thodg/libgit2/src/describe.c

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• Hash : 0b5ba0d7
  Author :
  Date : 2019-06-06T16:36:23
  

  Rename opt init functions to `options_init` In libgit2 nomenclature, when we need to verb a direct object, we name a function `git_directobject_verb`. Thus, if we need to init an options structure named `git_foo_options`, then the name of the function that does that should be `git_foo_options_init`. The previous names of `git_foo_init_options` is close - it _sounds_ as if it's initializing the options of a `foo`, but in fact `git_foo_options` is its own noun that should be respected. Deprecate the old names; they'll now call directly to the new ones.

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• src/describe.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "common.h"
  
  #include "git2/describe.h"
  #include "git2/strarray.h"
  #include "git2/diff.h"
  #include "git2/status.h"
  
  #include "commit.h"
  #include "commit_list.h"
  #include "oidmap.h"
  #include "refs.h"
  #include "revwalk.h"
  #include "tag.h"
  #include "vector.h"
  #include "repository.h"
  
  /* Ported from https://github.com/git/git/blob/89dde7882f71f846ccd0359756d27bebc31108de/builtin/describe.c */
  
  struct commit_name {
  	git_tag *tag;
  	unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  	unsigned name_checked:1;
  	git_oid sha1;
  	char *path;
  
  	/* Khash workaround. They original key has to still be reachable */
  	git_oid peeled;
  };
  
  static void *oidmap_value_bykey(git_oidmap *map, const git_oid *key)
  {
  	return git_oidmap_get(map, key);
  }
  
  static struct commit_name *find_commit_name(
  	git_oidmap *names,
  	const git_oid *peeled)
  {
  	return (struct commit_name *)(oidmap_value_bykey(names, peeled));
  }
  
  static int replace_name(
  	git_tag **tag,
  	git_repository *repo,
  	struct commit_name *e,
  	unsigned int prio,
  	const git_oid *sha1)
  {
  	git_time_t e_time = 0, t_time = 0;
  
  	if (!e || e->prio < prio)
  		return 1;
  
  	if (e->prio == 2 && prio == 2) {
  		/* Multiple annotated tags point to the same commit.
  		 * Select one to keep based upon their tagger date.
  		 */
  		git_tag *t = NULL;
  
  		if (!e->tag) {
  			if (git_tag_lookup(&t, repo, &e->sha1) < 0)
  				return 1;
  			e->tag = t;
  		}
  
  		if (git_tag_lookup(&t, repo, sha1) < 0)
  			return 0;
  
  		*tag = t;
  
  		if (e->tag->tagger)
  			e_time = e->tag->tagger->when.time;
  
  		if (t->tagger)
  			t_time = t->tagger->when.time;
  
  		if (e_time < t_time)
  			return 1;
  	}
  
  	return 0;
  }
  
  static int add_to_known_names(
  	git_repository *repo,
  	git_oidmap *names,
  	const char *path,
  	const git_oid *peeled,
  	unsigned int prio,
  	const git_oid *sha1)
  {
  	struct commit_name *e = find_commit_name(names, peeled);
  	bool found = (e != NULL);
  
  	git_tag *tag = NULL;
  	if (replace_name(&tag, repo, e, prio, sha1)) {
  		if (!found) {
  			e = git__malloc(sizeof(struct commit_name));
  			GIT_ERROR_CHECK_ALLOC(e);
  
  			e->path = NULL;
  			e->tag = NULL;
  		}
  
  		if (e->tag)
  			git_tag_free(e->tag);
  		e->tag = tag;
  		e->prio = prio;
  		e->name_checked = 0;
  		git_oid_cpy(&e->sha1, sha1);
  		git__free(e->path);
  		e->path = git__strdup(path);
  		git_oid_cpy(&e->peeled, peeled);
  
  		if (!found && git_oidmap_set(names, &e->peeled, e) < 0)
  			return -1;
  	}
  	else
  		git_tag_free(tag);
  
