By default WordPress shortens two dashes or hyphens (–) to a single dash (-). Not very practical if you need to show a command that uses double-dash options such as the “–all-databases” in the previous post about mysqldump over ssh.
I found that this behavior could be altered by editing wp-includes/formatting.php and removing the third element of each of the arrays on line 73 and 74 ($static_characters and $static_replacements).