This source file includes following definitions.
- lookup_commit_reference_gently
 
- lookup_commit_reference
 
- lookup_commit_or_die
 
- lookup_commit
 
- lookup_commit_reference_by_name
 
- parse_commit_date
 
- commit_graft_sha1_access
 
- commit_graft_pos
 
- register_commit_graft
 
- read_graft_line
 
- read_graft_file
 
- prepare_commit_graft
 
- lookup_commit_graft
 
- for_each_commit_graft
 
- unregister_shallow
 
- set_commit_buffer
 
- get_cached_commit_buffer
 
- get_commit_buffer
 
- unuse_commit_buffer
 
- free_commit_buffer
 
- detach_commit_buffer
 
- parse_commit_buffer
 
- parse_commit_gently
 
- parse_commit_or_die
 
- find_commit_subject
 
- commit_list_insert
 
- commit_list_count
 
- copy_commit_list
 
- free_commit_list
 
- commit_list_insert_by_date
 
- commit_list_compare_by_date
 
- commit_list_get_next
 
- commit_list_set_next
 
- commit_list_sort_by_date
 
- pop_most_recent_commit
 
- clear_commit_marks_1
 
- clear_commit_marks_many
 
- clear_commit_marks
 
- clear_commit_marks_for_object_array
 
- pop_commit
 
- record_author_date
 
- compare_commits_by_author_date
 
- compare_commits_by_commit_date
 
- sort_in_topological_order
 
- queue_has_nonstale
 
- paint_down_to_common
 
- merge_bases_many
 
- get_octopus_merge_bases
 
- remove_redundant
 
- get_merge_bases_many_0
 
- get_merge_bases_many
 
- get_merge_bases_many_dirty
 
- get_merge_bases
 
- is_descendant_of
 
- in_merge_bases_many
 
- in_merge_bases
 
- reduce_heads
 
- do_sign_commit
 
- parse_signed_commit
 
- remove_signature
 
- handle_signed_tag
 
- check_commit_signature
 
- append_merge_tag_headers
 
- add_extra_header
 
- read_commit_extra_headers
 
- for_each_mergetag
 
- standard_header_field
 
- excluded_header_field
 
- read_commit_extra_header_lines
 
- free_commit_extra_headers
 
- commit_tree
 
- find_invalid_utf8
 
- verify_utf8
 
- commit_tree_extended
 
- get_merge_parent
 
- commit_list_append
 
- print_commit_list
 
- find_commit_header
 
- ignore_non_trailer
 
#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "pkt-line.h"
#include "utf8.h"
#include "diff.h"
#include "revision.h"
#include "notes.h"
#include "gpg-interface.h"
#include "mergesort.h"
#include "commit-slab.h"
#include "prio-queue.h"
#include "sha1-lookup.h"
static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
int save_commit_buffer = 1;
const char *commit_type = "commit";
struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
                                              int quiet)
{
        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
        if (!obj)
                return NULL;
        return object_as_type(obj, OBJ_COMMIT, quiet);
}
struct commit *lookup_commit_reference(const unsigned char *sha1)
{
        return lookup_commit_reference_gently(sha1, 0);
}
struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
{
        struct commit *c = lookup_commit_reference(sha1);
        if (!c)
                die(_("could not parse %s"), ref_name);
        if (hashcmp(sha1, c->object.sha1)) {
                warning(_("%s %s is not a commit!"),
                        ref_name, sha1_to_hex(sha1));
        }
        return c;
}
struct commit *lookup_commit(const unsigned char *sha1)
{
        struct object *obj = lookup_object(sha1);
        if (!obj)
                return create_object(sha1, alloc_commit_node());
        return object_as_type(obj, OBJ_COMMIT, 0);
}
struct commit *lookup_commit_reference_by_name(const char *name)
{
        struct object_id oid;
        struct commit *commit;
        if (get_sha1_committish(name, oid.hash))
                return NULL;
        commit = lookup_commit_reference(oid.hash);
        if (parse_commit(commit))
                return NULL;
        return commit;
}
static unsigned long parse_commit_date(const char *buf, const char *tail)
{
        const char *dateptr;
        if (buf + 6 >= tail)
                return 0;
        if (memcmp(buf, "author", 6))
                return 0;
        while (buf < tail && *buf++ != '\n')
                ;
        if (buf + 9 >= tail)
                return 0;
        if (memcmp(buf, "committer", 9))
                return 0;
        while (buf < tail && *buf++ != '>')
                ;
        if (buf >= tail)
                return 0;
        dateptr = buf;
        while (buf < tail && *buf++ != '\n')
                ;
        if (buf >= tail)
                return 0;
        
