wp_dropdown_users references user_login attribute that is never set

[sphoid]

When wp_dropdown_users is called and the internal foreach loop encounters as user with an empty value for the attribute indicated in $show it attempts to fallback on $user->user_login to show as the option text. When the fallback happens a php notice is triggered "Undefined property: stdClass::$user_login". By default get_users() is called with 'fields' = array('ID', $show) and by default $show is set to display_name so user_login is never an attribute of the queried users unless $show is set to user_login by some chance. I am attaching a patch that adds user_login to the fields argument

[sphoid]

Patch to add user_login to fields argument (wp-includes/user.php)

[ocean90]

Hello sphoid, thanks for your report and patch.

The bug is fixed in [24719].