id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
14308	wp_insert_user in 3.0 is not backwards compatible	ahupp		"Prior to WP3.0 the function wp_insert_user would always return an integer or falsy on failure.  In 3.0 this function can return either an integer, or an instance of WP_Error.   This behavior is not backwards compatible and can result in bad results.

A function that expects an integer return value will treat this WP_Error instance as an integer, which results in a '1'.  This is the id of the administrator, resulting in possible corruption of the admin account.   In particular, calling wp_update_user() with this WP_Error value will cast the error to (int) and operate on the administrator.  First line of wp_update_user:

   $ID = (int) $userdata['ID'];

Possible resolutions:
  
 best: don't return WP_Error from wp_insert_user - this is not backwards compatible.  
 otherwise: check for is_wp_error() in wp_update_user(), and every other function that takes a user id.
"	defect (bug)	reopened	normal	Future Release	Users	3.0	normal		has-patch	ahupp