merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

1 files changed, 794 insertions, 0 deletions

diff --git a/third_party/git/shallow.c b/third_party/git/shallow.c
new file mode 100644
index 000000000000..5fa2b15d3705
--- /dev/null
+++ b/third_party/git/shallow.c
@@ -0,0 +1,794 @@
+#include "cache.h"
+#include "repository.h"
+#include "tempfile.h"
+#include "lockfile.h"
+#include "object-store.h"
+#include "commit.h"
+#include "tag.h"
+#include "pkt-line.h"
+#include "remote.h"
+#include "refs.h"
+#include "sha1-array.h"
+#include "diff.h"
+#include "revision.h"
+#include "commit-slab.h"
+#include "revision.h"
+#include "list-objects.h"
+#include "commit-slab.h"
+#include "repository.h"
+#include "commit-reach.h"
+
+void set_alternate_shallow_file(struct repository *r, const char *path, int override)
+{
+	if (r->parsed_objects->is_shallow != -1)
+		BUG("is_repository_shallow must not be called before set_alternate_shallow_file");
+	if (r->parsed_objects->alternate_shallow_file && !override)
+		return;
+	free(r->parsed_objects->alternate_shallow_file);
+	r->parsed_objects->alternate_shallow_file = xstrdup_or_null(path);
+}
+
+int register_shallow(struct repository *r, const struct object_id *oid)
+{
+	struct commit_graft *graft =
+		xmalloc(sizeof(struct commit_graft));
+	struct commit *commit = lookup_commit(the_repository, oid);
+
+	oidcpy(&graft->oid, oid);
+	graft->nr_parent = -1;
+	if (commit && commit->object.parsed)
+		commit->parents = NULL;
+	return register_commit_graft(r, graft, 0);
+}
+
+int is_repository_shallow(struct repository *r)
+{
+	/*
+	 * NEEDSWORK: This function updates
+	 * r->parsed_objects->{is_shallow,shallow_stat} as a side effect but
+	 * there is no corresponding function to clear them when the shallow
+	 * file is updated.
+	 */
+
+	FILE *fp;
+	char buf[1024];
+	const char *path = r->parsed_objects->alternate_shallow_file;
+
+	if (r->parsed_objects->is_shallow >= 0)
+		return r->parsed_objects->is_shallow;
+
+	if (!path)
+		path = git_path_shallow(r);
+	/*
+	 * fetch-pack sets '--shallow-file ""' as an indicator that no
+	 * shallow file should be used. We could just open it and it
+	 * will likely fail. But let's do an explicit check instead.
+	 */
+	if (!*path || (fp = fopen(path, "r")) == NULL) {
+		stat_validity_clear(r->parsed_objects->shallow_stat);
+		r->parsed_objects->is_shallow = 0;
+		return r->parsed_objects->is_shallow;
+	}
+	stat_validity_update(r->parsed_objects->shallow_stat, fileno(fp));
+	r->parsed_objects->is_shallow = 1;
+
+	while (fgets(buf, sizeof(buf), fp)) {
+		struct object_id oid;
+		if (get_oid_hex(buf, &oid))
+			die("bad shallow line: %s", buf);
+		register_shallow(r, &oid);
+	}
+	fclose(fp);
+	return r->parsed_objects->is_shallow;
+}
+
+/*
+ * TODO: use "int" elemtype instead of "int *" when/if commit-slab
+ * supports a "valid" flag.
