Function append_fetch_head

builtin/fetch.c:1145–1189

}

static void append_fetch_head(struct fetch_head *fetch_head,
			      const struct object_id *old_oid,
			      enum fetch_head_status fetch_head_status,
			      const char *note,
			      const char *url, size_t url_len)
{
	char old_oid_hex[GIT_MAX_HEXSZ + 1];
	const char *merge_status_marker;
	size_t i;

	if (!fetch_head->fp)
		return;

	switch (fetch_head_status) {
	case FETCH_HEAD_NOT_FOR_MERGE:
		merge_status_marker = "not-for-merge";
		break;
	case FETCH_HEAD_MERGE:
		merge_status_marker = "";
		break;
	default:
		/* do not write anything to FETCH_HEAD */
		return;
	}

	strbuf_addf(&fetch_head->buf, "%s\t%s\t%s",
		    oid_to_hex_r(old_oid_hex, old_oid), merge_status_marker, note);
	for (i = 0; i < url_len; ++i)
		if ('\n' == url[i])
			strbuf_addstr(&fetch_head->buf, "\\n");
		else
			strbuf_addch(&fetch_head->buf, url[i]);
	strbuf_addch(&fetch_head->buf, '\n');

	/*
	 * When using an atomic fetch, we do not want to update FETCH_HEAD if
	 * any of the reference updates fails. We thus have to write all
	 * updates to a buffer first and only commit it as soon as all
	 * references have been successfully updated.
	 */
	if (!atomic_fetch) {
		strbuf_write(&fetch_head->buf, fetch_head->fp);
		strbuf_reset(&fetch_head->buf);
	}
}

static void commit_fetch_head(struct fetch_head *fetch_head)
{