thodg/libgit2

diff --git a/src/blob.c b/src/blob.c
index c301ae1..65e1dd9 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -40,7 +40,7 @@ const char *git_blob_rawcontent(git_blob *blob)
 	if (blob->object.in_memory)
 		return NULL;
 
-	if (!blob->object.source.open && git_object__source_open((git_object *)blob) < 0)
+	if (!blob->object.source.open && git_object__source_open((git_object *)blob) < GIT_SUCCESS)
 		return NULL;
 
 	return blob->object.source.raw.data;
@@ -119,13 +119,13 @@ int git_blob_writefile(git_oid *written_id, git_repository *repo, const char *pa
 	if (gitfo_exists(path) < 0)
 		return GIT_ENOTFOUND;
 
-	if ((error = git_blob_new(&blob, repo)) < 0)
+	if ((error = git_blob_new(&blob, repo)) < GIT_SUCCESS)
 		return error;
 
-	if ((error = git_blob_set_rawcontent_fromfile(blob, path)) < 0)
+	if ((error = git_blob_set_rawcontent_fromfile(blob, path)) < GIT_SUCCESS)
 		return error;
 
-	if ((error = git_object_write((git_object *)blob)) < 0)
+	if ((error = git_object_write((git_object *)blob)) < GIT_SUCCESS)
 		return error;
 
 	git_oid_cpy(written_id, git_object_id((git_object *)blob));
diff --git a/src/commit.c b/src/commit.c
index dbb6926..7d21b88 100644
--- a/src/commit.c
+++ b/src/commit.c
@@ -114,23 +114,23 @@ int commit_parse_buffer(git_commit *commit, void *data, size_t len, unsigned int
 	clear_parents(commit);
 
 
-	if ((error = git__parse_oid(&oid, &buffer, buffer_end, "tree ")) < 0)
+	if ((error = git__parse_oid(&oid, &buffer, buffer_end, "tree ")) < GIT_SUCCESS)
 		return error;
 
-	if ((error = git_repository_lookup((git_object **)&commit->tree, commit->object.repo, &oid, GIT_OBJ_TREE)) < 0)
+	if ((error = git_repository_lookup((git_object **)&commit->tree, commit->object.repo, &oid, GIT_OBJ_TREE)) < GIT_SUCCESS)
 		return error;
 
 	/*
 	 * TODO: commit grafts!
 	 */
 
-	while (git__parse_oid(&oid, &buffer, buffer_end, "parent ") == 0) {
+	while (git__parse_oid(&oid, &buffer, buffer_end, "parent ") == GIT_SUCCESS) {
 		git_commit *parent;
 
-		if ((error = git_repository_lookup((git_object **)&parent, commit->object.repo, &oid, GIT_OBJ_COMMIT)) < 0)
+		if ((error = git_repository_lookup((git_object **)&parent, commit->object.repo, &oid, GIT_OBJ_COMMIT)) < GIT_SUCCESS)
 			return error;
 
-		if (git_vector_insert(&commit->parents, parent) < 0)
+		if (git_vector_insert(&commit->parents, parent) < GIT_SUCCESS)
 			return GIT_ENOMEM;
 	}
 
@@ -140,7 +140,7 @@ int commit_parse_buffer(git_commit *commit, void *data, size_t len, unsigned int
 			git_person__free(commit->author);
 
 		commit->author = git__malloc(sizeof(git_person));
-		if ((error = git_person__parse(commit->author, &buffer, buffer_end, "author ")) < 0)
+		if ((error = git_person__parse(commit->author, &buffer, buffer_end, "author ")) < GIT_SUCCESS)
 			return error;
 
 	} else {
@@ -155,7 +155,7 @@ int commit_parse_buffer(git_commit *commit, void *data, size_t len, unsigned int
 		git_person__free(commit->committer);
 
 	commit->committer = git__malloc(sizeof(git_person));
-	if ((error = git_person__parse(commit->committer, &buffer, buffer_end, "committer ")) < 0)
+	if ((error = git_person__parse(commit->committer, &buffer, buffer_end, "committer ")) < GIT_SUCCESS)
 		return error;
 
 	commit->commit_time = commit->committer->time;
@@ -199,9 +199,9 @@ int git_commit__parse_full(git_commit *commit)
 	int error;
 
 	if (commit->full_parse)
-		return 0;
+		return GIT_SUCCESS;
 