  	return 0;
  }
  
  static int retrieve_peeled_tag_or_object_oid(
  	git_oid *peeled_out,
  	git_oid *ref_target_out,
  	git_repository *repo,
  	const char *refname)
  {
  	git_reference *ref;
  	git_object *peeled = NULL;
  	int error;
  
  	if ((error = git_reference_lookup_resolved(&ref, repo, refname, -1)) < 0)
  		return error;
  
  	if ((error = git_reference_peel(&peeled, ref, GIT_OBJECT_ANY)) < 0)
  		goto cleanup;
  
  	git_oid_cpy(ref_target_out, git_reference_target(ref));
  	git_oid_cpy(peeled_out, git_object_id(peeled));
  
  	if (git_oid_cmp(ref_target_out, peeled_out) != 0)
  		error = 1; /* The reference was pointing to a annotated tag */
  	else
  		error = 0; /* Any other object */
  
  cleanup:
  	git_reference_free(ref);
  	git_object_free(peeled);
  	return error;
  }
  
  struct git_describe_result {
  	int dirty;
  	int exact_match;
  	int fallback_to_id;
  	git_oid commit_id;
  	git_repository *repo;
  	struct commit_name *name;
  	struct possible_tag *tag;
  };
  
  struct get_name_data
  {
  	git_describe_options *opts;
  	git_repository *repo;
  	git_oidmap *names;
  	git_describe_result *result;
  };
  
  static int commit_name_dup(struct commit_name **out, struct commit_name *in)
  {
  	struct commit_name *name;
  
  	name = git__malloc(sizeof(struct commit_name));
  	GIT_ERROR_CHECK_ALLOC(name);
  
  	memcpy(name, in,  sizeof(struct commit_name));
  	name->tag = NULL;
  	name->path = NULL;
  
  	if (in->tag && git_tag_dup(&name->tag, in->tag) < 0)
  		return -1;
  
  	name->path = git__strdup(in->path);
  	GIT_ERROR_CHECK_ALLOC(name->path);
  
  	*out = name;
  	return 0;
  }
  
  static int get_name(const char *refname, void *payload)
  {
  	struct get_name_data *data;
  	bool is_tag, is_annotated, all;
  	git_oid peeled, sha1;
  	unsigned int prio;
  	int error = 0;
  
  	data = (struct get_name_data *)payload;
  	is_tag = !git__prefixcmp(refname, GIT_REFS_TAGS_DIR);
  	all = data->opts->describe_strategy == GIT_DESCRIBE_ALL;
  
  	/* Reject anything outside refs/tags/ unless --all */
  	if (!all && !is_tag)
  		return 0;
  
  	/* Accept only tags that match the pattern, if given */
  	if (data->opts->pattern && (!is_tag || p_fnmatch(data->opts->pattern,
  		refname + strlen(GIT_REFS_TAGS_DIR), 0)))
  				return 0;
  
  	/* Is it annotated? */
  	if ((error = retrieve_peeled_tag_or_object_oid(
  		&peeled, &sha1, data->repo, refname)) < 0)
  		return error;
  
  	is_annotated = error;
  
  	/*
  	 * By default, we only use annotated tags, but with --tags
  	 * we fall back to lightweight ones (even without --tags,
  	 * we still remember lightweight ones, only to give hints
  	 * in an error message).  --all allows any refs to be used.
  	 */
  	if (is_annotated)
  		prio = 2;
  	else if (is_tag)
  		prio = 1;
  	else
  		prio = 0;
  
  	add_to_known_names(data->repo, data->names,
  		all ? refname + strlen(GIT_REFS_DIR) : refname + strlen(GIT_REFS_TAGS_DIR),
  		&peeled, prio, &sha1);
  	return 0;
  }
  
  struct possible_tag {
  	struct commit_name *name;
  	int depth;
  	int found_order;
  	unsigned flag_within;
  };
  
  static int possible_tag_dup(struct possible_tag **out, struct possible_tag *in)
  {
  	struct possible_tag *tag;
  	int error;
  
  	tag = git__malloc(sizeof(struct possible_tag));
  	GIT_ERROR_CHECK_ALLOC(tag);
  
  	memcpy(tag, in, sizeof(struct possible_tag));
  	tag->name = NULL;
  
  	if ((error = commit_name_dup(&tag->name, in->name)) < 0) {
  		git__free(tag);
  		*out = NULL;
  		return error;
  	}
  