        return strtoul(dateptr, NULL, 10);
}
static struct commit_graft **commit_graft;
static int commit_graft_alloc, commit_graft_nr;
static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
{
        struct commit_graft **commit_graft_table = table;
        return commit_graft_table[index]->oid.hash;
}
static int commit_graft_pos(const unsigned char *sha1)
{
        return sha1_pos(sha1, commit_graft, commit_graft_nr,
                        commit_graft_sha1_access);
}
int register_commit_graft(struct commit_graft *graft, int ignore_dups)
{
        int pos = commit_graft_pos(graft->oid.hash);
        if (0 <= pos) {
                if (ignore_dups)
                        free(graft);
                else {
                        free(commit_graft[pos]);
                        commit_graft[pos] = graft;
                }
                return 1;
        }
        pos = -pos - 1;
        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
        commit_graft_nr++;
        if (pos < commit_graft_nr)
                memmove(commit_graft + pos + 1,
                        commit_graft + pos,
                        (commit_graft_nr - pos - 1) *
                        sizeof(*commit_graft));
        commit_graft[pos] = graft;
        return 0;
}
struct commit_graft *read_graft_line(char *buf, int len)
{
        
        int i;
        struct commit_graft *graft = NULL;
        const int entry_size = GIT_SHA1_HEXSZ + 1;
        while (len && isspace(buf[len-1]))
                buf[--len] = '\0';
        if (buf[0] == '#' || buf[0] == '\0')
                return NULL;
        if ((len + 1) % entry_size)
                goto bad_graft_data;
        i = (len + 1) / entry_size - 1;
        graft = xmalloc(sizeof(*graft) + GIT_SHA1_RAWSZ * i);
        graft->nr_parent = i;
        if (get_oid_hex(buf, &graft->oid))
                goto bad_graft_data;
        for (i = GIT_SHA1_HEXSZ; i < len; i += entry_size) {
                if (buf[i] != ' ')
                        goto bad_graft_data;
                if (get_sha1_hex(buf + i + 1, graft->parent[i/entry_size].hash))
                        goto bad_graft_data;
        }
        return graft;
bad_graft_data:
        error("bad graft data: %s", buf);
        free(graft);
        return NULL;
}
static int read_graft_file(const char *graft_file)
{
        FILE *fp = fopen(graft_file, "r");
        struct strbuf buf = STRBUF_INIT;
        if (!fp)
                return -1;
        while (!strbuf_getwholeline(&buf, fp, '\n')) {
                
                struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
                if (!graft)
                        continue;
                if (register_commit_graft(graft, 1))
                        error("duplicate graft data: %s", buf.buf);
        }
        fclose(fp);
        strbuf_release(&buf);
        return 0;
}
static void prepare_commit_graft(void)
{
        static int commit_graft_prepared;
        char *graft_file;
        if (commit_graft_prepared)
                return;
        graft_file = get_graft_file();
        read_graft_file(graft_file);
        
        is_repository_shallow();
        commit_graft_prepared = 1;
}
struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
{
        int pos;
        prepare_commit_graft();
        pos = commit_graft_pos(sha1);
        if (pos < 0)
                return NULL;
        return commit_graft[pos];
}
int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
{
        int i, ret;
        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
                ret = fn(commit_graft[i], cb_data);
        return ret;
}
int unregister_shallow(const unsigned char *sha1)
{
        int pos = commit_graft_pos(sha1);
        if (pos < 0)
                return -1;
        if (pos + 1 < commit_graft_nr)
                memmove(commit_graft + pos, commit_graft + pos + 1,
                                sizeof(struct commit_graft *)
                                * (commit_graft_nr - pos - 1));
        commit_graft_nr--;
        return 0;
}
struct commit_buffer {
        void *buffer;
        unsigned long size;
};
define_commit_slab(buffer_slab, struct commit_buffer);
static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
{
        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
        v->buffer = buffer;
        v->size = size;
}
const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
{
        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
        if (!v) {
                if (sizep)
                        *sizep = 0;
                return NULL;
        }
        if (sizep)
                *sizep = v->size;
        return v->buffer;
}
const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
{
        const void *ret = get_cached_commit_buffer(commit, sizep);
        if (!ret) {
                enum object_type type;
                unsigned long size;
                ret = read_sha1_file(commit->object.sha1, &type, &size);
                if (!ret)
                        die("cannot read commit object %s",
                            sha1_to_hex(commit->object.sha1));
                if (type != OBJ_COMMIT)
                        die("expected commit for %s, got %s",
                            sha1_to_hex(commit->object.sha1), typename(type));
                if (sizep)
                        *sizep = size;
        }
        return ret;
}
void unuse_commit_buffer(const struct commit *commit, const void *buffer)
{
        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
        if (!(v && v->buffer == buffer))
                free((void *)buffer);
}
void free_commit_buffer(struct commit *commit)
{
        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
        if (v) {
                free(v->buffer);
                v->buffer = NULL;
                v->size = 0;
        }
}
const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
{
        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
        void *ret;
        if (!v) {
                if (sizep)
                        *sizep = 0;
                return NULL;
        }
        ret = v->buffer;
        if (sizep)
                *sizep = v->size;
        v->buffer = NULL;
        v->size = 0;
        return ret;
}
int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
{
        const char *tail = buffer;
        const char *bufptr = buffer;
        struct object_id parent;
        struct commit_list **pptr;
        struct commit_graft *graft;
        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
        if (item->object.parsed)
                return 0;
        item->object.parsed = 1;
        tail += size;
        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
                        bufptr[tree_entry_len] != '\n')
                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
                return error("bad tree pointer in commit %s",
                             sha1_to_hex(item->object.sha1));
        item->tree = lookup_tree(parent.hash);
        bufptr += tree_entry_len + 1; 
        pptr = &item->parents;
        graft = lookup_commit_graft(item->object.sha1);
        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
                struct commit *new_parent;
                if (tail <= bufptr + parent_entry_len + 1 ||
                    get_sha1_hex(bufptr + 7, parent.hash) ||
                    bufptr[parent_entry_len] != '\n')
                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
                bufptr += parent_entry_len + 1;
                