-	if ((error = git_object__source_open((git_object *)commit)) < 0)
+	if ((error = git_object__source_open((git_object *)commit)) < GIT_SUCCESS)
 		return error;
 
 	error = commit_parse_buffer(commit,
diff --git a/src/filelock.c b/src/filelock.c
index d831014..9db1cd7 100644
--- a/src/filelock.c
+++ b/src/filelock.c
@@ -49,7 +49,7 @@ int git_filelock_init(git_filelock *lock, const char *path)
 		return GIT_ERROR;
 
 	memcpy(lock->path, path, lock->path_length);
-	return 0;
+	return GIT_SUCCESS;
 }
 
 int git_filelock_lock(git_filelock *lock, int append)
@@ -85,7 +85,7 @@ int git_filelock_lock(git_filelock *lock, int append)
 		gitfo_close(source);
 	}
 
-	return 0;
+	return GIT_SUCCESS;
 }
 
 void git_filelock_unlock(git_filelock *lock)
@@ -116,7 +116,7 @@ int git_filelock_commit(git_filelock *lock)
 
 	error = gitfo_move_file(path_lock, lock->path);
 
-	if (error < 0)
+	if (error < GIT_SUCCESS)
 		gitfo_unlink(path_lock);
 
 	lock->is_locked = 0;
diff --git a/src/fileops.c b/src/fileops.c
index 210e7d6..ea9935a 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -151,7 +151,7 @@ int gitfo_move_file(char *from, char *to)
 
 int gitfo_map_ro(git_map *out, git_file fd, off_t begin, size_t len)
 {
-	if (git__mmap(out, len, GIT_PROT_READ, GIT_MAP_SHARED, fd, begin) < 0)
+	if (git__mmap(out, len, GIT_PROT_READ, GIT_MAP_SHARED, fd, begin) < GIT_SUCCESS)
 		return git_os_error();
 	return GIT_SUCCESS;
 }
@@ -240,7 +240,7 @@ int gitfo_close_cached(gitfo_cache *ioc)
 {
 	git_file fd;
 
-	if (gitfo_flush_cached(ioc) < 0)
+	if (gitfo_flush_cached(ioc) < GIT_SUCCESS)
 		return GIT_ERROR;
 
 	fd = ioc->fd;
@@ -292,7 +292,7 @@ int gitfo_dirent(
 
 		strcpy(path + wd_len, de->d_name);
 		result = fn(arg, path);
-		if (result < 0) {
+		if (result < GIT_SUCCESS) {
 			closedir(dir);
 			return result;
 		}
diff --git a/src/index.c b/src/index.c
index 488a60a..da22f70 100644
--- a/src/index.c
+++ b/src/index.c
@@ -196,14 +196,14 @@ void git_index_free(git_index *index)
 int git_index_read(git_index *index)
 {
 	struct stat indexst;
-	int error = 0;
+	int error = GIT_SUCCESS;
 
 	assert(index->index_file_path);
 
 	if (!index->on_disk || gitfo_exists(index->index_file_path) < 0) {
 		git_index_clear(index);
 		index->on_disk = 0;
-		return 0;
+		return GIT_SUCCESS;
 	}
 
 	if (gitfo_stat(index->index_file_path, &indexst) < 0)
@@ -216,13 +216,13 @@ int git_index_read(git_index *index)
 
 		gitfo_buf buffer;
 
-		if (gitfo_read_file(&buffer, index->index_file_path) < 0)
+		if (gitfo_read_file(&buffer, index->index_file_path) < GIT_SUCCESS)
 			return GIT_EOSERR;
 
 		git_index_clear(index);
 		error = git_index__parse(index, buffer.data, buffer.len);
 