  	*out = tag;
  	return 0;
  }
  
  static int compare_pt(const void *a_, const void *b_)
  {
  	struct possible_tag *a = (struct possible_tag *)a_;
  	struct possible_tag *b = (struct possible_tag *)b_;
  	if (a->depth != b->depth)
  		return a->depth - b->depth;
  	if (a->found_order != b->found_order)
  		return a->found_order - b->found_order;
  	return 0;
  }
  
  #define SEEN (1u << 0)
  
  static unsigned long finish_depth_computation(
  	git_pqueue *list,
  	git_revwalk *walk,
  	struct possible_tag *best)
  {
  	unsigned long seen_commits = 0;
  	int error, i;
  
  	while (git_pqueue_size(list) > 0) {
  		git_commit_list_node *c = git_pqueue_pop(list);
  		seen_commits++;
  		if (c->flags & best->flag_within) {
  			size_t index = 0;
  			while (git_pqueue_size(list) > index) {
  				git_commit_list_node *i = git_pqueue_get(list, index);
  				if (!(i->flags & best->flag_within))
  					break;
  				index++;
  			}
  			if (index > git_pqueue_size(list))
  				break;
  		} else
  			best->depth++;
  		for (i = 0; i < c->out_degree; i++) {
  			git_commit_list_node *p = c->parents[i];
  			if ((error = git_commit_list_parse(walk, p)) < 0)
  				return error;
  			if (!(p->flags & SEEN))
  				if ((error = git_pqueue_insert(list, p)) < 0)
  					return error;
  			p->flags |= c->flags;
  		}
  	}
  	return seen_commits;
  }
  
  static int display_name(git_buf *buf, git_repository *repo, struct commit_name *n)
  {
  	if (n->prio == 2 && !n->tag) {
  		if (git_tag_lookup(&n->tag, repo, &n->sha1) < 0) {
  			git_error_set(GIT_ERROR_TAG, "annotated tag '%s' not available", n->path);
  			return -1;
  		}
  	}
  
  	if (n->tag && !n->name_checked) {
  		if (!git_tag_name(n->tag)) {
  			git_error_set(GIT_ERROR_TAG, "annotated tag '%s' has no embedded name", n->path);
  			return -1;
  		}
  
  		/* TODO: Cope with warnings
  		if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
  			warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
  		*/
  
  		n->name_checked = 1;
  	}
  
  	if (n->tag)
  		git_buf_printf(buf, "%s", git_tag_name(n->tag));
  	else
  		git_buf_printf(buf, "%s", n->path);
  
  	return 0;
  }
  
  static int find_unique_abbrev_size(
  	int *out,
  	git_repository *repo,
  	const git_oid *oid_in,
  	unsigned int abbreviated_size)
  {
  	size_t size = abbreviated_size;
  	git_odb *odb;
  	git_oid dummy;
  	int error;
  
  	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0)
  		return error;
  
  	while (size < GIT_OID_HEXSZ) {
  		if ((error = git_odb_exists_prefix(&dummy, odb, oid_in, size)) == 0) {
  			*out = (int) size;
  			return 0;
  		}
  
  		/* If the error wasn't that it's not unique, then it's a proper error */
  		if (error != GIT_EAMBIGUOUS)
  			return error;
  