+ */
+define_commit_slab(commit_depth, int *);
+struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
+		int shallow_flag, int not_shallow_flag)
+{
+	int i = 0, cur_depth = 0;
+	struct commit_list *result = NULL;
+	struct object_array stack = OBJECT_ARRAY_INIT;
+	struct commit *commit = NULL;
+	struct commit_graft *graft;
+	struct commit_depth depths;
+
+	init_commit_depth(&depths);
+	while (commit || i < heads->nr || stack.nr) {
+		struct commit_list *p;
+		if (!commit) {
+			if (i < heads->nr) {
+				int **depth_slot;
+				commit = (struct commit *)
+					deref_tag(the_repository,
+						  heads->objects[i++].item,
+						  NULL, 0);
+				if (!commit || commit->object.type != OBJ_COMMIT) {
+					commit = NULL;
+					continue;
+				}
+				depth_slot = commit_depth_at(&depths, commit);
+				if (!*depth_slot)
+					*depth_slot = xmalloc(sizeof(int));
+				**depth_slot = 0;
+				cur_depth = 0;
+			} else {
+				commit = (struct commit *)
+					object_array_pop(&stack);
+				cur_depth = **commit_depth_at(&depths, commit);
+			}
+		}
+		parse_commit_or_die(commit);
+		cur_depth++;
+		if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
+		    (is_repository_shallow(the_repository) && !commit->parents &&
+		     (graft = lookup_commit_graft(the_repository, &commit->object.oid)) != NULL &&
+		     graft->nr_parent < 0)) {
+			commit_list_insert(commit, &result);
+			commit->object.flags |= shallow_flag;
+			commit = NULL;
+			continue;
+		}
+		commit->object.flags |= not_shallow_flag;
+		for (p = commit->parents, commit = NULL; p; p = p->next) {
+			int **depth_slot = commit_depth_at(&depths, p->item);
+			if (!*depth_slot) {
+				*depth_slot = xmalloc(sizeof(int));
+				**depth_slot = cur_depth;
+			} else {
+				if (cur_depth >= **depth_slot)
+					continue;
+				**depth_slot = cur_depth;
+			}
+			if (p->next)
+				add_object_array(&p->item->object,
+						NULL, &stack);
+			else {
+				commit = p->item;
+				cur_depth = **commit_depth_at(&depths, commit);
+			}
+		}
+	}
+	for (i = 0; i < depths.slab_count; i++) {
+		int j;
+
+		for (j = 0; j < depths.slab_size; j++)
+			free(depths.slab[i][j]);
+	}
+	clear_commit_depth(&depths);
+
+	return result;
+}
+
+static void show_commit(struct commit *commit, void *data)
+{
+	commit_list_insert(commit, data);
+}
+
+/*
+ * Given rev-list arguments, run rev-list. All reachable commits
+ * except border ones are marked with not_shallow_flag. Border commits
+ * are marked with shallow_flag. The list of border/shallow commits
+ * are also returned.
+ */
+struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
+						    int shallow_flag,
+						    int not_shallow_flag)
+{
+	struct commit_list *result = NULL, *p;
+	struct commit_list *not_shallow_list = NULL;
+	struct rev_info revs;
+	int both_flags = shallow_flag | not_shallow_flag;
+
+	/*
+	 * SHALLOW (excluded) and NOT_SHALLOW (included) should not be
+	 * set at this point. But better be safe than sorry.
+	 */
+	clear_object_flags(both_flags);
+
+	is_repository_shallow(the_repository); /* make sure shallows are read */
+
+	repo_init_revisions(the_repository, &revs, NULL);
+	save_commit_buffer = 0;
+	setup_revisions(ac, av, &revs, NULL);
+
+	if (prepare_revision_walk(&revs))
+		die("revision walk setup failed");
+	traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
+
+	if (!not_shallow_list)
+		die("no commits selected for shallow requests");
+
+	/* Mark all reachable commits as NOT_SHALLOW */
+	for (p = not_shallow_list; p; p = p->next)
+		p->item->object.flags |= not_shallow_flag;
+
+	/*
+	 * mark border commits SHALLOW + NOT_SHALLOW.
+	 * We cannot clear NOT_SHALLOW right now. Imagine border
+	 * commit A is processed first, then commit B, whose parent is
+	 * A, later. If NOT_SHALLOW on A is cleared at step 1, B
+	 * itself is considered border at step 2, which is incorrect.
+	 */
+	for (p = not_shallow_list; p; p = p->next) {
+		struct commit *c = p->item;
+		struct commit_list *parent;
+
+		if (parse_commit(c))
+			die("unable to parse commit %s",
+			    oid_to_hex(&c->object.oid));
+
+		for (parent = c->parents; parent; parent = parent->next)
+			if (!(parent->item->object.flags & not_shallow_flag)) {
+				c->object.flags |= shallow_flag;
+				commit_list_insert(c, &result);
+				break;
+			}
+	}
+	free_commit_list(not_shallow_list);
+
+	/*
+	 * Now we can clean up NOT_SHALLOW on border commits. Having
+	 * both flags set can confuse the caller.
