-#define TREE_SAME 0
-#define TREE_NEW 1
-#define TREE_DIFFERENT 2
-static int tree_difference = TREE_SAME;
-
-static void file_add_remove(struct diff_options *options,
- int addremove, unsigned mode,
- const unsigned char *sha1,
- const char *base, const char *path)
-{
- int diff = TREE_DIFFERENT;
-
- /*
- * Is it an add of a new file? It means that
- * the old tree didn't have it at all, so we
- * will turn "TREE_SAME" -> "TREE_NEW", but
- * leave any "TREE_DIFFERENT" alone (and if
- * it already was "TREE_NEW", we'll keep it
- * "TREE_NEW" of course).
- */
- if (addremove == '+') {
- diff = tree_difference;
- if (diff != TREE_SAME)
- return;
- diff = TREE_NEW;
- }
- tree_difference = diff;
-}
-
-static void file_change(struct diff_options *options,
- unsigned old_mode, unsigned new_mode,
- const unsigned char *old_sha1,
- const unsigned char *new_sha1,
- const char *base, const char *path)
-{
- tree_difference = TREE_DIFFERENT;
-}
-
-static struct diff_options diff_opt = {
- .recursive = 1,
- .add_remove = file_add_remove,
- .change = file_change,
-};
-
-static int compare_tree(struct tree *t1, struct tree *t2)
-{
- if (!t1)
- return TREE_NEW;
- if (!t2)
- return TREE_DIFFERENT;
- tree_difference = TREE_SAME;
- if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
- return TREE_DIFFERENT;
- return tree_difference;
-}
-
-static int same_tree_as_empty(struct tree *t1)
-{
- int retval;
- void *tree;
- struct tree_desc empty, real;
-
- if (!t1)
- return 0;
-
- tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
- if (!tree)
- return 0;
- real.buf = tree;
-
- empty.buf = "";
- empty.size = 0;
-
- tree_difference = 0;
- retval = diff_tree(&empty, &real, "", &diff_opt);
- free(tree);
-
- return retval >= 0 && !tree_difference;
-}
-
-static void try_to_simplify_commit(struct commit *commit)
-{
- struct commit_list **pp, *parent;
-
- if (!commit->tree)
- return;
-
- if (!commit->parents) {
- if (!same_tree_as_empty(commit->tree))
- commit->object.flags |= TREECHANGE;
- return;
- }
-
- pp = &commit->parents;
- while ((parent = *pp) != NULL) {
- struct commit *p = parent->item;
-
- if (p->object.flags & UNINTERESTING) {
- pp = &parent->next;
- continue;
- }
-
- parse_commit(p);
- switch (compare_tree(p->tree, commit->tree)) {
- case TREE_SAME:
- parent->next = NULL;
- commit->parents = parent;
- return;
-
- case TREE_NEW:
- if (revs.remove_empty_trees && same_tree_as_empty(p->tree)) {
- *pp = parent->next;
- continue;
- }
- /* fallthrough */
- case TREE_DIFFERENT:
- pp = &parent->next;
- continue;
- }
- die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
- }
- commit->object.flags |= TREECHANGE;
-}
-
-static void add_parents_to_list(struct commit *commit, struct commit_list **list)
-{
- struct commit_list *parent = commit->parents;
-
- /*
- * If the commit is uninteresting, don't try to
- * prune parents - we want the maximal uninteresting
- * set.
- *
- * Normally we haven't parsed the parent
- * yet, so we won't have a parent of a parent
- * here. However, it may turn out that we've
- * reached this commit some other way (where it
- * wasn't uninteresting), in which case we need
- * to mark its parents recursively too..
- */
- if (commit->object.flags & UNINTERESTING) {
- while (parent) {
- struct commit *p = parent->item;
- parent = parent->next;
- parse_commit(p);
- p->object.flags |= UNINTERESTING;
- if (p->parents)
- mark_parents_uninteresting(p);
- if (p->object.flags & SEEN)
- continue;
- p->object.flags |= SEEN;
- insert_by_date(p, list);
- }
- return;
- }
-
- /*
- * Ok, the commit wasn't uninteresting. Try to
- * simplify the commit history and find the parent
- * that has no differences in the path set if one exists.
- */
- if (revs.paths)
- try_to_simplify_commit(commit);
-
- parent = commit->parents;
- while (parent) {
- struct commit *p = parent->item;
-
- parent = parent->next;
-
- parse_commit(p);
- if (p->object.flags & SEEN)
- continue;
- p->object.flags |= SEEN;
- insert_by_date(p, list);
- }
-}
-
-static struct commit_list *limit_list(struct commit_list *list)
-{
- struct commit_list *newlist = NULL;
- struct commit_list **p = &newlist;
- while (list) {
- struct commit_list *entry = list;
- struct commit *commit = list->item;
- struct object *obj = &commit->object;
-
- list = list->next;
- free(entry);
-
- if (revs.max_age != -1 && (commit->date < revs.max_age))
- obj->flags |= UNINTERESTING;
- if (revs.unpacked && has_sha1_pack(obj->sha1))
- obj->flags |= UNINTERESTING;
- add_parents_to_list(commit, &list);
- if (obj->flags & UNINTERESTING) {
- mark_parents_uninteresting(commit);
- if (everybody_uninteresting(list))
- break;
- continue;
- }
- if (revs.min_age != -1 && (commit->date > revs.min_age))
- continue;
- p = &commit_list_insert(commit, p)->next;
- }
- if (revs.tree_objects)
- mark_edges_uninteresting(newlist);
- if (bisect_list)
- newlist = find_bisection(newlist);
- return newlist;
-}
-