  		/* Try again with a larger size */
  		size++;
  	}
  
  	/* If we didn't find any shorter prefix, we have to do the whole thing */
  	*out = GIT_OID_HEXSZ;
  
  	return 0;
  }
  
  static int show_suffix(
  	git_buf *buf,
  	int depth,
  	git_repository *repo,
  	const git_oid* id,
  	unsigned int abbrev_size)
  {
  	int error, size = 0;
  
  	char hex_oid[GIT_OID_HEXSZ];
  
  	if ((error = find_unique_abbrev_size(&size, repo, id, abbrev_size)) < 0)
  		return error;
  
  	git_oid_fmt(hex_oid, id);
  
  	git_buf_printf(buf, "-%d-g", depth);
  
  	git_buf_put(buf, hex_oid, size);
  
  	return git_buf_oom(buf) ? -1 : 0;
  }
  
  #define MAX_CANDIDATES_TAGS FLAG_BITS - 1
  
  static int describe_not_found(const git_oid *oid, const char *message_format) {
  	char oid_str[GIT_OID_HEXSZ + 1];
  	git_oid_tostr(oid_str, sizeof(oid_str), oid);
  
  	git_error_set(GIT_ERROR_DESCRIBE, message_format, oid_str);
  	return GIT_ENOTFOUND;
  }
  
  static int describe(
  	struct get_name_data *data,
  	git_commit *commit)
  {
  	struct commit_name *n;
  	struct possible_tag *best;
  	bool all, tags;
  	git_revwalk *walk = NULL;
  	git_pqueue list;
  	git_commit_list_node *cmit, *gave_up_on = NULL;
  	git_vector all_matches = GIT_VECTOR_INIT;
  	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
  	unsigned long seen_commits = 0;	/* TODO: Check long */
  	unsigned int unannotated_cnt = 0;
  	int error;
  
  	if (git_vector_init(&all_matches, MAX_CANDIDATES_TAGS, compare_pt) < 0)
  		return -1;
  
  	if ((error = git_pqueue_init(&list, 0, 2, git_commit_list_time_cmp)) < 0)
  		goto cleanup;
  
  	all = data->opts->describe_strategy == GIT_DESCRIBE_ALL;
  	tags = data->opts->describe_strategy == GIT_DESCRIBE_TAGS;
  
  	git_oid_cpy(&data->result->commit_id, git_commit_id(commit));
  
  	n = find_commit_name(data->names, git_commit_id(commit));
  	if (n && (tags || all || n->prio == 2)) {
  		/*
  		 * Exact match to an existing ref.
  		 */
  		data->result->exact_match = 1;
  		if ((error = commit_name_dup(&data->result->name, n)) < 0)
  			goto cleanup;
  
  		goto cleanup;
  	}
  
  	if (!data->opts->max_candidates_tags) {
  		error = describe_not_found(
  			git_commit_id(commit),
  			"cannot describe - no tag exactly matches '%s'");
  
  		goto cleanup;
  	}
  
  	if ((error = git_revwalk_new(&walk, git_commit_owner(commit))) < 0)
  		goto cleanup;
  
  	if ((cmit = git_revwalk__commit_lookup(walk, git_commit_id(commit))) == NULL)
  		goto cleanup;
  
  	if ((error = git_commit_list_parse(walk, cmit)) < 0)
  		goto cleanup;
  
  	cmit->flags = SEEN;
  
  	if ((error = git_pqueue_insert(&list, cmit)) < 0)
  		goto cleanup;
  
  	while (git_pqueue_size(&list) > 0)
  	{
  		int i;
  
  		git_commit_list_node *c = (git_commit_list_node *)git_pqueue_pop(&list);
  		seen_commits++;
  
  		n = find_commit_name(data->names, &c->oid);
  
  		if (n) {
  			if (!tags && !all && n->prio < 2) {
  				unannotated_cnt++;
  			} else if (match_cnt < data->opts->max_candidates_tags) {
  				struct possible_tag *t = git__malloc(sizeof(struct commit_name));
  				GIT_ERROR_CHECK_ALLOC(t);
  				if ((error = git_vector_insert(&all_matches, t)) < 0)
  					goto cleanup;
  
  				match_cnt++;
  
  				t->name = n;
  				t->depth = seen_commits - 1;
  				t->flag_within = 1u << match_cnt;
  				t->found_order = match_cnt;
  				c->flags |= t->flag_within;
  				if (n->prio == 2)
  					annotated_cnt++;
  			}
  			else {
  				gave_up_on = c;
  				break;
  			}
  		}
  