+	 */
+	for (p = result; p; p = p->next) {
+		struct object *o = &p->item->object;
+		if ((o->flags & both_flags) == both_flags)
+			o->flags &= ~not_shallow_flag;
+	}
+	return result;
+}
+
+static void check_shallow_file_for_update(struct repository *r)
+{
+	if (r->parsed_objects->is_shallow == -1)
+		BUG("shallow must be initialized by now");
+
+	if (!stat_validity_check(r->parsed_objects->shallow_stat,
+				 git_path_shallow(r)))
+		die("shallow file has changed since we read it");
+}
+
+#define SEEN_ONLY 1
+#define VERBOSE   2
+#define QUICK 4
+
+struct write_shallow_data {
+	struct strbuf *out;
+	int use_pack_protocol;
+	int count;
+	unsigned flags;
+};
+
+static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
+{
+	struct write_shallow_data *data = cb_data;
+	const char *hex = oid_to_hex(&graft->oid);
+	if (graft->nr_parent != -1)
+		return 0;
+	if (data->flags & QUICK) {
+		if (!has_object_file(&graft->oid))
+			return 0;
+	} else if (data->flags & SEEN_ONLY) {
+		struct commit *c = lookup_commit(the_repository, &graft->oid);
+		if (!c || !(c->object.flags & SEEN)) {
+			if (data->flags & VERBOSE)
+				printf("Removing %s from .git/shallow\n",
+				       oid_to_hex(&c->object.oid));
+			return 0;
+		}
+	}
+	data->count++;
+	if (data->use_pack_protocol)
+		packet_buf_write(data->out, "shallow %s", hex);
+	else {
+		strbuf_addstr(data->out, hex);
+		strbuf_addch(data->out, '\n');
+	}
+	return 0;
+}
+
+static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
+				   const struct oid_array *extra,
+				   unsigned flags)
+{
+	struct write_shallow_data data;
+	int i;
+	data.out = out;
+	data.use_pack_protocol = use_pack_protocol;
+	data.count = 0;
+	data.flags = flags;
+	for_each_commit_graft(write_one_shallow, &data);
+	if (!extra)
+		return data.count;
+	for (i = 0; i < extra->nr; i++) {
+		strbuf_addstr(out, oid_to_hex(extra->oid + i));
+		strbuf_addch(out, '\n');
+		data.count++;
+	}
+	return data.count;
+}
+
+int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
+			  const struct oid_array *extra)
+{
+	return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
+}
+
+const char *setup_temporary_shallow(const struct oid_array *extra)
+{
+	struct tempfile *temp;
+	struct strbuf sb = STRBUF_INIT;
+
+	if (write_shallow_commits(&sb, 0, extra)) {
+		temp = xmks_tempfile(git_path("shallow_XXXXXX"));
+
+		if (write_in_full(temp->fd, sb.buf, sb.len) < 0 ||
+		    close_tempfile_gently(temp) < 0)
+			die_errno("failed to write to %s",
+				  get_tempfile_path(temp));
+		strbuf_release(&sb);
+		return get_tempfile_path(temp);
+	}
+	/*
+	 * is_repository_shallow() sees empty string as "no shallow
+	 * file".
+	 */
+	return "";
+}
+
+void setup_alternate_shallow(struct lock_file *shallow_lock,
+			     const char **alternate_shallow_file,
+			     const struct oid_array *extra)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int fd;
+
+	fd = hold_lock_file_for_update(shallow_lock,
+				       git_path_shallow(the_repository),
+				       LOCK_DIE_ON_ERROR);
+	check_shallow_file_for_update(the_repository);
+	if (write_shallow_commits(&sb, 0, extra)) {
+		if (write_in_full(fd, sb.buf, sb.len) < 0)
+			die_errno("failed to write to %s",
+				  get_lock_file_path(shallow_lock));
+		*alternate_shallow_file = get_lock_file_path(shallow_lock);
+	} else
+		/*
+		 * is_repository_shallow() sees empty string as "no
+		 * shallow file".
+		 */
+		*alternate_shallow_file = "";
+	strbuf_release(&sb);
+}
+
+static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
+{
+	int fd = *(int *)cb;
+	if (graft->nr_parent == -1)
+		packet_write_fmt(fd, "shallow %s\n", oid_to_hex(&graft->oid));
+	return 0;
+}
+
+void advertise_shallow_grafts(int fd)
+{
+	if (!is_repository_shallow(the_repository))
+		return;
+	for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
+}
+
+/*
+ * mark_reachable_objects() should have been run prior to this and all
+ * reachable commits marked as "SEEN", except when quick_prune is non-zero,
+ * in which case lines are excised from the shallow file if they refer to
+ * commits that do not exist (any longer).