                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
                        continue;
                new_parent = lookup_commit(parent.hash);
                if (new_parent)
                        pptr = &commit_list_insert(new_parent, pptr)->next;
        }
        if (graft) {
                int i;
                struct commit *new_parent;
                for (i = 0; i < graft->nr_parent; i++) {
                        new_parent = lookup_commit(graft->parent[i].hash);
                        if (!new_parent)
                                continue;
                        pptr = &commit_list_insert(new_parent, pptr)->next;
                }
        }
        item->date = parse_commit_date(bufptr, tail);
        return 0;
}
int parse_commit_gently(struct commit *item, int quiet_on_missing)
{
        enum object_type type;
        void *buffer;
        unsigned long size;
        int ret;
        if (!item)
                return -1;
        if (item->object.parsed)
                return 0;
        buffer = read_sha1_file(item->object.sha1, &type, &size);
        if (!buffer)
                return quiet_on_missing ? -1 :
                        error("Could not read %s",
                             sha1_to_hex(item->object.sha1));
        if (type != OBJ_COMMIT) {
                free(buffer);
                return error("Object %s not a commit",
                             sha1_to_hex(item->object.sha1));
        }
        ret = parse_commit_buffer(item, buffer, size);
        if (save_commit_buffer && !ret) {
                set_commit_buffer(item, buffer, size);
                return 0;
        }
        free(buffer);
        return ret;
}
void parse_commit_or_die(struct commit *item)
{
        if (parse_commit(item))
                die("unable to parse commit %s",
                    item ? sha1_to_hex(item->object.sha1) : "(null)");
}
int find_commit_subject(const char *commit_buffer, const char **subject)
{
        const char *eol;
        const char *p = commit_buffer;
        while (*p && (*p != '\n' || p[1] != '\n'))
                p++;
        if (*p) {
                p += 2;
                for (eol = p; *eol && *eol != '\n'; eol++)
                        ; 
        } else
                eol = p;
        *subject = p;
        return eol - p;
}
struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
{
        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
        new_list->item = item;
        new_list->next = *list_p;
        *list_p = new_list;
        return new_list;
}
unsigned commit_list_count(const struct commit_list *l)
{
        unsigned c = 0;
        for (; l; l = l->next )
                c++;
        return c;
}
struct commit_list *copy_commit_list(struct commit_list *list)
{
        struct commit_list *head = NULL;
        struct commit_list **pp = &head;
        while (list) {
                pp = commit_list_append(list->item, pp);
                list = list->next;
        }
        return head;
}
void free_commit_list(struct commit_list *list)
{
        while (list) {
                struct commit_list *temp = list;
                list = temp->next;
                free(temp);
        }
}
struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
{
        struct commit_list **pp = list;
        struct commit_list *p;
        while ((p = *pp) != NULL) {
                if (p->item->date < item->date) {
                        break;
                }
                pp = &p->next;
        }
        return commit_list_insert(item, pp);
}
static int commit_list_compare_by_date(const void *a, const void *b)
{
        unsigned long a_date = ((const struct commit_list *)a)->item->date;
        unsigned long b_date = ((const struct commit_list *)b)->item->date;
        if (a_date < b_date)
                return 1;
        if (a_date > b_date)
                return -1;
        return 0;
}
static void *commit_list_get_next(const void *a)
{
        return ((const struct commit_list *)a)->next;
}
static void commit_list_set_next(void *a, void *next)
{
        ((struct commit_list *)a)->next = next;
}
void commit_list_sort_by_date(struct commit_list **list)
{
        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
                                commit_list_compare_by_date);
}
struct commit *pop_most_recent_commit(struct commit_list **list,
                                      unsigned int mark)
{
        struct commit *ret = (*list)->item;
        struct commit_list *parents = ret->parents;
        struct commit_list *old = *list;
        *list = (*list)->next;
        free(old);
        while (parents) {
                struct commit *commit = parents->item;
                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
                        commit->object.flags |= mark;
                        commit_list_insert_by_date(commit, list);
                }
                parents = parents->next;
        }
        return ret;
}
static void clear_commit_marks_1(struct commit_list **plist,
                                 struct commit *commit, unsigned int mark)
{
        while (commit) {
                struct commit_list *parents;
                if (!(mark & commit->object.flags))
                        return;
                commit->object.flags &= ~mark;
                parents = commit->parents;
                if (!parents)
                        return;
                while ((parents = parents->next))
                        commit_list_insert(parents->item, plist);
                commit = commit->parents->item;
        }
}
void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
{
        struct commit_list *list = NULL;
        while (nr--) {
                commit_list_insert(*commit, &list);
                commit++;
        }
        while (list)
                clear_commit_marks_1(&list, pop_commit(&list), mark);
}
void clear_commit_marks(struct commit *commit, unsigned int mark)
{
        clear_commit_marks_many(1, &commit, mark);
}
void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
{
        struct object *object;
        struct commit *commit;
        unsigned int i;
        for (i = 0; i < a->nr; i++) {
                object = a->objects[i].item;
                commit = lookup_commit_reference_gently(object->sha1, 1);
                if (commit)
                        clear_commit_marks(commit, mark);
        }
}
struct commit *pop_commit(struct commit_list **stack)
{
        struct commit_list *top = *stack;
        struct commit *item = top ? top->item : NULL;
        if (top) {
                *stack = top->next;
                free(top);
        }
        return item;
}
define_commit_slab(indegree_slab, int);
define_commit_slab(author_date_slab, unsigned long);
static void record_author_date(struct author_date_slab *author_date,
                               struct commit *commit)
{
        const char *buffer = get_commit_buffer(commit, NULL);
        struct ident_split ident;
        const char *ident_line;
        size_t ident_len;
        char *date_end;
        unsigned long date;
        ident_line = find_commit_header(buffer, "author", &ident_len);
        if (!ident_line)
                goto fail_exit; 
        if (split_ident_line(&ident, ident_line, ident_len) ||
            !ident.date_begin || !ident.date_end)
                goto fail_exit; 
        date = strtoul(ident.date_begin, &date_end, 10);
        if (date_end != ident.date_end)
                goto fail_exit; 
        *(author_date_slab_at(author_date, commit)) = date;
fail_exit:
        unuse_commit_buffer(commit, buffer);
}
static int compare_commits_by_author_date(const void *a_, const void *b_,
                                          void *cb_data)
{
        const struct commit *a = a_, *b = b_;
        struct author_date_slab *author_date = cb_data;
        unsigned long a_date = *(author_date_slab_at(author_date, a));
        unsigned long b_date = *(author_date_slab_at(author_date, b));
        