  		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
  			struct possible_tag *t = git_vector_get(&all_matches, cur_match);
  			if (!(c->flags & t->flag_within))
  				t->depth++;
  		}
  
  		if (annotated_cnt && (git_pqueue_size(&list) == 0)) {
  			/*
  			if (debug) {
  				char oid_str[GIT_OID_HEXSZ + 1];
  				git_oid_tostr(oid_str, sizeof(oid_str), &c->oid);
  
  				fprintf(stderr, "finished search at %s\n", oid_str);
  			}
  			*/
  			break;
  		}
  		for (i = 0; i < c->out_degree; i++) {
  			git_commit_list_node *p = c->parents[i];
  			if ((error = git_commit_list_parse(walk, p)) < 0)
  				goto cleanup;
  			if (!(p->flags & SEEN))
  				if ((error = git_pqueue_insert(&list, p)) < 0)
  					goto cleanup;
  			p->flags |= c->flags;
  
  			if (data->opts->only_follow_first_parent)
  				break;
  		}
  	}
  
  	if (!match_cnt) {
  		if (data->opts->show_commit_oid_as_fallback) {
  			data->result->fallback_to_id = 1;
  			git_oid_cpy(&data->result->commit_id, &cmit->oid);
  
  			goto cleanup;
  		}
  		if (unannotated_cnt) {
  			error = describe_not_found(git_commit_id(commit),
  				"cannot describe - "
  				"no annotated tags can describe '%s'; "
  			    "however, there were unannotated tags.");
  			goto cleanup;
  		}
  		else {
  			error = describe_not_found(git_commit_id(commit),
  				"cannot describe - "
  				"no tags can describe '%s'.");
  			goto cleanup;
  		}
  	}
  
  	git_vector_sort(&all_matches);
  
  	best = (struct possible_tag *)git_vector_get(&all_matches, 0);
  
  	if (gave_up_on) {
  		if ((error = git_pqueue_insert(&list, gave_up_on)) < 0)
  			goto cleanup;
  		seen_commits--;
  	}
  	if ((error = finish_depth_computation(
  		&list, walk, best)) < 0)
  		goto cleanup;
  
  	seen_commits += error;
  	if ((error = possible_tag_dup(&data->result->tag, best)) < 0)
  		goto cleanup;
  
  	/*
  	{
  		static const char *prio_names[] = {
  			"head", "lightweight", "annotated",
  		};
  
  		char oid_str[GIT_OID_HEXSZ + 1];
  
  		if (debug) {
  			for (cur_match = 0; cur_match < match_cnt; cur_match++) {
  				struct possible_tag *t = (struct possible_tag *)git_vector_get(&all_matches, cur_match);
  				fprintf(stderr, " %-11s %8d %s\n",
  					prio_names[t->name->prio],
  					t->depth, t->name->path);
  			}
  			fprintf(stderr, "traversed %lu commits\n", seen_commits);
  			if (gave_up_on) {
  				git_oid_tostr(oid_str, sizeof(oid_str), &gave_up_on->oid);
  				fprintf(stderr,
  					"more than %i tags found; listed %i most recent\n"
  					"gave up search at %s\n",
  					data->opts->max_candidates_tags, data->opts->max_candidates_tags,
  					oid_str);
  			}
  		}
  	}
  	*/
  
  	git_oid_cpy(&data->result->commit_id, &cmit->oid);
  
  cleanup:
  	{
  		size_t i;
  		struct possible_tag *match;
  		git_vector_foreach(&all_matches, i, match) {
  			git__free(match);
  		}
  	}
  	git_vector_free(&all_matches);
  	git_pqueue_free(&list);
  	git_revwalk_free(walk);
  	return error;
  }
  
  static int normalize_options(
  	git_describe_options *dst,
  	const git_describe_options *src)
  {
  	git_describe_options default_options = GIT_DESCRIBE_OPTIONS_INIT;
  	if (!src) src = &default_options;
  