+ */
+void prune_shallow(unsigned options)
+{
+	struct lock_file shallow_lock = LOCK_INIT;
+	struct strbuf sb = STRBUF_INIT;
+	unsigned flags = SEEN_ONLY;
+	int fd;
+
+	if (options & PRUNE_QUICK)
+		flags |= QUICK;
+
+	if (options & PRUNE_SHOW_ONLY) {
+		flags |= VERBOSE;
+		write_shallow_commits_1(&sb, 0, NULL, flags);
+		strbuf_release(&sb);
+		return;
+	}
+	fd = hold_lock_file_for_update(&shallow_lock,
+				       git_path_shallow(the_repository),
+				       LOCK_DIE_ON_ERROR);
+	check_shallow_file_for_update(the_repository);
+	if (write_shallow_commits_1(&sb, 0, NULL, flags)) {
+		if (write_in_full(fd, sb.buf, sb.len) < 0)
+			die_errno("failed to write to %s",
+				  get_lock_file_path(&shallow_lock));
+		commit_lock_file(&shallow_lock);
+	} else {
+		unlink(git_path_shallow(the_repository));
+		rollback_lock_file(&shallow_lock);
+	}
+	strbuf_release(&sb);
+}
+
+struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
+
+/*
+ * Step 1, split sender shallow commits into "ours" and "theirs"
+ * Step 2, clean "ours" based on .git/shallow
+ */
+void prepare_shallow_info(struct shallow_info *info, struct oid_array *sa)
+{
+	int i;
+	trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
+	memset(info, 0, sizeof(*info));
+	info->shallow = sa;
+	if (!sa)
+		return;
+	ALLOC_ARRAY(info->ours, sa->nr);
+	ALLOC_ARRAY(info->theirs, sa->nr);
+	for (i = 0; i < sa->nr; i++) {
+		if (has_object_file(sa->oid + i)) {
+			struct commit_graft *graft;
+			graft = lookup_commit_graft(the_repository,
+						    &sa->oid[i]);
+			if (graft && graft->nr_parent < 0)
+				continue;
+			info->ours[info->nr_ours++] = i;
+		} else
+			info->theirs[info->nr_theirs++] = i;
+	}
+}
+
+void clear_shallow_info(struct shallow_info *info)
+{
+	free(info->ours);
+	free(info->theirs);
+}
+
+/* Step 4, remove non-existent ones in "theirs" after getting the pack */
+
+void remove_nonexistent_theirs_shallow(struct shallow_info *info)
+{
+	struct object_id *oid = info->shallow->oid;
+	int i, dst;
+	trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
+	for (i = dst = 0; i < info->nr_theirs; i++) {
+		if (i != dst)
+			info->theirs[dst] = info->theirs[i];
+		if (has_object_file(oid + info->theirs[i]))
+			dst++;
+	}
+	info->nr_theirs = dst;
+}
+
+define_commit_slab(ref_bitmap, uint32_t *);
+
+#define POOL_SIZE (512 * 1024)
+
+struct paint_info {
+	struct ref_bitmap ref_bitmap;
+	unsigned nr_bits;
+	char **pools;
+	char *free, *end;
+	unsigned pool_count;
+};
+
+static uint32_t *paint_alloc(struct paint_info *info)
+{
+	unsigned nr = DIV_ROUND_UP(info->nr_bits, 32);
+	unsigned size = nr * sizeof(uint32_t);
+	void *p;
+	if (!info->pool_count || size > info->end - info->free) {
+		if (size > POOL_SIZE)
+			BUG("pool size too small for %d in paint_alloc()",
+			    size);
+		info->pool_count++;
+		REALLOC_ARRAY(info->pools, info->pool_count);
+		info->free = xmalloc(POOL_SIZE);
+		info->pools[info->pool_count - 1] = info->free;
+		info->end = info->free + POOL_SIZE;
+	}
+	p = info->free;
+	info->free += size;
+	return p;
+}
+
+/*
+ * Given a commit SHA-1, walk down to parents until either SEEN,
+ * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
+ * all walked commits.