        if (a_date < b_date)
                return 1;
        else if (a_date > b_date)
                return -1;
        return 0;
}
int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
{
        const struct commit *a = a_, *b = b_;
        
        if (a->date < b->date)
                return 1;
        else if (a->date > b->date)
                return -1;
        return 0;
}
void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
{
        struct commit_list *next, *orig = *list;
        struct commit_list **pptr;
        struct indegree_slab indegree;
        struct prio_queue queue;
        struct commit *commit;
        struct author_date_slab author_date;
        if (!orig)
                return;
        *list = NULL;
        init_indegree_slab(&indegree);
        memset(&queue, '\0', sizeof(queue));
        switch (sort_order) {
        default: 
                queue.compare = NULL;
                break;
        case REV_SORT_BY_COMMIT_DATE:
                queue.compare = compare_commits_by_commit_date;
                break;
        case REV_SORT_BY_AUTHOR_DATE:
                init_author_date_slab(&author_date);
                queue.compare = compare_commits_by_author_date;
                queue.cb_data = &author_date;
                break;
        }
        
        for (next = orig; next; next = next->next) {
                struct commit *commit = next->item;
                *(indegree_slab_at(&indegree, commit)) = 1;
                
                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
                        record_author_date(&author_date, commit);
        }
        
        for (next = orig; next; next = next->next) {
                struct commit_list *parents = next->item->parents;
                while (parents) {
                        struct commit *parent = parents->item;
                        int *pi = indegree_slab_at(&indegree, parent);
                        if (*pi)
                                (*pi)++;
                        parents = parents->next;
                }
        }
        
        for (next = orig; next; next = next->next) {
                struct commit *commit = next->item;
                if (*(indegree_slab_at(&indegree, commit)) == 1)
                        prio_queue_put(&queue, commit);
        }
        
        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
                prio_queue_reverse(&queue);
        
        free_commit_list(orig);
        pptr = list;
        *list = NULL;
        while ((commit = prio_queue_get(&queue)) != NULL) {
                struct commit_list *parents;
                for (parents = commit->parents; parents ; parents = parents->next) {
                        struct commit *parent = parents->item;
                        int *pi = indegree_slab_at(&indegree, parent);
                        if (!*pi)
                                continue;
                        
                        if (--(*pi) == 1)
                                prio_queue_put(&queue, parent);
                }
                
                *(indegree_slab_at(&indegree, commit)) = 0;
                pptr = &commit_list_insert(commit, pptr)->next;
        }
        clear_indegree_slab(&indegree);
        clear_prio_queue(&queue);
        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
                clear_author_date_slab(&author_date);
}
#define PARENT1         (1u<<16)
#define PARENT2         (1u<<17)
#define STALE           (1u<<18)
#define RESULT          (1u<<19)
static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
static int queue_has_nonstale(struct prio_queue *queue)
{
        int i;
        for (i = 0; i < queue->nr; i++) {
                struct commit *commit = queue->array[i].data;
                if (!(commit->object.flags & STALE))
                        return 1;
        }
        return 0;
}
static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
{
        struct prio_queue queue = { compare_commits_by_commit_date };
        struct commit_list *result = NULL;
        int i;
        one->object.flags |= PARENT1;
        if (!n) {
                commit_list_append(one, &result);
                return result;
        }
        prio_queue_put(&queue, one);
        for (i = 0; i < n; i++) {
                twos[i]->object.flags |= PARENT2;
                prio_queue_put(&queue, twos[i]);
        }
        while (queue_has_nonstale(&queue)) {
                struct commit *commit = prio_queue_get(&queue);
                struct commit_list *parents;
                int flags;
                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
                if (flags == (PARENT1 | PARENT2)) {
                        if (!(commit->object.flags & RESULT)) {
                                commit->object.flags |= RESULT;
                                commit_list_insert_by_date(commit, &result);
                        }
                        
