+#define SEEN (1u << 0)
+#define INTERESTING (1u << 1)
+#define COUNTED (1u << 2)
+#define SHOWN (1u << 3)
+
+static const char rev_list_usage[] =
+ "usage: git-rev-list [OPTION] commit-id <commit-id>\n"
+ " --max-count=nr\n"
+ " --max-age=epoch\n"
+ " --min-age=epoch\n"
+ " --bisect\n"
+ " --objects\n"
+ " --unpacked\n"
+ " --header\n"
+ " --pretty\n"
+ " --merge-order [ --show-breaks ]";
+
+static int unpacked = 0;
+static int bisect_list = 0;
+static int tag_objects = 0;
+static int tree_objects = 0;
+static int blob_objects = 0;
+static int verbose_header = 0;
+static int show_parents = 0;
+static int hdr_termination = 0;
+static const char *prefix = "";
+static unsigned long max_age = -1;
+static unsigned long min_age = -1;
+static int max_count = -1;
+static enum cmit_fmt commit_format = CMIT_FMT_RAW;
+static int merge_order = 0;
+static int show_breaks = 0;
+static int stop_traversal = 0;
+static int topo_order = 0;
+
+static void show_commit(struct commit *commit)
+{
+ commit->object.flags |= SHOWN;
+ if (show_breaks) {
+ prefix = "| ";
+ if (commit->object.flags & DISCONTINUITY) {
+ prefix = "^ ";
+ } else if (commit->object.flags & BOUNDARY) {
+ prefix = "= ";
+ }
+ }
+ printf("%s%s", prefix, sha1_to_hex(commit->object.sha1));
+ if (show_parents) {
+ struct commit_list *parents = commit->parents;
+ while (parents) {
+ printf(" %s", sha1_to_hex(parents->item->object.sha1));
+ parents = parents->next;
+ }
+ }
+ putchar('\n');
+ if (verbose_header) {
+ static char pretty_header[16384];
+ pretty_print_commit(commit_format, commit->buffer, ~0, pretty_header, sizeof(pretty_header));
+ printf("%s%c", pretty_header, hdr_termination);
+ }
+ fflush(stdout);
+}
+
+static int filter_commit(struct commit * commit)
+{
+ if (stop_traversal && (commit->object.flags & BOUNDARY))
+ return STOP;
+ if (commit->object.flags & (UNINTERESTING|SHOWN))
+ return CONTINUE;
+ if (min_age != -1 && (commit->date > min_age))
+ return CONTINUE;
+ if (max_age != -1 && (commit->date < max_age)) {
+ stop_traversal=1;
+ return merge_order?CONTINUE:STOP;
+ }
+ if (max_count != -1 && !max_count--)
+ return STOP;
+ return DO;
+}
+
+static int process_commit(struct commit * commit)
+{
+ int action=filter_commit(commit);
+
+ if (action == STOP) {
+ return STOP;
+ }
+
+ if (action == CONTINUE) {
+ return CONTINUE;
+ }
+
+ show_commit(commit);
+
+ return CONTINUE;
+}
+
+static struct object_list **add_object(struct object *obj, struct object_list **p, const char *name)
+{
+ struct object_list *entry = xmalloc(sizeof(*entry));
+ entry->item = obj;
+ entry->next = *p;
+ entry->name = name;
+ *p = entry;
+ return &entry->next;
+}
+
+static struct object_list **process_blob(struct blob *blob, struct object_list **p, const char *name)
+{
+ struct object *obj = &blob->object;
+
+ if (!blob_objects)
+ return p;
+ if (obj->flags & (UNINTERESTING | SEEN))
+ return p;
+ obj->flags |= SEEN;
+ return add_object(obj, p, name);
+}
+
+static struct object_list **process_tree(struct tree *tree, struct object_list **p, const char *name)
+{
+ struct object *obj = &tree->object;
+ struct tree_entry_list *entry;
+
+ if (!tree_objects)
+ return p;
+ if (obj->flags & (UNINTERESTING | SEEN))
+ return p;
+ if (parse_tree(tree) < 0)
+ die("bad tree object %s", sha1_to_hex(obj->sha1));
+ obj->flags |= SEEN;
+ p = add_object(obj, p, name);
+ for (entry = tree->entries ; entry ; entry = entry->next) {
+ if (entry->directory)
+ p = process_tree(entry->item.tree, p, entry->name);
+ else
+ p = process_blob(entry->item.blob, p, entry->name);
+ }
+ return p;
+}
+
+static struct object_list *pending_objects = NULL;
+
+static void show_commit_list(struct commit_list *list)
+{
+ struct object_list *objects = NULL, **p = &objects, *pending;
+ while (list) {
+ struct commit *commit = pop_most_recent_commit(&list, SEEN);
+
+ p = process_tree(commit->tree, p, "");
+ if (process_commit(commit) == STOP)
+ break;
+ }
+ for (pending = pending_objects; pending; pending = pending->next) {
+ struct object *obj = pending->item;
+ const char *name = pending->name;
+ if (obj->flags & (UNINTERESTING | SEEN))
+ continue;
+ if (obj->type == tag_type) {