+ */
+static void paint_down(struct paint_info *info, const struct object_id *oid,
+		       unsigned int id)
+{
+	unsigned int i, nr;
+	struct commit_list *head = NULL;
+	int bitmap_nr = DIV_ROUND_UP(info->nr_bits, 32);
+	size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
+	struct commit *c = lookup_commit_reference_gently(the_repository, oid,
+							  1);
+	uint32_t *tmp; /* to be freed before return */
+	uint32_t *bitmap;
+
+	if (!c)
+		return;
+
+	tmp = xmalloc(bitmap_size);
+	bitmap = paint_alloc(info);
+	memset(bitmap, 0, bitmap_size);
+	bitmap[id / 32] |= (1U << (id % 32));
+	commit_list_insert(c, &head);
+	while (head) {
+		struct commit_list *p;
+		struct commit *c = pop_commit(&head);
+		uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
+
+		/* XXX check "UNINTERESTING" from pack bitmaps if available */
+		if (c->object.flags & (SEEN | UNINTERESTING))
+			continue;
+		else
+			c->object.flags |= SEEN;
+
+		if (*refs == NULL)
+			*refs = bitmap;
+		else {
+			memcpy(tmp, *refs, bitmap_size);
+			for (i = 0; i < bitmap_nr; i++)
+				tmp[i] |= bitmap[i];
+			if (memcmp(tmp, *refs, bitmap_size)) {
+				*refs = paint_alloc(info);
+				memcpy(*refs, tmp, bitmap_size);
+			}
+		}
+
+		if (c->object.flags & BOTTOM)
+			continue;
+
+		if (parse_commit(c))
+			die("unable to parse commit %s",
+			    oid_to_hex(&c->object.oid));
+
+		for (p = c->parents; p; p = p->next) {
+			if (p->item->object.flags & SEEN)
+				continue;
+			commit_list_insert(p->item, &head);
+		}
+	}
+
+	nr = get_max_object_index();
+	for (i = 0; i < nr; i++) {
+		struct object *o = get_indexed_object(i);
+		if (o && o->type == OBJ_COMMIT)
+			o->flags &= ~SEEN;
+	}
+
+	free(tmp);
+}
+
+static int mark_uninteresting(const char *refname, const struct object_id *oid,
+			      int flags, void *cb_data)
+{
+	struct commit *commit = lookup_commit_reference_gently(the_repository,
+							       oid, 1);
+	if (!commit)
+		return 0;
+	commit->object.flags |= UNINTERESTING;
+	mark_parents_uninteresting(commit);
+	return 0;
+}
+
+static void post_assign_shallow(struct shallow_info *info,
+				struct ref_bitmap *ref_bitmap,
+				int *ref_status);
+/*
+ * Step 6(+7), associate shallow commits with new refs
+ *
+ * info->ref must be initialized before calling this function.
+ *
+ * If used is not NULL, it's an array of info->shallow->nr
+ * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
+ * m-th shallow commit from info->shallow.
+ *
+ * If used is NULL, "ours" and "theirs" are updated. And if ref_status
+ * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
+ * the ref needs some shallow commits from either info->ours or
+ * info->theirs.
+ */
+void assign_shallow_commits_to_refs(struct shallow_info *info,
+				    uint32_t **used, int *ref_status)
+{
+	struct object_id *oid = info->shallow->oid;
+	struct oid_array *ref = info->ref;
+	unsigned int i, nr;
+	int *shallow, nr_shallow = 0;
+	struct paint_info pi;
+
+	trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
+	ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
+	for (i = 0; i < info->nr_ours; i++)
+		shallow[nr_shallow++] = info->ours[i];
+	for (i = 0; i < info->nr_theirs; i++)
+		shallow[nr_shallow++] = info->theirs[i];
+
+	/*
+	 * Prepare the commit graph to track what refs can reach what
+	 * (new) shallow commits.
+	 */
+	nr = get_max_object_index();
+	for (i = 0; i < nr; i++) {
+		struct object *o = get_indexed_object(i);
+		if (!o || o->type != OBJ_COMMIT)
+			continue;
+
+		o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
+	}
+
+	memset(&pi, 0, sizeof(pi));
+	init_ref_bitmap(&pi.ref_bitmap);
+	pi.nr_bits = ref->nr;
+
+	/*
+	 * "--not --all" to cut short the traversal if new refs
+	 * connect to old refs. If not (e.g. force ref updates) it'll
+	 * have to go down to the current shallow commits.
+	 */
+	head_ref(mark_uninteresting, NULL);
+	for_each_ref(mark_uninteresting, NULL);
+
+	/* Mark potential bottoms so we won't go out of bound */
+	for (i = 0; i < nr_shallow; i++) {
+		struct commit *c = lookup_commit(the_repository,
+						 &oid[shallow[i]]);
+		c->object.flags |= BOTTOM;
+	}
+
+	for (i = 0; i < ref->nr; i++)
+		paint_down(&pi, ref->oid + i, i);
+
+	if (used) {
+		int bitmap_size = DIV_ROUND_UP(pi.nr_bits, 32) * sizeof(uint32_t);
+		memset(used, 0, sizeof(*used) * info->shallow->nr);
+		for (i = 0; i < nr_shallow; i++) {
+			const struct commit *c = lookup_commit(the_repository,
+							       &oid[shallow[i]]);
+			uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
+			if (*map)
+				used[shallow[i]] = xmemdupz(*map, bitmap_size);
+		}
+		/*
+		 * unreachable shallow commits are not removed from
+		 * "ours" and "theirs". The user is supposed to run
+		 * step 7 on every ref separately and not trust "ours"
+		 * and "theirs" any more.