                        flags |= STALE;
                }
                parents = commit->parents;
                while (parents) {
                        struct commit *p = parents->item;
                        parents = parents->next;
                        if ((p->object.flags & flags) == flags)
                                continue;
                        if (parse_commit(p))
                                return NULL;
                        p->object.flags |= flags;
                        prio_queue_put(&queue, p);
                }
        }
        clear_prio_queue(&queue);
        return result;
}
static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
{
        struct commit_list *list = NULL;
        struct commit_list *result = NULL;
        int i;
        for (i = 0; i < n; i++) {
                if (one == twos[i])
                        
                        return commit_list_insert(one, &result);
        }
        if (parse_commit(one))
                return NULL;
        for (i = 0; i < n; i++) {
                if (parse_commit(twos[i]))
                        return NULL;
        }
        list = paint_down_to_common(one, n, twos);
        while (list) {
                struct commit_list *next = list->next;
                if (!(list->item->object.flags & STALE))
                        commit_list_insert_by_date(list->item, &result);
                free(list);
                list = next;
        }
        return result;
}
struct commit_list *get_octopus_merge_bases(struct commit_list *in)
{
        struct commit_list *i, *j, *k, *ret = NULL;
        if (!in)
                return ret;
        commit_list_insert(in->item, &ret);
        for (i = in->next; i; i = i->next) {
                struct commit_list *new = NULL, *end = NULL;
                for (j = ret; j; j = j->next) {
                        struct commit_list *bases;
                        bases = get_merge_bases(i->item, j->item);
                        if (!new)
                                new = bases;
                        else
                                end->next = bases;
                        for (k = bases; k; k = k->next)
                                end = k;
                }
                ret = new;
        }
        return ret;
}
static int remove_redundant(struct commit **array, int cnt)
{
        
        struct commit **work;
        unsigned char *redundant;
        int *filled_index;
        int i, j, filled;
        work = xcalloc(cnt, sizeof(*work));
        redundant = xcalloc(cnt, 1);
        filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
        for (i = 0; i < cnt; i++)
                parse_commit(array[i]);
        for (i = 0; i < cnt; i++) {
                struct commit_list *common;
                if (redundant[i])
                        continue;
                for (j = filled = 0; j < cnt; j++) {
                        if (i == j || redundant[j])
                                continue;
                        filled_index[filled] = j;
                        work[filled++] = array[j];
                }
                common = paint_down_to_common(array[i], filled, work);
                if (array[i]->object.flags & PARENT2)
                        redundant[i] = 1;
                for (j = 0; j < filled; j++)
                        if (work[j]->object.flags & PARENT1)
                                redundant[filled_index[j]] = 1;
                clear_commit_marks(array[i], all_flags);
                for (j = 0; j < filled; j++)
                        clear_commit_marks(work[j], all_flags);
                free_commit_list(common);
        }
        
        memcpy(work, array, sizeof(*array) * cnt);
        for (i = filled = 0; i < cnt; i++)
                if (!redundant[i])
                        array[filled++] = work[i];
        for (j = filled, i = 0; i < cnt; i++)
                if (redundant[i])
                        array[j++] = work[i];
        free(work);
        free(redundant);
        free(filled_index);
        return filled;
}
static struct commit_list *get_merge_bases_many_0(struct commit *one,
                                                  int n,
                                                  struct commit **twos,
                                                  int cleanup)
{
        struct commit_list *list;
        struct commit **rslt;
        struct commit_list *result;
        int cnt, i;
        result = merge_bases_many(one, n, twos);
        for (i = 0; i < n; i++) {
                if (one == twos[i])
                        return result;
        }
        if (!result || !result->next) {
                if (cleanup) {
                        clear_commit_marks(one, all_flags);
                        clear_commit_marks_many(n, twos, all_flags);
                }
                return result;
        }
        