-		if (error == 0)
+		if (error == GIT_SUCCESS)
 			index->last_modified = indexst.st_mtime;
 
 		gitfo_free_buf(&buffer);
@@ -239,18 +239,18 @@ int git_index_write(git_index *index)
 	if (!index->sorted)
 		git_index__sort(index);
 
-	if (git_filelock_init(&file, index->index_file_path) < 0)
+	if (git_filelock_init(&file, index->index_file_path) < GIT_SUCCESS)
 		return GIT_EFLOCKFAIL;
 
-	if (git_filelock_lock(&file, 0) < 0)
+	if (git_filelock_lock(&file, 0) < GIT_SUCCESS)
 		return GIT_EFLOCKFAIL;
 
-	if (git_index__write(index, &file) < 0) {
+	if (git_index__write(index, &file) < GIT_SUCCESS) {
 		git_filelock_unlock(&file);
 		return GIT_EOSERR;
 	}
 
-	if (git_filelock_commit(&file) < 0)
+	if (git_filelock_commit(&file) < GIT_SUCCESS)
 		return GIT_EFLOCKFAIL;
 
 	if (gitfo_stat(index->index_file_path, &indexst) == 0) {
@@ -258,7 +258,7 @@ int git_index_write(git_index *index)
 		index->on_disk = 1;
 	}
 
-	return 0;
+	return GIT_SUCCESS;
 }
 
 unsigned int git_index_entrycount(git_index *index)
@@ -310,7 +310,7 @@ int git_index_add(git_index *index, const char *rel_path, int stage)
 	entry.file_size = st.st_size;
 
 	/* write the blob to disk and get the oid */
-	if ((error = git_blob_writefile(&entry.oid, index->repository, full_path)) < 0)
+	if ((error = git_blob_writefile(&entry.oid, index->repository, full_path)) < GIT_SUCCESS)
 		return error;
 
 	entry.flags |= (stage << GIT_IDXENTRY_STAGESHIFT);
@@ -366,7 +366,7 @@ int git_index_insert(git_index *index, const git_index_entry *source_entry)
 	/* if no entry exists, add the entry at the end;
 	 * the index is no longer sorted */
 	if (position == GIT_ENOTFOUND) {
-		if (git_vector_insert(&index->entries, entry) < 0)
+		if (git_vector_insert(&index->entries, entry) < GIT_SUCCESS)
 			return GIT_ENOMEM;
 
 		index->sorted = 0;
@@ -480,7 +480,7 @@ static int read_tree(git_index *index, const char *buffer, size_t buffer_size)
 	const char *buffer_end = buffer + buffer_size;
 
 	index->tree = read_tree_internal(&buffer, buffer_end, NULL);
-	return (index->tree != NULL && buffer == buffer_end) ? 0 : GIT_EOBJCORRUPTED;
+	return (index->tree != NULL && buffer == buffer_end) ? GIT_SUCCESS : GIT_EOBJCORRUPTED;
 }
 
 static size_t read_entry(git_index_entry *dest, const void *buffer, size_t buffer_size)
@@ -561,7 +561,7 @@ static int read_header(struct index_header *dest, const void *buffer)
 		return GIT_EOBJCORRUPTED;
 
 	dest->entry_count = ntohl(source->entry_count);
-	return 0;
+	return GIT_SUCCESS;
 }
 
 static size_t read_extension(git_index *index, const char *buffer, size_t buffer_size)
@@ -585,7 +585,7 @@ static size_t read_extension(git_index *index, const char *buffer, size_t buffer
 		/* tree cache */
 		if (memcmp(dest.signature, INDEX_EXT_TREECACHE_SIG, 4) == 0) {
 
-			if (read_tree(index, buffer + 8, dest.extension_size) < 0)
+			if (read_tree(index, buffer + 8, dest.extension_size) < GIT_SUCCESS)
 				return 0;
 		}
 	} else {
@@ -618,7 +618,7 @@ int git_index__parse(git_index *index, const char *buffer, size_t buffer_size)
 	git_hash_buf(&checksum_calculated, (const void *)buffer, buffer_size - INDEX_FOOTER_SIZE);
 
