builtin/repack: add guards for --drop-filtered

--drop-filtered removes local promisor blobs. That is only safe when the
repository is not mid-operation and when the blobs are not actively in
use, so add two guards, both skipped for bare repositories which have
neither a worktree nor an index.

First, refuse to run while a merge, rebase, am, cherry-pick, revert, or
bisect is in progress. During these operations the working tree and
index are in an intermediate state, and rewriting packs and deleting
objects underneath a half-finished operation is unsafe.

Second, refuse to drop a blob that the current index references. Such a
blob is needed by the working tree, so dropping it would only cause the
next command that touches the worktree to lazy-fetch it straight back,
reclaiming nothing. The offending path is reported so the user can see
why the drop was refused.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Siddharth Asthana <siddharthasthana31@gmail.com>
Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions