What does global $wp_hasher check for By the following check?
global $wp_hasher;
if ( empty($wp_hasher)
Is it to look if the user_pass filed contains the hashed password or not? How do I check if the user_pass got the password hash or not in the wp_hash_password function, while overwriting it from plugin?
$wp_hasheris empty (i.e., not set), WP uses the default implementation. If you want to use something different, that (i.e.,$wp_hasher) is what you alter. – t f Mar 14 at 23:29