 	/* Parse header */
-	if (read_header(&header, buffer) < 0)
+	if (read_header(&header, buffer) < GIT_SUCCESS)
 		return GIT_EOBJCORRUPTED;
 
 	seek_forward(INDEX_HEADER_SIZE);
@@ -640,7 +640,7 @@ int git_index__parse(git_index *index, const char *buffer, size_t buffer_size)
 		if (entry_size == 0)
 			return GIT_EOBJCORRUPTED;
 
-		if (git_vector_insert(&index->entries, entry) < 0)
+		if (git_vector_insert(&index->entries, entry) < GIT_SUCCESS)
 			return GIT_ENOMEM;
 
 		seek_forward(entry_size);
@@ -673,14 +673,14 @@ int git_index__parse(git_index *index, const char *buffer, size_t buffer_size)
 
 #undef seek_forward
 
-	return 0;
+	return GIT_SUCCESS;
 }
 
 int git_index__write(git_index *index, git_filelock *file)
 {
 	static const char NULL_BYTES[] = {0, 0, 0, 0, 0, 0, 0, 0};
 
-	int error = 0;
+	int error = GIT_SUCCESS;
 	unsigned int i;
 
 	git_hash_ctx *digest;
diff --git a/src/odb.c b/src/odb.c
index fd8c271..a905f6c 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -1178,7 +1178,7 @@ static int open_pack(git_pack *p)
 		goto error_cleanup;
 
 	if (!git__is_sizet(p->pack_size) ||
-		gitfo_map_ro(&p->pack_map, p->pack_fd, 0, (size_t)p->pack_size) < 0)
+		gitfo_map_ro(&p->pack_map, p->pack_fd, 0, (size_t)p->pack_size) < GIT_SUCCESS)
 		goto error_cleanup;
 
 	pack_decidx(p);
@@ -1261,25 +1261,25 @@ static int scan_one_pack(void *state, char *name)
 	if (git__prefixcmp(s + 1, "pack-")
 	 || git__suffixcmp(s, ".pack")
 	 || strlen(s + 1) != GIT_PACK_NAME_MAX + 4)
-		return 0;
+		return GIT_SUCCESS;
 
 	d = strrchr(s + 1, '.');
 	strcpy(d + 1, "idx");    /* "pack-abc.pack" -> "pack-abc.idx" */
 	if (gitfo_exists(name))
-		return 0;
+		return GIT_SUCCESS;
 
 	if ((r = git__malloc(sizeof(*r))) == NULL)
-		return GIT_ERROR;
+		return GIT_ERROR;  /* GIT_ENOMEM? */
 
 	*d = '\0';               /* "pack-abc.pack" -_> "pack-abc" */
 	if ((r->pack = alloc_pack(s + 1)) == NULL) {
 		free(r);
-		return GIT_ERROR;
+		return GIT_ERROR; /* GIT_ENOMEM? */
 	}
 
 	r->next = *ret;
 	*ret = r;
-	return 0;
+	return GIT_SUCCESS;
 }
 
 static git_packlist *scan_packs(git_odb *db)
@@ -1559,7 +1559,7 @@ static int open_alternates(git_odb *db)
 	db->alternates[n] = NULL;
 	db->n_alternates = n;
 	gitlck_unlock(&db->lock);
-	return 0;
+	return GIT_SUCCESS;
 }
 
 
@@ -1614,8 +1614,8 @@ static int read_header_packed(git_rawobj *out, const obj_location *loc)
 	if (pack_openidx(pack))
 		return GIT_EPACKCORRUPTED;
 
-	if (pack->idx_get(&e, pack, loc->pack.n) < 0 ||
-		open_pack(pack) < 0) {
+	if (pack->idx_get(&e, pack, loc->pack.n) < GIT_SUCCESS ||
+		open_pack(pack) < GIT_SUCCESS) {
 		error = GIT_ENOTFOUND;
 		goto cleanup;
 	}
@@ -1662,7 +1662,7 @@ static int read_loose(git_rawobj *out, git_odb *db, const obj_location *loc)
 	out->len  = 0;
 	out->type = GIT_OBJ_BAD;
 
-	if (gitfo_read_file(&obj, loc->loose_path) < 0)
+	if (gitfo_read_file(&obj, loc->loose_path) < GIT_SUCCESS)
 		return GIT_ENOTFOUND;
 
 	error = inflate_disk_obj(out, &obj);
@@ -1725,10 +1725,10 @@ static int write_obj(gitfo_buf *buf, git_oid *id, git_odb *db)
 	if (object_file_name(file, sizeof(file), db->objects_dir, id))
 		return GIT_EOSERR;
 
-	if (make_temp_file(&fd, temp, sizeof(temp), file) < 0)
+	if (make_temp_file(&fd, temp, sizeof(temp), file) < GIT_SUCCESS)
 		return GIT_EOSERR;
 
-	if (gitfo_write(fd, buf->data, buf->len) < 0) {
+	if (gitfo_write(fd, buf->data, buf->len) < GIT_SUCCESS) {
 		gitfo_close(fd);
 		gitfo_unlink(temp);
 		return GIT_EOSERR;
@@ -1739,7 +1739,7 @@ static int write_obj(gitfo_buf *buf, git_oid *id, git_odb *db)
 	gitfo_close(fd);
 	gitfo_chmod(temp, 0444);
 
-	if (gitfo_move_file(temp, file) < 0) {
+	if (gitfo_move_file(temp, file) < GIT_SUCCESS) {
 		gitfo_unlink(temp);
 		return GIT_EOSERR;
 	}
@@ -1839,7 +1839,7 @@ int git_odb_exists(git_odb *db, const git_oid *id)
 int git_odb_read_header(git_rawobj *out, git_odb *db, const git_oid *id)
 {
 	obj_location loc;
-	int found, error = 0;
+	int found, error = GIT_SUCCESS;
 
 	assert(out && db);
 
@@ -1868,7 +1868,7 @@ int git_odb_read(
 	const git_oid *id)
 {
 	obj_location loc;
-	int found, error = 0;
+	int found, error = GIT_SUCCESS;
 
 	assert(out && db);
 
@@ -1900,16 +1900,16 @@ int git_odb_write(git_oid *id, git_odb *db, git_rawobj *obj)
 
 	assert(id && db && obj);
 
-	if ((error = hash_obj(id, hdr, sizeof(hdr), &hdrlen, obj)) < 0)
+	if ((error = hash_obj(id, hdr, sizeof(hdr), &hdrlen, obj)) < GIT_SUCCESS)
 		return error;
 
 	if (git_odb_exists(db, id))
 		return GIT_SUCCESS;
 
-	if ((error = deflate_obj(&buf, hdr, hdrlen, obj, db->object_zlib_level)) < 0)
+	if ((error = deflate_obj(&buf, hdr, hdrlen, obj, db->object_zlib_level)) < GIT_SUCCESS)
 		return error;
 
-	if ((error = write_obj(&buf, id, db)) < 0) {
+	if ((error = write_obj(&buf, id, db)) < GIT_SUCCESS) {
 		gitfo_free_buf(&buf);
 		return error;
 	}
diff --git a/src/oid.c b/src/oid.c
index a14c935..f86098d 100644
--- a/src/oid.c
+++ b/src/oid.c
@@ -134,12 +134,12 @@ int git__parse_oid(git_oid *oid, char **buffer_out,
 	if (buffer[header_len + sha_len] != '\n')
 		return GIT_EOBJCORRUPTED;
 
-	if (git_oid_mkstr(oid, buffer + header_len) < 0)
+	if (git_oid_mkstr(oid, buffer + header_len) < GIT_SUCCESS)
 		return GIT_EOBJCORRUPTED;
 
 	*buffer_out = buffer + (header_len + sha_len + 1);
 
