Notice if arg passed is an array in author

[malthert]

If bots try urls like: /?author[]=1
The following code will give a notice:
Warning: preg_match() expects parameter 2 to be string, array given

} elseif ( is_author() && ! empty( $_GET['author'] ) && preg_match( '|^[0-9]+$|', $_GET['author'] ) ) {

Fix:

} elseif ( is_author() && ! empty( $_GET['author'] ) && ! is_array( $_GET['author'] ) && preg_match( '|^[0-9]+$|', $_GET['author'] ) ) {

[SergeyBiryukov]

Hi there, welcome back to WordPress Trac!

Thanks for the report, we're already tracking this issue in #17737.