/*
* Returns common ancesstor for two branches.
* Any two commits should have a common ancestor.
* So returning NULL indicates an error, for e.g. corupt commit.
*/
SeafCommit *
get_merge_base (SeafCommit *head, SeafCommit *remote)
{
GList *result, *iter;
SeafCommit *one, **twos;
int n, i;
SeafCommit *ret = NULL;
one = head;
twos = (SeafCommit **) calloc (1, sizeof(SeafCommit *));
twos[0] = remote;
n = 1;
result = merge_bases_many (one, n, twos);
free (twos);
if (!result || !result->next)
goto done;
/*
* More than one common ancestors.
* Loop until the oldest common ancestor is found.
*/
while (1) {
n = g_list_length (result) - 1;
g_assert (n > 0);
one = result->data;
twos = calloc (n, sizeof(SeafCommit *));
for (iter = result->next, i = 0; i < n; iter = iter->next, i++) {
twos[i] = iter->data;
}
g_list_free (result);
result = merge_bases_many (one, n, twos);
free (twos);
if (!result || !result->next)
break;
}
done:
if (result)
ret = result->data;
g_list_free (result);
return ret;
}
static GList *
get_independent_commits (GList *commits)
{
SeafCommit **rslt;
GList *list, *result;
int cnt, i, j;
SeafCommit *c;
g_debug ("Get independent commits.\n");
cnt = g_list_length (commits);
rslt = calloc(cnt, sizeof(*rslt));
for (list = commits, i = 0; list; list = list->next)
rslt[i++] = list->data;
g_list_free (commits);
for (i = 0; i < cnt - 1; i++) {
for (j = i+1; j < cnt; j++) {
if (!rslt[i] || !rslt[j])
continue;
result = merge_bases_many(rslt[i], 1, &rslt[j]);
for (list = result; list; list = list->next) {
c = list->data;
/* If two commits have fast-forward relationship,
* drop the older one.
*/
if (strcmp (rslt[i]->commit_id, c->commit_id) == 0) {
seaf_commit_unref (rslt[i]);
rslt[i] = NULL;
}
if (strcmp (rslt[j]->commit_id, c->commit_id) == 0) {
seaf_commit_unref (rslt[j]);
rslt[j] = NULL;
}
seaf_commit_unref (c);
}
}
}
/* Surviving ones in rslt[] are the independent results */
result = NULL;
for (i = 0; i < cnt; i++) {
if (rslt[i])
result = g_list_insert_sorted_with_data (result, rslt[i],
compare_commit_by_time,
NULL);
}
free(rslt);
return result;
}