+ obj->flags |= SEEN;
+ p = add_object(obj, p, name);
+ continue;
+ }
+ if (obj->type == tree_type) {
+ p = process_tree((struct tree *)obj, p, name);
+ continue;
+ }
+ if (obj->type == blob_type) {
+ p = process_blob((struct blob *)obj, p, name);
+ continue;
+ }
+ die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
+ }
+ while (objects) {
+ printf("%s %s\n", sha1_to_hex(objects->item->sha1), objects->name);
+ objects = objects->next;
+ }
+}
+
+static void mark_blob_uninteresting(struct blob *blob)
+{
+ if (!blob_objects)
+ return;
+ if (blob->object.flags & UNINTERESTING)
+ return;
+ blob->object.flags |= UNINTERESTING;
+}
+
+static void mark_tree_uninteresting(struct tree *tree)
+{
+ struct object *obj = &tree->object;
+ struct tree_entry_list *entry;
+
+ if (!tree_objects)
+ return;
+ if (obj->flags & UNINTERESTING)
+ return;
+ obj->flags |= UNINTERESTING;
+ if (!has_sha1_file(obj->sha1))
+ return;
+ if (parse_tree(tree) < 0)
+ die("bad tree %s", sha1_to_hex(obj->sha1));
+ entry = tree->entries;
+ while (entry) {
+ if (entry->directory)
+ mark_tree_uninteresting(entry->item.tree);
+ else
+ mark_blob_uninteresting(entry->item.blob);
+ entry = entry->next;
+ }
+}
+
+static void mark_parents_uninteresting(struct commit *commit)
+{
+ struct commit_list *parents = commit->parents;
+
+ if (tree_objects)
+ mark_tree_uninteresting(commit->tree);
+ while (parents) {
+ struct commit *commit = parents->item;
+ commit->object.flags |= UNINTERESTING;
+
+ /*
+ * A missing commit is ok iff its parent is marked
+ * uninteresting.
+ *
+ * We just mark such a thing parsed, so that when
+ * it is popped next time around, we won't be trying
+ * to parse it and get an error.
+ */
+ if (!has_sha1_file(commit->object.sha1))
+ commit->object.parsed = 1;
+ parents = parents->next;
+ }
+}
+
+static int everybody_uninteresting(struct commit_list *list)
+{
+ while (list) {
+ struct commit *commit = list->item;
+ list = list->next;
+ if (commit->object.flags & UNINTERESTING)
+ continue;
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * This is a truly stupid algorithm, but it's only
+ * used for bisection, and we just don't care enough.
+ *
+ * We care just barely enough to avoid recursing for
+ * non-merge entries.
+ */
+static int count_distance(struct commit_list *entry)
+{
+ int nr = 0;
+
+ while (entry) {
+ struct commit *commit = entry->item;
+ struct commit_list *p;
+
+ if (commit->object.flags & (UNINTERESTING | COUNTED))
+ break;
+ nr++;
+ commit->object.flags |= COUNTED;
+ p = commit->parents;
+ entry = p;
+ if (p) {
+ p = p->next;
+ while (p) {
+ nr += count_distance(p);
+ p = p->next;
+ }
+ }
+ }
+ return nr;
+}
+
+static void clear_distance(struct commit_list *list)
+{
+ while (list) {
+ struct commit *commit = list->item;
+ commit->object.flags &= ~COUNTED;
+ list = list->next;
+ }
+}
+
+static struct commit_list *find_bisection(struct commit_list *list)
+{
+ int nr, closest;
+ struct commit_list *p, *best;
+
+ nr = 0;
+ p = list;
+ while (p) {
+ nr++;
+ p = p->next;
+ }
+ closest = 0;
+ best = list;
+
+ p = list;
+ while (p) {
+ int distance = count_distance(p);
+ clear_distance(list);
+ if (nr - distance < distance)
+ distance = nr - distance;
+ if (distance > closest) {
+ best = p;
+ closest = distance;
+ }
+ p = p->next;
+ }
+ if (best)
+ best->next = NULL;
+ return best;
+}
+
+static struct commit_list *limit_list(struct commit_list *list)
+{
+ struct commit_list *newlist = NULL;
+ struct commit_list **p = &newlist;
+ while (list) {
+ struct commit *commit = pop_most_recent_commit(&list, SEEN);
+ struct object *obj = &commit->object;
+
+ if (unpacked && has_sha1_pack(obj->sha1))
+ obj->flags |= UNINTERESTING;
+ if (obj->flags & UNINTERESTING) {
+ mark_parents_uninteresting(commit);
+ if (everybody_uninteresting(list))
+ break;
+ continue;
+ }
+ p = &commit_list_insert(commit, p)->next;
+ }
+ if (bisect_list)
+ newlist = find_bisection(newlist);
+ return newlist;
+}
+
+static void add_pending_object(struct object *obj, const char *name)
+{
+ add_object(obj, &pending_objects, name);
+}
+
+static struct commit *get_commit_reference(const char *name, unsigned int flags)