repo_sidedata_extend
repo->rpmdbid = (Id *)repo_sidedata_extend(repo, repo->rpmdbid, sizeof(Id), p, 1);
repo->rpmdbid = (Id *)repo_sidedata_extend(repo, repo->rpmdbid, sizeof(Id), p, count);
extern void *repo_sidedata_extend(Repo *repo, void *b, size_t size, Id p, int count);