  	*dst = *src;
  
  	if (dst->max_candidates_tags > GIT_DESCRIBE_DEFAULT_MAX_CANDIDATES_TAGS)
  		dst->max_candidates_tags = GIT_DESCRIBE_DEFAULT_MAX_CANDIDATES_TAGS;
  
  	return 0;
  }
  
  int git_describe_commit(
  	git_describe_result **result,
  	git_object *committish,
  	git_describe_options *opts)
  {
  	struct get_name_data data;
  	struct commit_name *name;
  	git_commit *commit;
  	int error = -1;
  	git_describe_options normalized;
  
  	assert(committish);
  
  	data.result = git__calloc(1, sizeof(git_describe_result));
  	GIT_ERROR_CHECK_ALLOC(data.result);
  	data.result->repo = git_object_owner(committish);
  
  	data.repo = git_object_owner(committish);
  
  	if ((error = normalize_options(&normalized, opts)) < 0)
  		return error;
  
  	GIT_ERROR_CHECK_VERSION(
  		&normalized,
  		GIT_DESCRIBE_OPTIONS_VERSION,
  		"git_describe_options");
  	data.opts = &normalized;
  
  	if ((error = git_oidmap_new(&data.names)) < 0)
  		return error;
  
  	/** TODO: contains to be implemented */
  
  	if ((error = git_object_peel((git_object **)(&commit), committish, GIT_OBJECT_COMMIT)) < 0)
  		goto cleanup;
  
  	if ((error = git_reference_foreach_name(
  			git_object_owner(committish),
  			get_name, &data)) < 0)
  				goto cleanup;
  
  	if (git_oidmap_size(data.names) == 0 && !opts->show_commit_oid_as_fallback) {
  		git_error_set(GIT_ERROR_DESCRIBE, "cannot describe - "
  			"no reference found, cannot describe anything.");
  		error = -1;
  		goto cleanup;
  	}
  
  	if ((error = describe(&data, commit)) < 0)
  		goto cleanup;
  
  cleanup:
  	git_commit_free(commit);
  
  	git_oidmap_foreach_value(data.names, name, {
  		git_tag_free(name->tag);
  		git__free(name->path);
  		git__free(name);
  	});
  
  	git_oidmap_free(data.names);
  
  	if (error < 0)
  		git_describe_result_free(data.result);
  	else
  		*result = data.result;
  
  	return error;
  }
  
  int git_describe_workdir(
  	git_describe_result **out,
  	git_repository *repo,
  	git_describe_options *opts)
  {
  	int error;
  	git_oid current_id;
  	git_status_list *status = NULL;
  	git_status_options status_opts = GIT_STATUS_OPTIONS_INIT;
  	git_describe_result *result = NULL;
  	git_object *commit;
  
  	if ((error = git_reference_name_to_id(&current_id, repo, GIT_HEAD_FILE)) < 0)
  		return error;
  
  	if ((error = git_object_lookup(&commit, repo, &current_id, GIT_OBJECT_COMMIT)) < 0)
  		return error;
  
  	/* The first step is to perform a describe of HEAD, so we can leverage this */
  	if ((error = git_describe_commit(&result, commit, opts)) < 0)
  		goto out;
  
  	if ((error = git_status_list_new(&status, repo, &status_opts)) < 0)
  		goto out;
  
  
  	if (git_status_list_entrycount(status) > 0)
  		result->dirty = 1;
  
  out:
  	git_object_free(commit);
  	git_status_list_free(status);
  
  	if (error < 0)
  		git_describe_result_free(result);
  	else
  		*out = result;
  
  	return error;
  }
  
  static int normalize_format_options(
  	git_describe_format_options *dst,
  	const git_describe_format_options *src)
  {
  	if (!src) {
  		git_describe_format_options_init(dst, GIT_DESCRIBE_FORMAT_OPTIONS_VERSION);
  		return 0;
  	}
  
  	memcpy(dst, src, sizeof(git_describe_format_options));
  	return 0;
  }
  
  int git_describe_format(git_buf *out, const git_describe_result *result, const git_describe_format_options *given)
  {
  	int error;
  	git_repository *repo;
  	struct commit_name *name;
  	git_describe_format_options opts;
  
  	assert(out && result);
  
