objects that remain
> +       recoverable from the promisor remote and are lazily re-fetched
> +       on demand when they are next needed.
> ++
> +Only large blobs are supported for now, so `--filter=blob:limit=<n>`
> +is currently the only accepted filter. Because dropped objects must be
> +recoverable, this option requires a promisor remote to be configured
> +and refuses to run otherwise.
> ++
> +This option requires `-a`, and implies `-d`: the objects are dropped by
> +rebuilding the promisor pack without them and then removing the now
> +redundant old packs, so the redundant packs must be deleted for the
> +space to actually be reclaimed. It is incompatible with `--filter-to`
> +and with bitmap writing (`-b`/`--write-bitmap-index`), since filtering
> +breaks the single-pack closure that bitmaps require. A bitmap setting
> +coming from configuration is silently disabled for the duration of the
> +command.
> ++
> +As a convenience since dropped objects remain recoverable by lazy fetch,
> +`--drop-filtered` refuses to run while another operation
> +(merge, rebase, am, cherry-pick, revert, or bisect) is in progress, to
> +avoid a surprising network fetch mid-operation, and refuses to drop any
> +blob that the current index references, since such a blob would only be
> +lazily re-fetched by the next command that inspects the working tree.
> +These checks are skipped in bare repositories, which have neither a
> +working tree nor an index.

I think this patch could be squashed into patch 5/7 ("builtin/repack:
actually drop filtered promisor blobs") except the above paragraph
which could be added by patch 6/7 ("builtin/repack: add guards for
--drop-filtered").

Thanks.