Undefined index: target in _link_sanitize()

I might get to submitting a patch later, but here's a quick report for now.

  // Remove the target attribute if the default (no target) is selected.
  if (empty($item['attributes']) || $item['attributes']['target'] == LINK_TARGET_DEFAULT) {
    unset($item['attributes']['target']);
  }

Should be something like:

  // Remove the target attribute if the default (no target) is selected.
  if (empty($item['attributes']) || isset($item['attributes']['target']) && $item['attributes']['target'] == LINK_TARGET_DEFAULT) {
    unset($item['attributes']['target']);
  }