+		 */
+	} else
+		post_assign_shallow(info, &pi.ref_bitmap, ref_status);
+
+	clear_ref_bitmap(&pi.ref_bitmap);
+	for (i = 0; i < pi.pool_count; i++)
+		free(pi.pools[i]);
+	free(pi.pools);
+	free(shallow);
+}
+
+struct commit_array {
+	struct commit **commits;
+	int nr, alloc;
+};
+
+static int add_ref(const char *refname, const struct object_id *oid,
+		   int flags, void *cb_data)
+{
+	struct commit_array *ca = cb_data;
+	ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
+	ca->commits[ca->nr] = lookup_commit_reference_gently(the_repository,
+							     oid, 1);
+	if (ca->commits[ca->nr])
+		ca->nr++;
+	return 0;
+}
+
+static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
+{
+	unsigned int i;
+	if (!ref_status)
+		return;
+	for (i = 0; i < nr; i++)
+		if (bitmap[i / 32] & (1U << (i % 32)))
+			ref_status[i]++;
+}
+
+/*
+ * Step 7, reachability test on "ours" at commit level
+ */
+static void post_assign_shallow(struct shallow_info *info,
+				struct ref_bitmap *ref_bitmap,
+				int *ref_status)
+{
+	struct object_id *oid = info->shallow->oid;
+	struct commit *c;
+	uint32_t **bitmap;
+	int dst, i, j;
+	int bitmap_nr = DIV_ROUND_UP(info->ref->nr, 32);
+	struct commit_array ca;
+
+	trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
+	if (ref_status)
+		memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
+
+	/* Remove unreachable shallow commits from "theirs" */
+	for (i = dst = 0; i < info->nr_theirs; i++) {
+		if (i != dst)
+			info->theirs[dst] = info->theirs[i];
+		c = lookup_commit(the_repository, &oid[info->theirs[i]]);
+		bitmap = ref_bitmap_at(ref_bitmap, c);
+		if (!*bitmap)
+			continue;
+		for (j = 0; j < bitmap_nr; j++)
+			if (bitmap[0][j]) {
+				update_refstatus(ref_status, info->ref->nr, *bitmap);
+				dst++;
+				break;
+			}
+	}
+	info->nr_theirs = dst;
+
+	memset(&ca, 0, sizeof(ca));
+	head_ref(add_ref, &ca);
+	for_each_ref(add_ref, &ca);
+
+	/* Remove unreachable shallow commits from "ours" */
+	for (i = dst = 0; i < info->nr_ours; i++) {
+		if (i != dst)
+			info->ours[dst] = info->ours[i];
+		c = lookup_commit(the_repository, &oid[info->ours[i]]);
+		bitmap = ref_bitmap_at(ref_bitmap, c);
+		if (!*bitmap)
+			continue;
+		for (j = 0; j < bitmap_nr; j++)
+			if (bitmap[0][j] &&
+			    /* Step 7, reachability test at commit level */
+			    !in_merge_bases_many(c, ca.nr, ca.commits)) {
+				update_refstatus(ref_status, info->ref->nr, *bitmap);
+				dst++;
+				break;
+			}
+	}
+	info->nr_ours = dst;
+
+	free(ca.commits);
+}
+
+/* (Delayed) step 7, reachability test at commit level */
+int delayed_reachability_test(struct shallow_info *si, int c)
+{
+	if (si->need_reachability_test[c]) {
+		struct commit *commit = lookup_commit(the_repository,
+						      &si->shallow->oid[c]);
+
+		if (!si->commits) {
+			struct commit_array ca;
+
+			memset(&ca, 0, sizeof(ca));
+			head_ref(add_ref, &ca);
+			for_each_ref(add_ref, &ca);
+			si->commits = ca.commits;
+			si->nr_commits = ca.nr;
+		}
+
+		si->reachable[c] = in_merge_bases_many(commit,
+						       si->nr_commits,
+						       si->commits);
+		si->need_reachability_test[c] = 0;
+	}
+	return si->reachable[c];
+}