fix(gc): make --prune=now compatible with --expire-to

The original `git gc --prune=now` attempted to delete all unreachable
objects. However, after the introduction of `--cruft` and `--expire-to=<dir>`
in git gc, `--prune=now` can now compress unreachable objects into a
cruft pack and store them in the specified <dir> instead of deleting
them directly. This is beneficial for recovery in case of data corruption
during repository GC. Therefore, update the handling logic of `--prune=now`
in gc so that `-a` parameter is only passed to the repack command when
neither `--cruft` nor `--expire-to` are used.

Signed-off-by: ZheNing Hu <[email protected]>

builtin/gc.c

@@ -433,7 +433,8 @@ static int keep_one_pack(struct string_list_item *item, void *data UNUSED)
 static void add_repack_all_option(struct gc_config *cfg,
 				  struct string_list *keep_pack)
 {
-	if (cfg->prune_expire && !strcmp(cfg->prune_expire, "now"))
+	if (cfg->prune_expire && !strcmp(cfg->prune_expire, "now")
+		&& !(cfg->cruft_packs && cfg->repack_expire_to))
 		strvec_push(&repack, "-a");
 	else if (cfg->cruft_packs) {
 		strvec_push(&repack, "--cruft");