Issue #720876 by pillarsdotnet: user_register_validate() should invoke user_module_invoke() with an account object rather than an array; improved PHP 5.3 compatibility

Issue #1192178 by pillarsdotnet, jhodgdon: fix user_module_invoke() argument names to make more sense and phpdoc to document them (no behavioral change of course)

Issue #401266 by pillarsdotnet, jhodgdon: improve documentation on user_mail_tokens() to be more accurate on required account properties

Issue #107051 by webchick, gdevlugt, vladimir.dolgopolov, swentel, Dave Reid, tuffnatty, zyware, crifi, tobiasb: Fix for users showing multiple times in the who's online block

#365597 by JohnAlbin, Jody Lynn, mfb, zyxware, paul.lovvik: OpenID logins show Access denied after login due to redirection issues

#767512 by jhedstrom, Damien Tournoud, marvil07: make drupal_unpack() and user_save() more robust to avoid issues with empty keys in the data array

#259679 by pwolanin: add more specific checking to user_category_load() of the path, so the edit tab will show properly when seeing other tabs

#638702 by jhodgdon: fix issues where the return value of db_affected_rows() was not properly considered

#266488 by MadHarold, nbz, Damien Tournoud, sbandyopadhyay: fix some errors in username validation, clean up code style and add missing support for apostrophes

#770598 by greggles, grendzy: move user login failure attempt logging to user_authenticate() to have unified logging with all kinds of authentication schemes, including blogapi

#704158 by mikeytown2, marvil07 and myself: fix notice in user_preferred_language() when the user has no preferred language yet

#525504 by gpk, Dave Reid, sun: anonymous users should not have a contact form; also with added code documentation

#360605 by Berdir et al.: make Drupal core work with PHP 5.3.0 out of the box (fixes for incompatibilities introduced with PHP 5.3.0)

#530950 by catch, andypost: use \!isset() instead of is_null() in user_access() to be consistent and more performant

#318453 by svdoord and ahmed.othman, slightly modified: ensure that the user registration guidelines show above form fields added by the profile module by setting a low enough weight

#109588 by fago, cdale: use the existing user account objects instead of arg() checks, as well as fix use of  where it should be

#169937 by Heine, drumm, alexanderpas, Darren Oh: only regenerate session if the user is the current global user

#217957 by yched, quicksketch: header cell removal is broken when headers use colspans (and a little bit of performance improvement)

- Patch #259463 by dmitrig01: notification e-mail for pending user registrations had blank subject line.

#244597 by kbahey: remove cruft from user_login(), that added extra message to the form was never used or displayed