Notice: Trying to get property of non-object in user_access() (line 790 of ...user\user.module).

So, I have no idea what module was actually causing this problem. I suspect it might have been views or related, as that was what I was working with at the time; it just started one day when constructing custom views, and refused to go away. When attempting to dig out the root of the problem, I found that the user_access function was being called with the permissions request string twice by some module or another. Been fighting with xdebug, so I'm hard pressed to tell you which one.

Anyways, a minor modification of the beginning of the user_access function (line 790 of modules/user/user.module for me) from this:

function user_access($string, $account = NULL) {
  global $user;

  if (!isset($account)) {
    $account = $user;
  }

to this:

function user_access($string, $account = NULL) {
  global $user;

  if (!isset($account) || !is_object($account)) {
    $account = $user;
  }

seems to do the trick. Only someone who's spent time in core could tell me if this is a correct fix, but as the function is being called incorrectly if my fix is triggered *anyways*, it seems all right to me. *And*, it makes the problem go away...until the next core update, that is. Any core hackers want to opine if this is patch worthy?