        cnt = commit_list_count(result);
        rslt = xcalloc(cnt, sizeof(*rslt));
        for (list = result, i = 0; list; list = list->next)
                rslt[i++] = list->item;
        free_commit_list(result);
        clear_commit_marks(one, all_flags);
        clear_commit_marks_many(n, twos, all_flags);
        cnt = remove_redundant(rslt, cnt);
        result = NULL;
        for (i = 0; i < cnt; i++)
                commit_list_insert_by_date(rslt[i], &result);
        free(rslt);
        return result;
}
struct commit_list *get_merge_bases_many(struct commit *one,
                                         int n,
                                         struct commit **twos)
{
        return get_merge_bases_many_0(one, n, twos, 1);
}
struct commit_list *get_merge_bases_many_dirty(struct commit *one,
                                               int n,
                                               struct commit **twos)
{
        return get_merge_bases_many_0(one, n, twos, 0);
}
struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
{
        return get_merge_bases_many_0(one, 1, &two, 1);
}
int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
{
        if (!with_commit)
                return 1;
        while (with_commit) {
                struct commit *other;
                other = with_commit->item;
                with_commit = with_commit->next;
                if (in_merge_bases(other, commit))
                        return 1;
        }
        return 0;
}
int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
{
        struct commit_list *bases;
        int ret = 0, i;
        if (parse_commit(commit))
                return ret;
        for (i = 0; i < nr_reference; i++)
                if (parse_commit(reference[i]))
                        return ret;
        bases = paint_down_to_common(commit, nr_reference, reference);
        if (commit->object.flags & PARENT2)
                ret = 1;
        clear_commit_marks(commit, all_flags);
        clear_commit_marks_many(nr_reference, reference, all_flags);
        free_commit_list(bases);
        return ret;
}
int in_merge_bases(struct commit *commit, struct commit *reference)
{
        return in_merge_bases_many(commit, 1, &reference);
}
struct commit_list *reduce_heads(struct commit_list *heads)
{
        struct commit_list *p;
        struct commit_list *result = NULL, **tail = &result;
        struct commit **array;
        int num_head, i;
        if (!heads)
                return NULL;
        
        for (p = heads; p; p = p->next)
                p->item->object.flags &= ~STALE;
        for (p = heads, num_head = 0; p; p = p->next) {
                if (p->item->object.flags & STALE)
                        continue;
                p->item->object.flags |= STALE;
                num_head++;
        }
        array = xcalloc(num_head, sizeof(*array));
        for (p = heads, i = 0; p; p = p->next) {
                if (p->item->object.flags & STALE) {
                        array[i++] = p->item;
                        p->item->object.flags &= ~STALE;
                }
        }
        num_head = remove_redundant(array, num_head);
        for (i = 0; i < num_head; i++)
                tail = &commit_list_insert(array[i], tail)->next;
        return result;
}
static const char gpg_sig_header[] = "gpgsig";
static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
static int do_sign_commit(struct strbuf *buf, const char *keyid)
{
        struct strbuf sig = STRBUF_INIT;
        int inspos, copypos;
        
        inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
        if (!keyid || !*keyid)
                keyid = get_signing_key();
        if (sign_buffer(buf, &sig, keyid)) {
                strbuf_release(&sig);
                return -1;
        }
        for (copypos = 0; sig.buf[copypos]; ) {
                const char *bol = sig.buf + copypos;
                const char *eol = strchrnul(bol, '\n');
                int len = (eol - bol) + !!*eol;
                if (!copypos) {
                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
                        inspos += gpg_sig_header_len;
                }
                strbuf_insert(buf, inspos++, " ", 1);
                strbuf_insert(buf, inspos, bol, len);
                inspos += len;
                copypos += len;
        }
        strbuf_release(&sig);
        return 0;
}
int parse_signed_commit(const struct commit *commit,
                        struct strbuf *payload, struct strbuf *signature)
{
        unsigned long size;
        const char *buffer = get_commit_buffer(commit, &size);
        int in_signature, saw_signature = -1;
        const char *line, *tail;
        line = buffer;
        tail = buffer + size;
        in_signature = 0;
        saw_signature = 0;
        while (line < tail) {
                const char *sig = NULL;
                const char *next = memchr(line, '\n', tail - line);
                next = next ? next + 1 : tail;
                if (in_signature && line[0] == ' ')
                        sig = line + 1;
                else if (starts_with(line, gpg_sig_header) &&
                         line[gpg_sig_header_len] == ' ')
                        sig = line + gpg_sig_header_len + 1;
                if (sig) {
                        strbuf_add(signature, sig, next - sig);
                        saw_signature = 1;
                        in_signature = 1;
                } else {
                        if (*line == '\n')
                                
                                next = tail;
                        strbuf_add(payload, line, next - line);
                        in_signature = 0;
                }
                line = next;
        }
        unuse_commit_buffer(commit, buffer);
        return saw_signature;
}
int remove_signature(struct strbuf *buf)
{
        const char *line = buf->buf;
        const char *tail = buf->buf + buf->len;
        int in_signature = 0;
        const char *sig_start = NULL;
        const char *sig_end = NULL;
        while (line < tail) {
                const char *next = memchr(line, '\n', tail - line);
                next = next ? next + 1 : tail;
                if (in_signature && line[0] == ' ')
                        sig_end = next;
                else if (starts_with(line, gpg_sig_header) &&
                         line[gpg_sig_header_len] == ' ') {
                        sig_start = line;
                        sig_end = next;
                        in_signature = 1;
                } else {
                        if (*line == '\n')
                                