-	return 0;
+	return GIT_SUCCESS;
 }
 
 int git__write_oid(git_odb_source *src, const char *header, const git_oid *oid)
diff --git a/src/person.c b/src/person.c
index 0ab6a2d..9410913 100644
--- a/src/person.c
+++ b/src/person.c
@@ -129,7 +129,7 @@ int git_person__parse(git_person *person, char **buffer_out,
 		return GIT_EOBJCORRUPTED;
 
 	*buffer_out = (line_end + 1);
-	return 0;
+	return GIT_SUCCESS;
 }
 
 int git_person__write(git_odb_source *src, const char *header, const git_person *person)
diff --git a/src/repository.c b/src/repository.c
index c915ddd..eade02c 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -84,7 +84,7 @@ static int assign_repository_folders(git_repository *repo,
 
 	assert(repo);
 
-	if (git_dir == NULL || gitfo_isdir(git_dir) < 0)
+	if (git_dir == NULL || gitfo_isdir(git_dir) < GIT_SUCCESS)
 		return GIT_ENOTFOUND;
 
 
@@ -107,7 +107,7 @@ static int assign_repository_folders(git_repository *repo,
 	else
 		strcpy(path_aux, git_object_directory);
 
-	if (gitfo_isdir(path_aux) < 0)
+	if (gitfo_isdir(path_aux) < GIT_SUCCESS)
 		return GIT_ENOTFOUND;
 
 	repo->path_odb = git__strdup(path_aux);
@@ -139,7 +139,7 @@ static int guess_repository_folders(git_repository *repo, const char *repository
 	char path_aux[GIT_PATH_MAX], *last_folder;
 	int path_len;
 
-	if (gitfo_isdir(repository_path) < 0)
+	if (gitfo_isdir(repository_path) < GIT_SUCCESS)
 		return GIT_ENOTAREPO;
 
 	path_len = strlen(repository_path);
@@ -156,7 +156,7 @@ static int guess_repository_folders(git_repository *repo, const char *repository
 
 	/* objects database */
 	strcpy(path_aux + path_len, GIT_OBJECTS_FOLDER);
-	if (gitfo_isdir(path_aux) < 0)
+	if (gitfo_isdir(path_aux) < GIT_SUCCESS)
 		return GIT_ENOTAREPO;
 	repo->path_odb = git__strdup(path_aux);
 
@@ -233,11 +233,11 @@ int git_repository_open2(git_repository **repo_out,
 			git_index_file,
 			git_work_tree);
 
-	if (error < 0)
+	if (error < GIT_SUCCESS)
 		goto cleanup;
 
 	error = git_odb_open(&repo->db, repo->path_odb);
-	if (error < 0)
+	if (error < GIT_SUCCESS)
 		goto cleanup;
 
 	*repo_out = repo;
@@ -260,11 +260,11 @@ int git_repository_open(git_repository **repo_out, const char *path)
 		return GIT_ENOMEM;
 
 	error = guess_repository_folders(repo, path);
-	if (error < 0)
+	if (error < GIT_SUCCESS)
 		goto cleanup;
 
 	error = git_odb_open(&repo->db, repo->path_odb);
-	if (error < 0)
+	if (error < GIT_SUCCESS)
 		goto cleanup;
 
 	*repo_out = repo;
@@ -302,7 +302,7 @@ void git_repository_free(git_repository *repo)
 git_index *git_repository_index(git_repository *repo)
 {
 	if (repo->index == NULL) {
-		if (git_index_open_inrepo(&repo->index, repo) < 0)
+		if (git_index_open_inrepo(&repo->index, repo) < GIT_SUCCESS)
 			return NULL;
 
 		assert(repo->index);
@@ -344,7 +344,7 @@ int git__source_printf(git_odb_source *source, const char *format, ...)
 	len = vsnprintf(source->write_ptr, source->raw.len - source->written_bytes, format, arglist);
 
 	while (source->written_bytes + len >= source->raw.len) {
-		if (source_resize(source) < 0)
+		if (source_resize(source) < GIT_SUCCESS)
 			return GIT_ENOMEM;
 
 		did_resize = 1;
@@ -366,7 +366,7 @@ int git__source_write(git_odb_source *source, const void *bytes, size_t len)
 	assert(source->open && source->write_ptr);
 
 	while (source->written_bytes + len >= source->raw.len) {
-		if (source_resize(source) < 0)
+		if (source_resize(source) < GIT_SUCCESS)
 			return GIT_ENOMEM;
 	}
 
