Function copy_previous_query

src/bin/psql/command.c:3035–3044

* If query_buf is empty, copy previous_buf into it. * * This is used by various slash commands for which re-execution of a * previous query is a common usage. For convenience, we allow the * case of query_buf == NULL (and do nothing). * * Returns "true" if the previous query was copied into the query * buffer, else "false". */

 * buffer, else "false".
 */
static bool
copy_previous_query(PQExpBuffer query_buf, PQExpBuffer previous_buf)
{
	if (query_buf && query_buf->len == 0)
	{
		appendPQExpBufferStr(query_buf, previous_buf->data);
		return true;
	}
	return false;
}

/*
 * Ask the user for a password; 'username' is the username the