                                next = tail;
                        in_signature = 0;
                }
                line = next;
        }
        if (sig_start)
                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
        return sig_start != NULL;
}
static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
{
        struct merge_remote_desc *desc;
        struct commit_extra_header *mergetag;
        char *buf;
        unsigned long size, len;
        enum object_type type;
        desc = merge_remote_util(parent);
        if (!desc || !desc->obj)
                return;
        buf = read_sha1_file(desc->obj->sha1, &type, &size);
        if (!buf || type != OBJ_TAG)
                goto free_return;
        len = parse_signature(buf, size);
        if (size == len)
                goto free_return;
        
        mergetag = xcalloc(1, sizeof(*mergetag));
        mergetag->key = xstrdup("mergetag");
        mergetag->value = buf;
        mergetag->len = size;
        **tail = mergetag;
        *tail = &mergetag->next;
        return;
free_return:
        free(buf);
}
int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
{
        struct strbuf payload = STRBUF_INIT;
        struct strbuf signature = STRBUF_INIT;
        int ret = 1;
        sigc->result = 'N';
        if (parse_signed_commit(commit, &payload, &signature) <= 0)
                goto out;
        ret = check_signature(payload.buf, payload.len, signature.buf,
                signature.len, sigc);
 out:
        strbuf_release(&payload);
        strbuf_release(&signature);
        return ret;
}
void append_merge_tag_headers(struct commit_list *parents,
                              struct commit_extra_header ***tail)
{
        while (parents) {
                struct commit *parent = parents->item;
                handle_signed_tag(parent, tail);
                parents = parents->next;
        }
}
static void add_extra_header(struct strbuf *buffer,
                             struct commit_extra_header *extra)
{
        strbuf_addstr(buffer, extra->key);
        if (extra->len)
                strbuf_add_lines(buffer, " ", extra->value, extra->len);
        else
                strbuf_addch(buffer, '\n');
}
struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
                                                      const char **exclude)
{
        struct commit_extra_header *extra = NULL;
        unsigned long size;
        const char *buffer = get_commit_buffer(commit, &size);
        extra = read_commit_extra_header_lines(buffer, size, exclude);
        unuse_commit_buffer(commit, buffer);
        return extra;
}
void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
{
        struct commit_extra_header *extra, *to_free;
        to_free = read_commit_extra_headers(commit, NULL);
        for (extra = to_free; extra; extra = extra->next) {
                if (strcmp(extra->key, "mergetag"))
                        continue; 
                fn(commit, extra, data);
        }
        free_commit_extra_headers(to_free);
}
static inline int standard_header_field(const char *field, size_t len)
{
        return ((len == 4 && !memcmp(field, "tree ", 5)) ||
                (len == 6 && !memcmp(field, "parent ", 7)) ||
                (len == 6 && !memcmp(field, "author ", 7)) ||
                (len == 9 && !memcmp(field, "committer ", 10)) ||
                (len == 8 && !memcmp(field, "encoding ", 9)));
}
static int excluded_header_field(const char *field, size_t len, const char **exclude)
{
        if (!exclude)
                return 0;
        while (*exclude) {
                size_t xlen = strlen(*exclude);
                if (len == xlen &&
                    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
                        return 1;
                exclude++;
        }
        return 0;
}
static struct commit_extra_header *read_commit_extra_header_lines(
        const char *buffer, size_t size,
        const char **exclude)
{
        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
        const char *line, *next, *eof, *eob;
        struct strbuf buf = STRBUF_INIT;
        for (line = buffer, eob = line + size;
             line < eob && *line != '\n';
             line = next) {
                next = memchr(line, '\n', eob - line);
                next = next ? next + 1 : eob;
                if (*line == ' ') {
                        
                        if (it)
                                strbuf_add(&buf, line + 1, next - (line + 1));
                        continue;
                }
                if (it)
                        it->value = strbuf_detach(&buf, &it->len);
                strbuf_reset(&buf);
                it = NULL;
                eof = strchr(line, ' ');
                if (next <= eof)
                        eof = next;
                if (standard_header_field(line, eof - line) ||
                    excluded_header_field(line, eof - line, exclude))
                        continue;
                it = xcalloc(1, sizeof(*it));
                it->key = xmemdupz(line, eof-line);
                *tail = it;
                tail = &it->next;
                if (eof + 1 < next)
                        strbuf_add(&buf, eof + 1, next - (eof + 1));
        }
        if (it)
                it->value = strbuf_detach(&buf, &it->len);
        return extra;
}
void free_commit_extra_headers(struct commit_extra_header *extra)
{
        while (extra) {
                struct commit_extra_header *next = extra->next;
                free(extra->key);
                free(extra->value);
                free(extra);
                extra = next;
        }
}
int commit_tree(const char *msg, size_t msg_len,
                const unsigned char *tree,
                struct commit_list *parents, unsigned char *ret,
                const char *author, const char *sign_commit)
{
        struct commit_extra_header *extra = NULL, **tail = &extra;
        int result;
        append_merge_tag_headers(parents, &tail);
        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
                                      author, sign_commit, extra);
        free_commit_extra_headers(extra);
        return result;
}
static int find_invalid_utf8(const char *buf, int len)
{
        int offset = 0;
        static const unsigned int max_codepoint[] = {
                0x7f, 0x7ff, 0xffff, 0x10ffff
        };
        while (len) {
                unsigned char c = *buf++;
                int bytes, bad_offset;
                unsigned int codepoint;
                unsigned int min_val, max_val;
                len--;
                offset++;
                
                if (c < 0x80)
                        continue;
                bad_offset = offset-1;
                
                bytes = 0;
                while (c & 0x40) {
                        c <<= 1;
                        bytes++;
                }
                
                if (bytes < 1 || 3 < bytes)
                        return bad_offset;
                
                if (len < bytes)
                        return bad_offset;
                
                codepoint = (c & 0x7f) >> bytes;
                min_val = max_codepoint[bytes-1] + 1;
                max_val = max_codepoint[bytes];
                offset += bytes;
                len -= bytes;
                
                do {
                        codepoint <<= 6;
                        codepoint |= *buf & 0x3f;
                        if ((*buf++ & 0xc0) != 0x80)
                                return bad_offset;
                } while (--bytes);
                
                if (codepoint < min_val || codepoint > max_val)
                        return bad_offset;
                
                if ((codepoint & 0x1ff800) == 0xd800)
                        return bad_offset;
                
                if ((codepoint & 0xfffe) == 0xfffe)
                        return bad_offset;
                