@@ -404,7 +404,7 @@ static int write_back(git_object *object)
 
 	object->source.raw.len = object->source.written_bytes;
 
-	if ((error = git_odb_write(&new_id, object->repo->db, &object->source.raw)) < 0)
+	if ((error = git_odb_write(&new_id, object->repo->db, &object->source.raw)) < GIT_SUCCESS)
 		return error;
 
 	if (!object->in_memory)
@@ -433,7 +433,7 @@ int git_object__source_open(git_object *object)
 		git_object__source_close(object);
 
 	error = git_odb_read(&object->source.raw, object->repo->db, &object->id);
-	if (error < 0)
+	if (error < GIT_SUCCESS)
 		return error;
 
 	object->source.open = 1;
@@ -485,7 +485,7 @@ int git_object_write(git_object *object)
 		break;
 	}
 
-	if (error < 0) {
+	if (error < GIT_SUCCESS) {
 		git_object__source_close(object);
 		return error;
 	}
@@ -590,7 +590,7 @@ int git_repository_lookup(git_object **object_out, git_repository *repo, const g
 {
 	git_object *object = NULL;
 	git_rawobj obj_file;
-	int error = 0;
+	int error = GIT_SUCCESS;
 
 	assert(repo && object_out && id);
 
@@ -601,7 +601,7 @@ int git_repository_lookup(git_object **object_out, git_repository *repo, const g
 	}
 
 	error = git_odb_read(&obj_file, repo->db, id);
-	if (error < 0)
+	if (error < GIT_SUCCESS)
 		return error;
 
 	if (type != GIT_OBJ_ANY && type != obj_file.type)
@@ -644,7 +644,7 @@ int git_repository_lookup(git_object **object_out, git_repository *repo, const g
 		break;
 	}
 
-	if (error < 0) {
+	if (error < GIT_SUCCESS) {
 		git_object_free(object);
 		return error;
 	}
diff --git a/src/tag.c b/src/tag.c
index f612cf3..920a72b 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -206,7 +206,7 @@ static int parse_tag_buffer(git_tag *tag, char *buffer, const char *buffer_end)
 	memcpy(tag->message, buffer, text_len);
 	tag->message[text_len] = '\0';
 
-	return 0;
+	return GIT_SUCCESS;
 }
 
 int git_tag__writeback(git_tag *tag, git_odb_source *src)
diff --git a/src/tree.c b/src/tree.c
index 2eeba72..a0138ca 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -238,12 +238,12 @@ static int tree_parse_buffer(git_tree *tree, char *buffer, char *buffer_end)
 {
 	static const size_t avg_entry_size = 40;
 	unsigned int expected_size;
-	int error = 0;
+	int error = GIT_SUCCESS;
 
 	expected_size = (tree->object.source.raw.len / avg_entry_size) + 1;
 
 	free_tree_entries(tree);
-	if (git_vector_init(&tree->entries, expected_size, entry_sort_cmp, entry_search_cmp) < 0)
+	if (git_vector_init(&tree->entries, expected_size, entry_sort_cmp, entry_search_cmp) < GIT_SUCCESS)
 		return GIT_ENOMEM;
 
 	while (buffer < buffer_end) {
@@ -255,7 +255,7 @@ static int tree_parse_buffer(git_tree *tree, char *buffer, char *buffer_end)
 			break;
 		}
 
-		if (git_vector_insert(&tree->entries, entry) < 0)
+		if (git_vector_insert(&tree->entries, entry) < GIT_SUCCESS)
 			return GIT_ENOMEM;
 
 		entry->owner = tree;