The API page you've linked describes the format of the $patterns argument:

$patterns: String containing a set of patterns separated by \n, \r or \r\n.

These are types of carriage returns, in different Operating Systems.

Sooo .... did you try:

 $pattern = "portfolio/*\nphoto-blog";
 // or
 $pattern = "portfolio/*\rphoto-blog";
 // or
 $pattern = "portfolio/*\r\nphoto-blog";

The API page you've linked describes the format of the $patterns argument:

$patterns: String containing a set of patterns separated by \n, \r or \r\n.

These are types of carriage returns, in different Operating Systems.

Sooo .... did you try:

 $pattern = "portfolio/*\nphoto-blog";
 // or
 $pattern = "portfolio/*\rphoto-blog";
 // or
 $pattern = "portfolio/*\r\nphoto-blog";

EDIT:

 // for platform portability heh
 $pattern = "portfolio/*" . PHP_EOL . "photo-blog";