                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
                        return bad_offset;
        }
        return -1;
}
static int verify_utf8(struct strbuf *buf)
{
        int ok = 1;
        long pos = 0;
        for (;;) {
                int bad;
                unsigned char c;
                unsigned char replace[2];
                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
                if (bad < 0)
                        return ok;
                pos += bad;
                ok = 0;
                c = buf->buf[pos];
                strbuf_remove(buf, pos, 1);
                
                replace[0] = 0xc0 + (c >> 6);
                replace[1] = 0x80 + (c & 0x3f);
                strbuf_insert(buf, pos, replace, 2);
                pos += 2;
        }
}
static const char commit_utf8_warn[] =
"Warning: commit message did not conform to UTF-8.\n"
"You may want to amend it after fixing the message, or set the config\n"
"variable i18n.commitencoding to the encoding your project uses.\n";
int commit_tree_extended(const char *msg, size_t msg_len,
                         const unsigned char *tree,
                         struct commit_list *parents, unsigned char *ret,
                         const char *author, const char *sign_commit,
                         struct commit_extra_header *extra)
{
        int result;
        int encoding_is_utf8;
        struct strbuf buffer;
        assert_sha1_type(tree, OBJ_TREE);
        if (memchr(msg, '\0', msg_len))
                return error("a NUL byte in commit log message not allowed.");
        
        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
        strbuf_init(&buffer, 8192); 
        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
        
        while (parents) {
                struct commit_list *next = parents->next;
                struct commit *parent = parents->item;
                strbuf_addf(&buffer, "parent %s\n",
                            sha1_to_hex(parent->object.sha1));
                free(parents);
                parents = next;
        }
        
        if (!author)
                author = git_author_info(IDENT_STRICT);
        strbuf_addf(&buffer, "author %s\n", author);
        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
        if (!encoding_is_utf8)
                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
        while (extra) {
                add_extra_header(&buffer, extra);
                extra = extra->next;
        }
        strbuf_addch(&buffer, '\n');
        
        strbuf_add(&buffer, msg, msg_len);
        
        if (encoding_is_utf8 && !verify_utf8(&buffer))
                fprintf(stderr, commit_utf8_warn);
        if (sign_commit && do_sign_commit(&buffer, sign_commit))
                return -1;
        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
        strbuf_release(&buffer);
        return result;
}
struct commit *get_merge_parent(const char *name)
{
        struct object *obj;
        struct commit *commit;
        struct object_id oid;
        if (get_sha1(name, oid.hash))
                return NULL;
        obj = parse_object(oid.hash);
        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
        if (commit && !commit->util) {
                struct merge_remote_desc *desc;
                desc = xmalloc(sizeof(*desc));
                desc->obj = obj;
                desc->name = strdup(name);
                commit->util = desc;
        }
        return commit;
}
struct commit_list **commit_list_append(struct commit *commit,
                                        struct commit_list **next)
{
        struct commit_list *new = xmalloc(sizeof(struct commit_list));
        new->item = commit;
        *next = new;
        new->next = NULL;
        return &new->next;
}
void print_commit_list(struct commit_list *list,
                       const char *format_cur,
                       const char *format_last)
{
        for ( ; list; list = list->next) {
                const char *format = list->next ? format_cur : format_last;
                printf(format, sha1_to_hex(list->item->object.sha1));
        }
}
const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
{
        int key_len = strlen(key);
        const char *line = msg;
        while (line) {
                const char *eol = strchrnul(line, '\n');
                if (line == eol)
                        return NULL;
                if (eol - line > key_len &&
                    !strncmp(line, key, key_len) &&
                    line[key_len] == ' ') {
                        *out_len = eol - line - key_len - 1;
                        return line + key_len + 1;
                }
                line = *eol ? eol + 1 : NULL;
        }
        return NULL;
}
int ignore_non_trailer(struct strbuf *sb)
{
        int boc = 0;
        int bol = 0;
        int in_old_conflicts_block = 0;
        while (bol < sb->len) {
                char *next_line;
                if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
                        next_line = sb->buf + sb->len;
                else
                        next_line++;
                if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
                        
                        if (!boc)
                                boc = bol;
                        
                } else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
                        in_old_conflicts_block = 1;
                        if (!boc)
                                boc = bol;
                } else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
                        ; 
                } else if (boc) {
                        
                        boc = 0;
                        in_old_conflicts_block = 0;
                }
                bol = next_line - sb->buf;
        }
        return boc ? sb->len - boc : 0;
}