_form_validate doesn't handle required file field correctly

I am building a form with a required file field as such:

…

$form["my-image"] = array(
	"#title"		=> t("Provide an image here"),
	"#type"		=> "file",
	"#required"	=> true,
);
$form["#attributes"]["enctype"] = "multipart/form-data";

…

In PHP, the file is correctly transmitted in the $_FILES autoglobal, although in a somewhat awkward structure, since Drupal renames the item to 'files[my-image]', which results in the attributes of the file being spread among the name, type, tmp_name, error, and size subarray, respectively, in the $_FILES array:

$_FILES:array(1) {
  ["files"]=>
  array(5) {
    ["name"]=>
    array(1) {
      ["my-image"]=>
      string(15) "drupal_logo.png"
    }
    ["type"]=>
    array(1) {
      ["my-image"]=>
      string(9) "image/png"
    }
    ["tmp_name"]=>
    array(1) {
      ["my-image"]=>
      string(32) "C:\Programme\xampp\tmp\php6D.tmp"
    }
    ["error"]=>
    array(1) {
      ["my-image"]=>
      int(0)
    }
    ["size"]=>
    array(1) {
      ["my-image"]=>
      int(2753)
    }
  }
}

_form_validate, though, doesn't check the $_FILES autoglobal in case of a required file form element, it just checks the value for the '#value' index of the element array, which is empty for attached files in multipart forms (that's why we have to define a different enctype in the first place, duh!).

Solution:
branch the code in _form_validate to check the $_FILES autoglobal in case of a required file field.

And please, branch the code for auto-naming file elements as well while you're at it, since it would be way easier to have all the name, type, tmp_name, error, and size information in one array for the form file element, not the other way round.

Thanks a lot,
Skiller