  	GIT_ERROR_CHECK_VERSION(given, GIT_DESCRIBE_FORMAT_OPTIONS_VERSION, "git_describe_format_options");
  	normalize_format_options(&opts, given);
  
  	git_buf_sanitize(out);
  
  
  	if (opts.always_use_long_format && opts.abbreviated_size == 0) {
  		git_error_set(GIT_ERROR_DESCRIBE, "cannot describe - "
  			"'always_use_long_format' is incompatible with a zero"
  			"'abbreviated_size'");
  		return -1;
  	}
  
  
  	repo = result->repo;
  
  	/* If we did find an exact match, then it's the easier method */
  	if (result->exact_match) {
  		name = result->name;
  		if ((error = display_name(out, repo, name)) < 0)
  			return error;
  
  		if (opts.always_use_long_format) {
  			const git_oid *id = name->tag ? git_tag_target_id(name->tag) : &result->commit_id;
  			if ((error = show_suffix(out, 0, repo, id, opts.abbreviated_size)) < 0)
  				return error;
  		}
  
  		if (result->dirty && opts.dirty_suffix)
  			git_buf_puts(out, opts.dirty_suffix);
  
  		return git_buf_oom(out) ? -1 : 0;
  	}
  
  	/* If we didn't find *any* tags, we fall back to the commit's id */
  	if (result->fallback_to_id) {
  		char hex_oid[GIT_OID_HEXSZ + 1] = {0};
  		int size = 0;
  
  		if ((error = find_unique_abbrev_size(
  			     &size, repo, &result->commit_id, opts.abbreviated_size)) < 0)
  			return -1;
  
  		git_oid_fmt(hex_oid, &result->commit_id);
  		git_buf_put(out, hex_oid, size);
  
  		if (result->dirty && opts.dirty_suffix)
  			git_buf_puts(out, opts.dirty_suffix);
  
  		return git_buf_oom(out) ? -1 : 0;
  	}
  
  	/* Lastly, if we found a matching tag, we show that */
  	name = result->tag->name;
  
  	if ((error = display_name(out, repo, name)) < 0)
  		return error;
  
  	if (opts.abbreviated_size) {
  		if ((error = show_suffix(out, result->tag->depth, repo,
  			&result->commit_id, opts.abbreviated_size)) < 0)
  			return error;
  	}
  
  	if (result->dirty && opts.dirty_suffix) {
  		git_buf_puts(out, opts.dirty_suffix);
  	}
  
  	return git_buf_oom(out) ? -1 : 0;
  }
  
  void git_describe_result_free(git_describe_result *result)
  {
  	if (result == NULL)
  		return;
  
  	if (result->name) {
  		git_tag_free(result->name->tag);
  		git__free(result->name->path);
  		git__free(result->name);
  	}
  
  	if (result->tag) {
  		git_tag_free(result->tag->name->tag);
  		git__free(result->tag->name->path);
  		git__free(result->tag->name);
  		git__free(result->tag);
  	}
  
  	git__free(result);
  }
  
  int git_describe_options_init(git_describe_options *opts, unsigned int version)
  {
  	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
  		opts, version, git_describe_options, GIT_DESCRIBE_OPTIONS_INIT);
  	return 0;
  }
  
  int git_describe_init_options(git_describe_options *opts, unsigned int version)
  {
  	return git_describe_options_init(opts, version);
  }
  
  int git_describe_format_options_init(git_describe_format_options *opts, unsigned int version)
  {
  	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
  		opts, version, git_describe_format_options, GIT_DESCRIBE_FORMAT_OPTIONS_INIT);
  	return 0;
  }
  
  int git_describe_init_format_options(git_describe_format_options *opts, unsigned int version)
  {
  	return git_describe_format_options_init(opts, version);
  }
  

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